1 files changed, 0 insertions, 20 deletions
diff --git a/lib/irb/command/exit.rb b/lib/irb/command/exit.rb
deleted file mode 100644
index 3109ec16e3..0000000000
--- a/lib/irb/command/exit.rb
+++ /dev/null
@@ -1,20 +0,0 @@
-# frozen_string_literal: true
-
-module IRB
-  # :stopdoc:
-
-  module Command
-    class Exit < Base
-      category "IRB"
-      description "Exit the current irb session."
-
-      def execute(*)
-        IRB.irb_exit
-      rescue UncaughtThrowError
-        Kernel.exit
-      end
-    end
-  end
-
-  # :startdoc:
-end
diff --git a/.dir-locals.el b/.dir-locals.el
index 7c32d1f7ee..8f4b96445c 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -24,6 +24,8 @@
 
  (c-mode . ((c-file-style . "ruby")))
 
+ (c++-mode . ((c-file-style . "ruby")))
+
  (change-log-mode .
      ((buffer-file-coding-system . us-ascii)
       (indent-tabs-mode . t)
diff --git a/.document b/.document
index 2116ca6d26..753d6f9892 100644
--- a/.document
+++ b/.document
@@ -9,28 +9,51 @@
 
 # prelude
 prelude.rb
-
 rbconfig.rb
 
+array.rb
+ast.rb
+dir.rb
+gc.rb
+hash.rb
+io.rb
+kernel.rb
+marshal.rb
+numeric.rb
+nilclass.rb
+pack.rb
+pathname_builtin.rb
+ractor.rb
+string.rb
+symbol.rb
+timev.rb
+thread_sync.rb
+trace_point.rb
+warning.rb
+yjit.rb
+zjit.rb
+
+# Errno::*
+known_errors.inc
+
 # the lib/ directory (which has its own .document file)
 lib
 
 # and some of the ext/ directory (which has its own .document file)
 ext
 
+# For `prism`, ruby code is in lib and c in the prism folder
+prism
+
 # rdoc files
-NEWS
+NEWS.md
 
 README.md
 README.ja.md
 
 COPYING
 COPYING.ja
-CONTRIBUTING.md
 
 LEGAL
 
-# win32/README.win32 linked from README.md
-win32
-
 doc
diff --git a/.gdbinit b/.gdbinit
index 0d44622691..4457f6f12b 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -1,23 +1,7 @@
-set startup-with-shell off
-
-define hook-run
-  set $color_type = 0
-  set $color_highlite = 0
-  set $color_end = 0
-end
-
 define ruby_gdb_init
-  if !$color_type
-    set $color_type = "\033[31m"
-  end
-  if !$color_highlite
-    set $color_highlite = "\033[36m"
-  end
-  if !$color_end
-    set $color_end = "\033[m"
-  end
-  if ruby_dummy_gdb_enums.special_consts
-  end
+  init-if-undefined $color_type = "\033[31m"
+  init-if-undefined $color_highlite = "\033[36m"
+  init-if-undefined $color_end = "\033[m"
 end
 
 # set prompt \033[36m(gdb)\033[m\040
@@ -67,7 +51,7 @@ define rp
     printf "%sT_OBJECT%s: ", $color_type, $color_end
     print ((struct RObject *)($arg0))->basic
     if ($flags & ROBJECT_EMBED)
-      print/x *((VALUE*)((struct RObject*)($arg0))->as.ary) @ (ROBJECT_EMBED_LEN_MAX+0)
+      print/x *((VALUE*)((struct RObject*)($arg0))->as.ary) @ (RSHAPE_CAPACITY(rb_obj_shape_id($arg0)))
     else
       print (((struct RObject *)($arg0))->as.heap)
       if (((struct RObject*)($arg0))->as.heap.numiv) > 0
@@ -99,13 +83,11 @@ define rp
     set $regsrc = ((struct RRegexp*)($arg0))->src
     set $rsflags = ((struct RBasic*)$regsrc)->flags
     printf "%sT_REGEXP%s: ", $color_type, $color_end
-    set $len = ($rsflags & RUBY_FL_USER1) ? \
-            ((struct RString*)$regsrc)->as.heap.len : \
-            (($rsflags & (RUBY_FL_USER2|RUBY_FL_USER3|RUBY_FL_USER4|RUBY_FL_USER5|RUBY_FL_USER6)) >> RUBY_FL_USHIFT+2)
+    set $len = ((struct RString*)($arg0))->len
     set print address off
     output *(char *)(($rsflags & RUBY_FL_USER1) ? \
-	    ((struct RString*)$regsrc)->as.heap.ptr : \
-	    ((struct RString*)$regsrc)->as.ary) @ $len
+            ((struct RString*)$regsrc)->as.heap.ptr : \
+            ((struct RString*)$regsrc)->as.embed.ary) @ $len
     set print address on
     printf " len:%ld ", $len
     if $flags & RUBY_FL_USER6
@@ -126,26 +108,26 @@ define rp
       printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
       printf "(embed) "
       if ($len == 0)
-	printf "{(empty)} "
+        printf "{(empty)} "
       else
-	print/x *((VALUE*)((struct RArray*)($arg0))->as.ary) @ $len
-	printf " "
+        print/x *((VALUE*)((struct RArray*)($arg0))->as.ary) @ $len
+        printf " "
       end
     else
       set $len = ((struct RArray*)($arg0))->as.heap.len
       printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
       if ($flags & RUBY_FL_USER2)
-	printf "(shared) shared="
-	output/x ((struct RArray*)($arg0))->as.heap.aux.shared
-	printf " "
+        printf "(shared) shared="
+        output/x ((struct RArray*)($arg0))->as.heap.aux.shared_root
+        printf " "
       else
-	printf "(ownership) capa=%ld ", ((struct RArray*)($arg0))->as.heap.aux.capa
+        printf "(ownership) capa=%ld ", ((struct RArray*)($arg0))->as.heap.aux.capa
       end
       if ($len == 0)
-	printf "{(empty)} "
+        printf "{(empty)} "
       else
-	print/x *((VALUE*)((struct RArray*)($arg0))->as.heap.ptr) @ $len
-	printf " "
+        print/x *((VALUE*)((struct RArray*)($arg0))->as.heap.ptr) @ $len
+        printf " "
       end
     end
     print (struct RArray *)($arg0)
@@ -156,14 +138,16 @@ define rp
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_HASH
     printf "%sT_HASH%s: ", $color_type, $color_end,
-    if (((struct RHash *)($arg0))->basic->flags & RHASH_ST_TABLE_FLAG)
-      printf "st len=%ld ", ((struct RHash *)($arg0))->as.st->num_entries
+    if (((struct RHash *)($arg0))->basic.flags & RHASH_ST_TABLE_FLAG)
+      set $st = (struct st_table *)((uintptr_t)($arg0) + sizeof(struct RHash))
+      printf "st len=%ld ", $st->num_entries
+      print $st
     else
       printf "li len=%ld bound=%ld ", \
-        ((((struct RHash *)($arg0))->basic->flags & RHASH_AR_TABLE_SIZE_MASK) >> RHASH_AR_TABLE_SIZE_SHIFT), \
-        ((((struct RHash *)($arg0))->basic->flags & RHASH_AR_TABLE_BOUND_MASK) >> RHASH_AR_TABLE_BOUND_SHIFT)
+        ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_SIZE_MASK) >> RHASH_AR_TABLE_SIZE_SHIFT), \
+        ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_BOUND_MASK) >> RHASH_AR_TABLE_BOUND_SHIFT)
+	print (struct ar_table_struct *)((uintptr_t)($arg0) + sizeof(struct RHash))
     end
-    print (struct RHash *)($arg0)
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_STRUCT
     set $len = (($flags & (RUBY_FL_USER1|RUBY_FL_USER2)) ? \
@@ -201,12 +185,14 @@ define rp
     print (struct RBasic *)($arg0)
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_DATA
-    if ((struct RTypedData *)($arg0))->typed_flag == 1
-      printf "%sT_DATA%s(%s): ", $color_type, $color_end, ((struct RTypedData *)($arg0))->type->wrap_struct_name
-      print (struct RTypedData *)($arg0)
+    set $data = (struct RTypedData *)($arg0)
+    set $type = (const rb_data_type_t *)($data->type & ~1)
+    printf "%sT_DATA%s(%s): ", $color_type, $color_end, $type->wrap_struct_name
+    print *$type
+    if ($data->type & 1)
+      print (void *)&$data->data
     else
-      printf "%sT_DATA%s: ", $color_type, $color_end
-      print (struct RData *)($arg0)
+      print $data
     end
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_MATCH
@@ -265,6 +251,10 @@ define rp
     printf "%sT_ZOMBIE%s: ", $color_type, $color_end
     print (struct RData *)($arg0)
   else
+  if ($flags & RUBY_T_MASK) == RUBY_T_MOVED
+    printf "%sT_MOVED%s: ", $color_type, $color_end
+    print *(struct RMoved *)$arg0
+  else
     printf "%sunknown%s: ", $color_type, $color_end
     print (struct RBasic *)($arg0)
   end
@@ -300,6 +290,7 @@ define rp
   end
   end
   end
+  end
 end
 document rp
   Print a Ruby's VALUE.
@@ -435,13 +426,11 @@ end
 
 define output_string
   set $flags = ((struct RBasic*)($arg0))->flags
-  set $len = ($flags & RUBY_FL_USER1) ? \
-          ((struct RString*)($arg0))->as.heap.len : \
-          (($flags & (RUBY_FL_USER2|RUBY_FL_USER3|RUBY_FL_USER4|RUBY_FL_USER5|RUBY_FL_USER6)) >> RUBY_FL_USHIFT+2)
+  set $len = ((struct RString*)($arg0))->len
   if $len > 0
     output *(char *)(($flags & RUBY_FL_USER1) ? \
-	    ((struct RString*)($arg0))->as.heap.ptr : \
-	    ((struct RString*)($arg0))->as.ary) @ $len
+            ((struct RString*)($arg0))->as.heap.ptr : \
+            ((struct RString*)($arg0))->as.embed.ary) @ $len
   else
     output ""
   end
@@ -449,13 +438,11 @@ end
 
 define print_string
   set $flags = ((struct RBasic*)($arg0))->flags
-  set $len = ($flags & RUBY_FL_USER1) ? \
-          ((struct RString*)($arg0))->as.heap.len : \
-          (($flags & (RUBY_FL_USER2|RUBY_FL_USER3|RUBY_FL_USER4|RUBY_FL_USER5|RUBY_FL_USER6)) >> RUBY_FL_USHIFT+2)
+  set $len = ((struct RString*)($arg0))->len
   if $len > 0
     printf "%s", *(char *)(($flags & RUBY_FL_USER1) ? \
-	    ((struct RString*)($arg0))->as.heap.ptr : \
-	    ((struct RString*)($arg0))->as.ary) @ $len
+            ((struct RString*)($arg0))->as.heap.ptr : \
+            ((struct RString*)($arg0))->as.embed.ary) @ $len
   end
 end
 
@@ -538,14 +525,14 @@ document rp_bignum
 end
 
 define rp_class
+  set $class_and_classext = (struct RClass_and_rb_classext_t *)($arg0)
   printf "(struct RClass *) %p", (void*)$arg0
-  if ((struct RClass *)($arg0))->ptr.origin_ != $arg0
-    printf " -> %p", ((struct RClass *)($arg0))->ptr.origin_
+  if $class_and_classext->classext->origin_ != (VALUE)$arg0
+    printf " -> %p", $class_and_classext->classext->origin_
   end
   printf "\n"
   rb_classname $arg0
-  print/x *(struct RClass *)($arg0)
-  print *((struct RClass *)($arg0))->ptr
+  print/x *$class_and_classext
 end
 document rp_class
   Print the content of a Class/Module.
@@ -684,11 +671,6 @@ define nd_stts
 end
 
 
-define nd_entry
-  printf "%su3.entry%s: ", $color_highlite, $color_end
-  p ($arg0).u3.entry
-end
-
 define nd_vid
   printf "%su1.id%s: ", $color_highlite, $color_end
   p ($arg0).u1.id
@@ -863,22 +845,22 @@ define rb_numtable_entry
     set $rb_numtable_p = $rb_numtable_tbl->as.packed.bins
     while $rb_numtable_p && $rb_numtable_p < $rb_numtable_tbl->as.packed.bins+$rb_numtable_tbl->num_entries
       if $rb_numtable_p.k == $rb_numtable_id
-	set $rb_numtable_key = $rb_numtable_p.k
-	set $rb_numtable_rec = $rb_numtable_p.v
-	set $rb_numtable_p = 0
+        set $rb_numtable_key = $rb_numtable_p.k
+        set $rb_numtable_rec = $rb_numtable_p.v
+        set $rb_numtable_p = 0
       else
-	set $rb_numtable_p = $rb_numtable_p + 1
+        set $rb_numtable_p = $rb_numtable_p + 1
       end
     end
   else
     set $rb_numtable_p = $rb_numtable_tbl->as.big.bins[st_numhash($rb_numtable_id) % $rb_numtable_tbl->num_bins]
     while $rb_numtable_p
       if $rb_numtable_p->key == $rb_numtable_id
-	set $rb_numtable_key = $rb_numtable_p->key
-	set $rb_numtable_rec = $rb_numtable_p->record
-	set $rb_numtable_p = 0
+        set $rb_numtable_key = $rb_numtable_p->key
+        set $rb_numtable_rec = $rb_numtable_p->record
+        set $rb_numtable_p = 0
       else
-	set $rb_numtable_p = $rb_numtable_p->next
+        set $rb_numtable_p = $rb_numtable_p->next
       end
     end
   end
@@ -916,10 +898,10 @@ document rb_method_entry
 end
 
 define rb_classname
-  # up to 128bit int
-  set $rb_classname = rb_mod_name($arg0)
-  if $rb_classname != RUBY_Qnil
-    rp $rb_classname
+  set $rb_classname = ((struct RClass_and_rb_classext_t*)$arg0)->classext->classpath
+  if $rb_classname != RUBY_Qfalse
+    print_string $rb_classname
+    printf "\n"
   else
     echo anonymous class/module\n
   end
@@ -956,7 +938,7 @@ define iseq
       set $operand_size = ((INSN*)($arg0))->operand_size
       set $operands = ((INSN*)($arg0))->operands
       while $i < $operand_size
-	rp $operands[$i++]
+        rp $operands[$i++]
       end
     end
   end
@@ -974,8 +956,8 @@ end
 
 define rb_ps_vm
   print $ps_vm = (rb_vm_t*)$arg0
-  set $ps_thread_ln = $ps_vm->living_threads.n.next
-  set $ps_thread_ln_last = $ps_vm->living_threads.n.prev
+  set $ps_thread_ln      = $ps_vm->ractor.main_ractor.threads.set.n.next
+  set $ps_thread_ln_last = $ps_vm->ractor.main_ractor.threads.set.n.prev
   while 1
     set $ps_thread_th = (rb_thread_t *)$ps_thread_ln
     set $ps_thread = (VALUE)($ps_thread_th->self)
@@ -992,7 +974,7 @@ end
 
 define print_lineno
   set $cfp = $arg0
-  set $iseq = $cfp->iseq
+  set $iseq = rb_get_cfp_iseq($cfp)
   set $pos = $cfp->pc - $iseq->body->iseq_encoded
   if $pos != 0
     set $pos = $pos - 1
@@ -1073,7 +1055,7 @@ define print_id
   else
     set $serial = (rb_id_serial_t)$id
   end
-  if $serial && $serial <= ruby_global_symbols.last_id
+  if $serial && $serial < ruby_global_symbols.next_id
     set $idx = $serial / ID_ENTRY_UNIT
     set $ids = (struct RArray *)ruby_global_symbols.ids
     set $flags = $ids->basic.flags
@@ -1096,12 +1078,12 @@ define print_id
           set $aryptr = $ary->as.heap.ptr
           set $arylen = $ary->as.heap.len
         end
-        set $result = $aryptr[($serial % ID_ENTRY_UNIT) * ID_ENTRY_SIZE + $t]
-	if $result != RUBY_Qnil
+        set $result = $aryptr[($serial % ID_ENTRY_UNIT) + $t]
+        if $result != RUBY_Qnil
           print_string $result
-	else
-	  echo undef
-	end
+        else
+          echo undef
+        end
       end
     end
   end
@@ -1126,20 +1108,21 @@ define rb_ps_thread
   set $ps_thread = (struct RTypedData*)$arg0
   set $ps_thread_th = (rb_thread_t*)$ps_thread->data
   printf "* #<Thread:%p rb_thread_t:%p native_thread:%p>\n", \
-    $ps_thread, $ps_thread_th, $ps_thread_th->thread_id
+    $ps_thread, $ps_thread_th, $ps_thread_th->nt
   set $cfp = $ps_thread_th->ec->cfp
   set $cfpend = (rb_control_frame_t *)($ps_thread_th->ec->vm_stack + $ps_thread_th->ec->vm_stack_size)-1
   while $cfp < $cfpend
-    if $cfp->iseq
-      if !((VALUE)$cfp->iseq & RUBY_IMMEDIATE_MASK) && (((imemo_ifunc << RUBY_FL_USHIFT) | RUBY_T_IMEMO)==$cfp->iseq->flags & ((RUBY_IMEMO_MASK << RUBY_FL_USHIFT) | RUBY_T_MASK))
+    if $cfp->_iseq
+      set $iseq = rb_get_cfp_iseq($cfp)
+      if !((VALUE)$iseq & RUBY_IMMEDIATE_MASK) && (((imemo_ifunc << RUBY_FL_USHIFT) | RUBY_T_IMEMO)==$iseq->flags & ((RUBY_IMEMO_MASK << RUBY_FL_USHIFT) | RUBY_T_MASK))
         printf "%d:ifunc ", $cfpend-$cfp
         set print symbol-filename on
-        output/a $cfp->iseq.body
+        output/a $iseq.body
         set print symbol-filename off
         printf "\n"
       else
       if $cfp->pc
-        set $location = $cfp->iseq->body->location
+        set $location = $iseq->body->location
         printf "%d:", $cfpend-$cfp
         print_pathobj $location.pathobj
         printf ":"
@@ -1274,9 +1257,9 @@ document rb_count_objects
   Counts all objects grouped by type.
 end
 
-# Details: https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/MachineInstructionsTraceWithGDB
+# Details: https://github.com/ruby/ruby/wiki/Machine-Instructions-Trace-with-GDB
 define trace_machine_instructions
-  set logging on
+  set logging enabled
   set height 0
   set width 0
   display/i $pc
@@ -1311,16 +1294,14 @@ define dump_node
   set $flags = ((struct RBasic*)($str))->flags
   printf "%s", (char *)(($flags & RUBY_FL_USER1) ? \
                         ((struct RString*)$str)->as.heap.ptr : \
-                        ((struct RString*)$str)->as.ary)
+                        ((struct RString*)$str)->as.embed.ary)
 end
 
 define print_flags
   printf "RUBY_FL_WB_PROTECTED: %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_WB_PROTECTED ? "1" : "0"
-  printf "RUBY_FL_PROMOTED0   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED0 ? "1" : "0"
-  printf "RUBY_FL_PROMOTED1   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED1 ? "1" : "0"
+  printf "RUBY_FL_PROMOTED    : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED ? "1" : "0"
   printf "RUBY_FL_FINALIZE    : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FINALIZE ? "1" : "0"
-  printf "RUBY_FL_TAINT       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_TAINT ? "1" : "0"
-  printf "RUBY_FL_UNTRUSTED   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_UNTRUSTED ? "1" : "0"
+  printf "RUBY_FL_SHAREABLE   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_SHAREABLE ? "1" : "0"
   printf "RUBY_FL_EXIVAR      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_EXIVAR ? "1" : "0"
   printf "RUBY_FL_FREEZE      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FREEZE ? "1" : "0"
 
@@ -1344,3 +1325,8 @@ define print_flags
   printf "RUBY_FL_USER17      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER17 ? "1" : "0"
   printf "RUBY_FL_USER18      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER18 ? "1" : "0"
 end
+
+source -s misc/gdb.py
+
+# Moved from beginning, since it fails on older gdbs
+set startup-with-shell off
diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
new file mode 100644
index 0000000000..d752612085
--- /dev/null
+++ b/.git-blame-ignore-revs
@@ -0,0 +1,54 @@
+# This is a file used by GitHub to ignore the following commits on `git blame`.
+#
+# You can also do the same thing in your local repository with:
+# $ git config --local blame.ignoreRevsFile .git-blame-ignore-revs
+
+# Expand tabs
+5b21e94bebed90180d8ff63dad03b8b948361089
+c5e9af9c9d890578182a21e7b71b50334cd5579e
+e63a2115f64433b21cb5dd67c5bf8b30f87ef293
+712ac99e4d0384a941c80a9f48f62943ba7d97c0
+d1474affa8e105bece209cc9d594bb0a989859e1
+2da92388b948821269b18d6b178a680f17e41750
+5062c0c621d887367af8a054e5e5d83d7ec57dd3
+
+# Indentation
+0e4bad888e605d424b9222ae0ca43f85c1634e5e
+61aa46c41648c6d1e9b0daa1a292de551fde78df
+
+# Enable Style/StringLiterals cop for RubyGems/Bundler
+d7ffd3fea402239b16833cc434404a7af82d44f3
+
+# [ruby/digest] Revert tab-expansion in external files
+48b09aae7ec5632209229dcc294dd0d75a93a17f
+8a65cf3b61c60e4cb886f59a73ff6db44364bfa9
+39dc9f9093901d40d2998653948d5da38b18ee2c
+
+# [ruby/io-nonblock] Revert tab expansion
+f28287d34c03f472ffe90ea262bdde9affd4b965
+0d842fecb4f75ab3b1d4097ebdb8e88f51558041
+4ba2c66761d6a293abdfba409241d31063cefd62
+
+# Make benchmark indentation consistent
+fc4acf8cae82e5196186d3278d831f2438479d91
+
+# Make prism_compile.c indentation consistent
+40b2c8e5e7e6e5f83cee9276dc9c1922a69292d6
+d2c5867357ed88eccc28c2b3bd4a46e206e7ff85
+
+# Miss-and-revived commits
+a0f7de814ae5c299d6ce99bed5fb308a05d50ba0
+d4e24021d39e1f80f0055b55d91f8d5f22e15084
+7a56c316418980b8a41fcbdc94067b2bda2ad112
+e90282be7ba1bc8e3119f6e1a2c80356ceb3f80a
+26a9e0b4e31f7b5a9cbd755e0a15823a8fa51bae
+2f53985da9ee593fe524d408256835667938c7d7
+bf01f6ae89a95d8f5572e050facfe311c8c28aaf
+7480cd8d37fd71a41ce12b759090051c7e14fb5a
+
+# Win32: EOL code of batch files
+23f9a0d655c4d405bb2397a147a1523436205486
+b839989fd22fef85e2af19de1bc83aa72a5b22bd
+
+# ZJIT cargo-insta snapshot raw string literals
+b78e0a6ddf7df8a7568ea71284f593423c739551
diff --git a/.gitattributes b/.gitattributes
index d0c2d266b4..f98c091e3f 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,8 +1,14 @@
 *.gemspec diff=ruby
 *.rb diff=ruby
+*.inc.rs linguist-generated=true
 bin svn-properties=svn:ignore=ruby
 bin/* diff=ruby
 tool/update-deps diff=ruby
 tool/make-snapshot diff=ruby
 tool/format-release diff=ruby
 tool/leaked-globals diff=ruby
+
+# To strip CR from the batch files, set the `diff.dos.textconv` filter
+# like as `git config diff.dos.textconv $'sed \'s/\r$//\''`.
+*.bat diff=dos
+*.cmd diff=dos
diff --git a/.github/SECURITY.md b/.github/SECURITY.md
new file mode 100644
index 0000000000..56baa29942
--- /dev/null
+++ b/.github/SECURITY.md
@@ -0,0 +1,9 @@
+# Security Policy
+
+## Supported Versions
+
+See <https://www.ruby-lang.org/en/downloads/branches/>.
+
+## Reporting a Vulnerability
+
+See <https://www.ruby-lang.org/en/security/>.
diff --git a/.github/actions/capiext/action.yml b/.github/actions/capiext/action.yml
new file mode 100644
index 0000000000..ed69c8ac5e
--- /dev/null
+++ b/.github/actions/capiext/action.yml
@@ -0,0 +1,86 @@
+name: rubyspec C-API extensions
+
+inputs:
+  builddir:
+    required: false
+    default: '.'
+  make:
+    required: false
+    default: 'make -s'
+
+outputs:
+  key:
+    value: >-
+      ${{
+      !steps.restore.outputs.cache-hit &&
+      github.ref == 'refs/heads/master' &&
+      steps.config.outputs.key
+      }}
+
+runs:
+  using: composite
+
+  steps:
+    - id: config
+      shell: bash
+      run: |
+        eval $(grep -e '^arch *=' -e '^ruby_version *=' -e '^DLEXT *=' Makefile |
+            sed 's/ *= */=/')
+        case "${ruby_version}" in
+        *+*) key=capiexts-${arch}-${ruby_version}-${{ hashFiles('src/spec/ruby/optional/capi/ext/*.[ch]') }};;
+        *)   key=;;
+        esac
+        echo version=$ruby_version >> $GITHUB_OUTPUT
+        echo key="$key" >> $GITHUB_OUTPUT
+        echo DLEXT=$DLEXT >> $GITHUB_OUTPUT
+      working-directory: ${{ inputs.builddir }}
+
+    - name: Restore previous CAPI extensions
+      uses: actions/cache/restore@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
+      id: cache
+      with:
+        path: ${{ inputs.builddir }}/spec/ruby/optional/capi/ext/
+        key: ${{ steps.config.outputs.key }}
+      if: ${{ steps.config.outputs.key }}
+
+    - name: Run test-spec with previous CAPI extension binaries
+      id: check
+      shell: bash
+      run: | # zizmor: ignore[template-injection]
+        touch spec/ruby/optional/capi/ext/*.$DLEXT
+        [ ! -f spec/ruby/optional/capi/ext/\*.$DLEXT ]
+        ${{ inputs.make }} SPECOPTS=optional/capi test-spec
+      env:
+        DLEXT: ${{ steps.config.outputs.DLEXT }}
+      working-directory: ${{ inputs.builddir }}
+      if: ${{ steps.cache.outputs.cache-hit }}
+
+    - name: Strip CAPI extensions
+      id: strip
+      shell: bash
+      run: |
+        rm -f spec/ruby/optional/capi/ext/*.c
+        [ "$DLEXT" = bundle ] || # separated to .dSYM directories
+        strip spec/ruby/optional/capi/ext/*.$DLEXT
+      env:
+        DLEXT: ${{ steps.config.outputs.DLEXT }}
+      working-directory: ${{ inputs.builddir }}
+      if: >-
+        ${{true
+        && ! steps.cache.outputs.cache-hit
+        && github.ref_name == 'master'
+        }}
+
+    - name: Save CAPI extensions
+      uses: actions/cache/save@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
+      with:
+        path: ${{ inputs.builddir }}/spec/ruby/optional/capi/ext/
+        key: ${{ steps.config.outputs.key }}
+      if: ${{ steps.strip.outcome == 'success' }}
+
+    - shell: bash
+      run: |
+        echo "::error::Change from ${prev} detected; bump up ABI version"
+      env:
+        prev: ${{ steps.config.outputs.version }}
+      if: ${{ always() && steps.check.outcome == 'failure' }}
diff --git a/.github/actions/compilers/action.yml b/.github/actions/compilers/action.yml
new file mode 100644
index 0000000000..c700bbfe9e
--- /dev/null
+++ b/.github/actions/compilers/action.yml
@@ -0,0 +1,164 @@
+name: Compiles ruby in a container
+description: >-
+  Makes ruby using a dedicated container
+
+inputs:
+  tag:
+    required: false
+    default: clang-20
+    description: >-
+      container image tag to use in this run.
+
+  with_gcc:
+    required: false
+    description: >-
+      override compiler path & flags.
+
+  CFLAGS:
+    required: false
+    description: >-
+      C compiler flags to override.
+
+  CXXFLAGS:
+    required: false
+    description: >-
+      C++ compiler flags to override.
+
+  optflags:
+    required: false
+    # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
+    # to optimize binaries.  Also GitHub Actions run on relatively modern CPUs
+    # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
+    # because compilers tend not understand what the CPU is.
+    default: '-O1'
+    description: >-
+      Compiler flags for optimisations.
+
+  cppflags:
+    required: false
+    description: >-
+      Additional preprocessor flags.
+
+  append_configure:
+    required: false
+    default: >-
+      --without-valgrind
+      --without-jemalloc
+      --without-gmp
+    description: >-
+      flags to append to configure.
+
+  enable_shared:
+    required: false
+    default: true
+    description: >-
+      Whether to build libruby.so.
+
+  check:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make check`
+
+  test_all:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make test-all` with options for test-all.
+
+  test_spec:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make test-spec` with options for mspec.
+
+  static_exts:
+    required: false
+    description: >-
+      whitespace separated list of extensions that need be linked statically.
+
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      run: docker pull --quiet "ghcr.io/ruby/ruby-ci-image:${INPUT_TAG}"
+      env:
+        INPUT_TAG: ${{ inputs.tag }}
+
+    - name: Enable Launchable conditionally
+      id: enable-launchable
+      run: echo "enable-launchable=true" >> $GITHUB_OUTPUT
+      shell: bash
+      if: >-
+        ${{
+        github.repository == 'ruby/ruby' ||
+        (github.repository != 'ruby/ruby' && env.LAUNCHABLE_TOKEN)
+        }}
+
+    - name: compile
+      shell: bash
+      run: >-
+        docker run
+        --rm
+        --user=root
+        --volume "${GITHUB_WORKSPACE}:/github/workspace:ro"
+        --workdir=/github/workspace
+        --entrypoint=/github/workspace/.github/actions/compilers/entrypoint.sh
+        --env CI
+        --env GITHUB_ACTION
+        --env INPUT_WITH_GCC
+        --env INPUT_CFLAGS
+        --env INPUT_CXXFLAGS
+        --env INPUT_OPTFLAGS
+        --env INPUT_CPPFLAGS
+        --env INPUT_APPEND_CONFIGURE
+        --env INPUT_CHECK
+        --env INPUT_TEST_ALL
+        --env INPUT_TEST_SPEC
+        --env INPUT_ENABLE_SHARED
+        --env INPUT_STATIC_EXTS
+        --env LAUNCHABLE_ORGANIZATION
+        --env LAUNCHABLE_WORKSPACE
+        --env LAUNCHABLE_ENABLED
+        --env GITHUB_PR_HEAD_SHA
+        --env GITHUB_PULL_REQUEST_URL
+        --env GITHUB_REF
+        --env GITHUB_ACTIONS
+        --env GITHUB_RUN_ID
+        --env GITHUB_REPOSITORY
+        --env GITHUB_WORKFLOW
+        --env GITHUB_RUN_NUMBER
+        --env GITHUB_EVENT_NAME
+        --env GITHUB_SHA
+        --env GITHUB_HEAD_REF
+        --env GITHUB_SERVER_URL
+        "ghcr.io/ruby/ruby-ci-image:${INPUT_TAG}"
+      env:
+        INPUT_TAG: ${{ inputs.tag }}
+        INPUT_WITH_GCC: ${{ inputs.with_gcc || inputs.tag }}
+        INPUT_CFLAGS: ${{ inputs.CFLAGS }}
+        INPUT_CXXFLAGS: ${{ inputs.CXXFLAGS }}
+        INPUT_OPTFLAGS: ${{ inputs.OPTFLAGS }}
+        INPUT_CPPFLAGS: ${{ inputs.cppflags }}
+        INPUT_APPEND_CONFIGURE: ${{ inputs.append_configure }}
+        INPUT_CHECK: ${{ inputs.check }}
+        INPUT_TEST_ALL: ${{ inputs.test_all }}
+        INPUT_TEST_SPEC: ${{ inputs.test_spec }}
+        INPUT_ENABLE_SHARED: ${{ inputs.enable_shared }}
+        INPUT_STATIC_EXTS: ${{ inputs.static_exts }}
+        LAUNCHABLE_ORGANIZATION: ${{ github.repository_owner }}
+        LAUNCHABLE_WORKSPACE: ${{ github.event.repository.name }}
+        LAUNCHABLE_ENABLED: ${{ steps.enable-launchable.outputs.enable-launchable || false }}
+        GITHUB_PR_HEAD_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
+        GITHUB_PULL_REQUEST_URL: ${{ github.event.pull_request.html_url }}
+        GITHUB_REF: ${{ github.ref }}
+
+    # Clean up non-default docker images to save disk space.
+    # The default image (clang-20) is reused across multiple steps
+    # within the same job, so we keep it to avoid redundant pulls.
+    - name: clean up docker image
+      shell: bash
+      run: docker rmi "ghcr.io/ruby/ruby-ci-image:${INPUT_TAG}" || true
+      if: ${{ always() && inputs.tag != 'clang-20' }}
+      env:
+        INPUT_TAG: ${{ inputs.tag }}
diff --git a/.github/actions/compilers/entrypoint.sh b/.github/actions/compilers/entrypoint.sh
new file mode 100755
index 0000000000..b554151091
--- /dev/null
+++ b/.github/actions/compilers/entrypoint.sh
@@ -0,0 +1,90 @@
+#! /bin/bash
+
+# Copyright (c) 2024 Ruby developers.  All rights reserved.
+#
+# This file is  a part of the programming language  Ruby.  Permission is hereby
+# granted, to  either redistribute and/or  modify this file, provided  that the
+# conditions  mentioned in  the file  COPYING are  met.  Consult  the file  for
+# details.
+
+grouped()
+{
+    echo "::group::${@}"
+    "${@}"
+    echo "::endgroup::"
+}
+
+set -e
+set -u
+set -o pipefail
+
+srcdir="/github/workspace/src"
+builddir="$(mktemp -dt)"
+
+export GITHUB_WORKFLOW='Compilations'
+export CONFIGURE_TTY='never'
+export RUBY_DEBUG='ci rgengc'
+export RUBY_TESTOPTS='-q --color=always --tty=no'
+export RUBY_DEBUG_COUNTER_DISABLE='1'
+export GNUMAKEFLAGS="-j$((1 + $(nproc)))"
+
+case "x${INPUT_ENABLE_SHARED}" in
+x | xno | xfalse )
+    enable_shared='--disable-shared'
+    ;;
+*)
+    enable_shared='--enable-shared'
+    ;;
+esac
+
+pushd ${builddir}
+
+grouped git config --global --add safe.directory ${srcdir}
+
+grouped ${srcdir}/configure        \
+    -C                             \
+    --with-gcc="${INPUT_WITH_GCC}" \
+    --enable-debug-env             \
+    --disable-install-doc          \
+    --with-ext=-test-/cxxanyargs,+ \
+    --without-git                  \
+    ${enable_shared}               \
+    ${INPUT_APPEND_CONFIGURE}      \
+    CFLAGS="${INPUT_CFLAGS}"       \
+    CXXFLAGS="${INPUT_CXXFLAGS}"   \
+    optflags="${INPUT_OPTFLAGS}"   \
+    cppflags="${INPUT_CPPFLAGS}"   \
+    debugflags='-ggdb3' # -g0 disables backtraces when SEGV.  Do not set that.
+
+popd
+
+if [[ -n "${INPUT_STATIC_EXTS}" ]]; then
+    echo "::group::ext/Setup"
+    set -x
+    mkdir ${builddir}/ext
+    (
+        for ext in ${INPUT_STATIC_EXTS}; do
+            echo "${ext}"
+        done
+    ) >> ${builddir}/ext/Setup
+    set +x
+    echo "::endgroup::"
+fi
+
+if [ -n "$INPUT_TEST_ALL" ]; then
+  tests=" -- $INPUT_TEST_ALL"
+else
+  tests=" -- ruby -ext-"
+fi
+
+pushd ${builddir}
+
+grouped make showflags
+grouped make all
+# grouped make install
+
+# Run only `make test` by default. Run other tests if specified.
+grouped make test
+if [[ -n "$INPUT_CHECK" ]]; then grouped make test-tool; fi
+if [[ -n "$INPUT_CHECK" || -n "$INPUT_TEST_ALL" ]]; then grouped make test-all TESTS="$tests"; fi
+if [[ -n "$INPUT_CHECK" || -n "$INPUT_TEST_SPEC" ]]; then grouped env CHECK_LEAKS=true make test-spec MSPECOPT="$INPUT_TEST_SPEC"; fi
diff --git a/.github/actions/launchable/setup/action.yml b/.github/actions/launchable/setup/action.yml
new file mode 100644
index 0000000000..305878492c
--- /dev/null
+++ b/.github/actions/launchable/setup/action.yml
@@ -0,0 +1,337 @@
+name: Set up Launchable
+description: >-
+  Install the required dependencies and execute the necessary Launchable commands for test recording
+
+inputs:
+  os:
+    required: true
+    description: The operating system that CI runs on. This value is used in Launchable flavor.
+
+  test-opts:
+    default: none
+    required: false
+    description: >-
+      Test options that determine how tests are run.
+      This value is used in the Launchable flavor.
+
+  launchable-token:
+    required: false
+    description: >-
+      Launchable token is needed if you want to run Launchable on your forked repository.
+      See https://github.com/ruby/ruby/wiki/CI-Servers#launchable-ci for details.
+
+  builddir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Directory to create Launchable report file.
+
+  srcdir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Directory to (re-)checkout source codes. Launchable retrieves the commit information
+      from the directory.
+
+  test-task:
+    required: false
+    default: ${{ matrix.test_task }}
+    description: >-
+      Specifies a single test task to be executed.
+      This value is used in the Launchable flavor.
+      Either 'test-task' or 'multi-test-tasks' must be configured.
+
+  test-tasks:
+    required: false
+    default: '[]'
+    description: >-
+      Specifies an array of multiple test tasks to be executed.
+      For example: '["test", "test-all"]'.
+      If you want to run a single test task, use the 'test-task' input instead.
+
+  is-yjit:
+    required: false
+    default: 'false'
+    description: >-
+      Whether this workflow is executed on YJIT.
+
+  is-zjit:
+    required: false
+    default: 'false'
+    description: >-
+      Whether this workflow is executed on ZJIT.
+
+outputs:
+  stdout_report_path:
+    value: ${{ steps.global.outputs.stdout_report_path }}
+    description: >-
+      Report file path for standard output.
+
+  stderr_report_path:
+    value: ${{ steps.global.outputs.stderr_report_path }}
+    description: >-
+      Report file path for standard error.
+
+runs:
+  using: composite
+
+  steps:
+    - name: Enable Launchable conditionally
+      id: enable-launchable
+      run: echo "enable-launchable=true" >> $GITHUB_OUTPUT
+      shell: bash
+      if: >-
+        ${{
+        (github.repository == 'ruby/ruby'
+          || (github.repository != 'ruby/ruby'
+          && env.LAUNCHABLE_TOKEN))
+        && (inputs.test-task == 'check'
+          || inputs.test-task == 'test-all'
+          || inputs.test-task == 'test'
+          || contains(fromJSON(inputs.test-tasks), 'test-all')
+          || contains(fromJSON(inputs.test-tasks), 'test'))
+        }}
+
+    # Launchable CLI requires Python and Java.
+    # https://www.launchableinc.com/docs/resources/cli-reference/
+    - name: Set up Python
+      uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      with:
+        python-version: "3.x"
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && !endsWith(inputs.os, 'ppc64le') && !endsWith(inputs.os, 's390x') }}
+
+    - name: Set up Java
+      uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4.8.0
+      with:
+        distribution: 'temurin'
+        java-version: '17'
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && !endsWith(inputs.os, 'ppc64le') && !endsWith(inputs.os, 's390x') }}
+
+    - name: Set up Java ppc64le
+      uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4.8.0
+      with:
+        distribution: 'semeru'
+        architecture: 'ppc64le'
+        java-version: '17'
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && endsWith(inputs.os, 'ppc64le') }}
+
+    - name: Set up Java s390x
+      uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4.8.0
+      with:
+        distribution: 'semeru'
+        architecture: 's390x'
+        java-version: '17'
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && endsWith(inputs.os, 's390x') }}
+
+    - name: Set global vars
+      id: global
+      shell: bash
+      run: |
+        test_all_enabled="${{ inputs.test-task == 'check' ||  inputs.test-task == 'test-all' || contains(fromJSON(inputs.test-tasks), 'test-all') }}"
+        btest_enabled="${{ inputs.test-task == 'check' ||  inputs.test-task == 'test' || contains(fromJSON(inputs.test-tasks), 'test') }}"
+        test_spec_enabled="${{ inputs.test-task == 'check' ||  inputs.test-task == 'test-spec' || contains(fromJSON(inputs.test-tasks), 'test-spec') }}"
+        echo test_all_enabled="${test_all_enabled}" >> $GITHUB_OUTPUT
+        echo btest_enabled="${btest_enabled}" >> $GITHUB_OUTPUT
+        echo test_spec_enabled="${test_spec_enabled}" >> $GITHUB_OUTPUT
+        echo test_all_report_file='launchable_test_all_report.json' >> $GITHUB_OUTPUT
+        echo btest_report_file='launchable_btest_report.json' >> $GITHUB_OUTPUT
+        echo test_spec_report_dir='launchable_test_spec_report' >> $GITHUB_OUTPUT
+        echo stdout_report_path="launchable_stdout.log" >> $GITHUB_OUTPUT
+        echo stderr_report_path="launchable_stderr.log" >> $GITHUB_OUTPUT
+      if: steps.enable-launchable.outputs.enable-launchable
+
+    - name: Set environment variables for Launchable
+      shell: bash
+      run: | # zizmor: ignore[github-env]
+        : # GITHUB_PULL_REQUEST_URL are used for commenting test reports in Launchable Github App.
+        : # https://github.com/launchableinc/cli/blob/v1.80.1/launchable/utils/link.py#L42
+        echo "GITHUB_PULL_REQUEST_URL=${INPUT_PR_HTML_URL}" >> $GITHUB_ENV
+        : # The following envs are necessary in Launchable tokenless authentication.
+        : # https://github.com/launchableinc/cli/blob/v1.80.1/launchable/utils/authentication.py#L20
+        echo "LAUNCHABLE_ORGANIZATION=${INPUT_REPOSITORY_OWNER}" >> $GITHUB_ENV
+        echo "LAUNCHABLE_WORKSPACE=${INPUT_REPOSITORY_NAME}" >> $GITHUB_ENV
+        : # https://github.com/launchableinc/cli/blob/v1.80.1/launchable/utils/authentication.py#L71
+        echo "GITHUB_PR_HEAD_SHA=${INPUT_PR_HEAD_SHA}" >> $GITHUB_ENV
+        echo "LAUNCHABLE_TOKEN=${INPUT_LAUNCHABLE_TOKEN}" >> $GITHUB_ENV
+        : # To prevent a slowdown in CI, disable request retries when the Launchable server is unstable.
+        echo "LAUNCHABLE_SKIP_TIMEOUT_RETRY=1" >> $GITHUB_ENV
+        echo "LAUNCHABLE_COMMIT_TIMEOUT=1" >> $GITHUB_ENV
+      env:
+        INPUT_PR_HTML_URL: ${{ github.event.pull_request.html_url }}
+        INPUT_REPOSITORY_OWNER: ${{ github.repository_owner }}
+        INPUT_REPOSITORY_NAME: ${{ github.event.repository.name }}
+        INPUT_PR_HEAD_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
+        INPUT_LAUNCHABLE_TOKEN: ${{ inputs.launchable-token }}
+      if: steps.enable-launchable.outputs.enable-launchable
+
+    - name: Set up path
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      # Since updated PATH variable will be available in only subsequent actions, we need to add the path beforehand.
+      # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#adding-a-system-path
+      run: echo "$(python -msite --user-base)/bin" >> $GITHUB_PATH # zizmor: ignore[github-env]
+      if: >-
+        ${{
+        steps.enable-launchable.outputs.enable-launchable
+        && (startsWith(inputs.os, 'macos')
+          || endsWith(inputs.os, 'ppc64le')
+          || endsWith(inputs.os, 's390x'))
+        }}
+
+    - name: Set up Launchable
+      id: setup-launchable
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: | # zizmor: ignore[github-env]
+        set -x
+        pip install --user launchable
+        : # The build name cannot include a slash, so we replace the string here.
+        github_ref="${INPUT_GITHUB_REF}"
+        github_ref="${github_ref//\//_}"
+        : # With the --name option, we need to configure a unique identifier for this build.
+        : # To avoid setting the same build name as the CI which runs on other branches, we use the branch name here.
+        build_name="${github_ref}_${GITHUB_PR_HEAD_SHA}"
+        test_opts="${INPUT_TEST_OPTS}"
+        test_opts="${test_opts// /}"
+        test_opts="${test_opts//=/:}"
+        test_all_test_suite='test-all'
+        btest_test_suite='btest'
+        test_spec_test_suite='test-spec'
+        if [ "${INPUT_IS_YJIT}" = "true" ]; then
+          test_all_test_suite="yjit-${test_all_test_suite}"
+          btest_test_suite="yjit-${btest_test_suite}"
+          test_spec_test_suite="yjit-${test_spec_test_suite}"
+        fi
+        if [ "${INPUT_IS_ZJIT}" = "true" ]; then
+          test_all_test_suite="zjit-${test_all_test_suite}"
+          btest_test_suite="zjit-${btest_test_suite}"
+          test_spec_test_suite="zjit-${test_spec_test_suite}"
+        fi
+        # launchable_setup target var -- refers ${target} prefixed variables
+        launchable_setup() {
+          local target=$1 session
+          eval [ "\${${target}_enabled}" = "true" ] || return
+          eval local suite=\${${target}_test_suite}
+          session=$(launchable record session \
+            --build "${build_name}" \
+            --observation \
+            --flavor os="${INPUT_OS}" \
+            --flavor test_task="${INPUT_TEST_TASK}" \
+            --flavor test_opts="${test_opts}" \
+            --flavor workflow="${INPUT_WORKFLOW}" \
+            --test-suite ${suite} \
+            )
+          echo "${target}_session=${session}" >> $GITHUB_OUTPUT
+        }
+
+        launchable record build --name "${build_name}"
+        if launchable_setup test_all; then
+          echo "TESTS=${TESTS:+$TESTS }--launchable-test-reports=${test_all_report_file}" >> $GITHUB_ENV
+        fi
+        if launchable_setup btest; then
+          echo "BTESTS=${BTESTS:+$BTESTS }--launchable-test-reports=${btest_report_file}" >> $GITHUB_ENV
+        fi
+        if launchable_setup test_spec; then
+          echo "SPECOPTS=${SPECOPTS:$SPECOPTS }--launchable-test-reports=${test_spec_report_dir}" >> $GITHUB_ENV
+          echo test_spec_enabled=true >> $GITHUB_OUTPUT
+        fi
+
+        echo launchable_setup_dir=$(pwd) >> $GITHUB_OUTPUT
+      if: steps.enable-launchable.outputs.enable-launchable
+      env:
+        INPUT_GITHUB_REF: ${{ github.ref }}
+        INPUT_TEST_OPTS: ${{ inputs.test-opts }}
+        INPUT_IS_YJIT: ${{ inputs.is-yjit }}
+        INPUT_IS_ZJIT: ${{ inputs.is-zjit }}
+        INPUT_OS: ${{ inputs.os }}
+        INPUT_TEST_TASK: ${{ inputs.test-task }}
+        INPUT_WORKFLOW: ${{ github.workflow }}
+        test_all_enabled: ${{ steps.global.outputs.test_all_enabled }}
+        btest_enabled: ${{ steps.global.outputs.btest_enabled }}
+        test_spec_enabled: ${{ steps.global.outputs.test_spec_enabled }}
+        test_all_report_file: ${{ steps.global.outputs.test_all_report_file }}
+        btest_report_file: ${{ steps.global.outputs.btest_report_file }}
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+
+    - name: make test-spec report directory in build directory
+      shell: bash
+      working-directory: ${{ inputs.builddir }}
+      run: mkdir "${test_spec_report_dir}"
+      if: ${{ steps.setup-launchable.outputs.test_spec_enabled == 'true' }}
+      env:
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+
+    - name: Clean up test results in Launchable
+      uses: gacts/run-and-post-run@81b6ce503cde93862cec047c54652e45c5dca991 # v1.4.3
+      with:
+        shell: bash
+        working-directory: ${{ inputs.builddir }}
+        post: |
+          rm -f "${test_all_report_file}"
+          rm -f "${btest_report_file}"
+          rm -fr "${test_spec_report_dir}"
+          rm -f launchable_stdout.log
+          rm -f launchable_stderr.log
+      if: always() && steps.setup-launchable.outcome == 'success'
+      env:
+        test_all_report_file: ${{ steps.global.outputs.test_all_report_file }}
+        btest_report_file: ${{ steps.global.outputs.btest_report_file }}
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+
+    - name: Record test results in Launchable
+      uses: gacts/run-and-post-run@81b6ce503cde93862cec047c54652e45c5dca991 # v1.4.3
+      with:
+        shell: bash
+        working-directory: ${{ inputs.builddir }}
+        post: |
+          if [[ "${test_all_enabled}" = "true" ]]; then \
+            launchable record attachment \
+              --session "${test_all_session}" \
+              "${stdout_report_path}" \
+              "${stderr_report_path}"; \
+            launchable record tests \
+              --session "${test_all_session}" \
+              raw "${test_all_report_file}" || true; \
+          fi
+
+          if [[ "${btest_enabled}" = "true" ]]; then \
+            launchable record attachment \
+              --session "${btest_session}" \
+              "${stdout_report_path}" \
+              "${stderr_report_path}"; \
+            launchable record tests \
+              --session "${btest_session}" \
+              raw "${btest_report_file}" || true; \
+          fi
+
+          if [[ "${test_spec_enabled}" = "true" ]]; then \
+            launchable record attachment \
+              --session "${test_spec_session}" \
+              "${stdout_report_path}" \
+              "${stderr_report_path}"; \
+            launchable record tests \
+              --session "${test_spec_session}" \
+              raw ${test_spec_report_dir}/* || true; \
+          fi
+      if: ${{ always() && steps.setup-launchable.outcome == 'success' }}
+      env:
+        test_all_report_file: ${{ steps.global.outputs.test_all_report_file }}
+        btest_report_file: ${{ steps.global.outputs.btest_report_file }}
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+        test_all_enabled: ${{ steps.global.outputs.test_all_enabled }}
+        btest_enabled: ${{ steps.global.outputs.btest_enabled }}
+        test_spec_enabled: ${{ steps.global.outputs.test_spec_enabled }}
+        test_all_session: ${{ steps.setup-launchable.outputs.test_all_session }}
+        btest_session: ${{ steps.setup-launchable.outputs.btest_session }}
+        test_spec_session: ${{ steps.setup-launchable.outputs.test_spec_session }}
+        stdout_report_path: ${{ steps.global.outputs.stdout_report_path }}
+        stderr_report_path: ${{ steps.global.outputs.stderr_report_path }}
+        LAUNCHABLE_SETUP_DIR: ${{ steps.setup-launchable.outputs.launchable_setup_dir }}
diff --git a/.github/actions/make-snapshot/action.yml b/.github/actions/make-snapshot/action.yml
new file mode 100644
index 0000000000..4552f0e067
--- /dev/null
+++ b/.github/actions/make-snapshot/action.yml
@@ -0,0 +1,77 @@
+name: 'make-snapshot'
+description: 'Make snapshot tarballs'
+inputs:
+  archname:
+    description: 'archname passed to tool/make-snapshot (e.g. snapshot-master)'
+    required: true
+  version:
+    description: 'Target Version'
+    required: false
+  shallow-since:
+    description: 'git fetch --shallow-since'
+    required: true
+    default: '2018-12-25 00:00:00'
+  fetch-branch:
+    description: 'fetch branch'
+    required: false
+  srcdir:
+    description: 'srcdir for tool/make-snapshot. Empty = clone ruby/ruby into ./ruby.'
+    required: false
+    default: ''
+  upload-artifact:
+    description: 'Upload Packages and Info as workflow artifacts. Pass "false" when callers run in a matrix that would collide on artifact names.'
+    required: false
+    default: 'true'
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install libraries
+      run: |
+        set -x
+        sudo apt-get update -q || :
+        sudo apt-get install --no-install-recommends -q -y build-essential git bison autoconf ruby p7zip-full curl
+      shell: bash
+    - name: Checkout ruby/ruby for tool/make-snapshot
+      if: inputs.srcdir == ''
+      run: git clone --single-branch --depth=1 https://github.com/ruby/ruby ruby
+      shell: bash
+    - name: Fetch branches and notes (clone mode)
+      if: inputs.srcdir == ''
+      env:
+        SHALLOW_SINCE: ${{ inputs.shallow-since }}
+        FETCH_BRANCH: ${{ inputs.fetch-branch }}
+      run: |
+        set -x
+        cd ruby
+        git fetch --shallow-since="$SHALLOW_SINCE"
+        [ -n "$FETCH_BRANCH" ] && git fetch origin "+$FETCH_BRANCH:$FETCH_BRANCH"
+        git fetch origin '+refs/notes/commits:refs/notes/commits'
+        git fetch origin '+refs/notes/log-fix:refs/notes/log-fix'
+      shell: bash
+    - name: Fetch notes (local srcdir mode)
+      if: inputs.srcdir != ''
+      working-directory: ${{ inputs.srcdir }}
+      run: |
+        git fetch origin '+refs/notes/commits:refs/notes/commits' || :
+        git fetch origin '+refs/notes/log-fix:refs/notes/log-fix' || :
+      shell: bash
+    - name: Make snapshot
+      env:
+        ARCHNAME: ${{ inputs.archname }}
+        SRCDIR: ${{ inputs.srcdir }}
+        VERSION: ${{ inputs.version }}
+      run: |
+        [ -z "$SRCDIR" ] && SRCDIR=ruby
+        ruby "$SRCDIR/tool/make-snapshot" "-archname=$ARCHNAME" -srcdir="$SRCDIR" -packages=gzip,xz,zip pkg $VERSION
+      shell: bash
+    - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: Packages
+        path: pkg
+      if: ${{ inputs.upload-artifact == 'true' }}
+    - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: Info
+        path: pkg/info
+      if: ${{ inputs.upload-artifact == 'true' }}
diff --git a/.github/actions/setup/baseruby/action.yml b/.github/actions/setup/baseruby/action.yml
new file mode 100644
index 0000000000..76fe068897
--- /dev/null
+++ b/.github/actions/setup/baseruby/action.yml
@@ -0,0 +1,73 @@
+name: Setup directories etc.
+description: >-
+  Build baseruby for cross-compiling
+
+inputs:
+  srcdir:
+    required: true
+    default: ${{ github.workspace }}
+    description: >-
+      Directory of source codes.
+
+  builddir:
+    required: false
+    default: ${{ github.workspace }}/baseruby
+    description: >-
+      Where baseruby will be built.
+
+  installdir:
+    required: false
+    default: install
+    description: >-
+      The path where the baseruby will be installed to.
+      This is relative from the workspace.
+
+outputs:
+  ruby:
+    value: ${{ steps.build.outputs.installdir }}/bin/ruby
+    description: >-
+      The path of the executable baseruby.
+  dump_ast:
+    value: ${{ steps.build.outputs.installdir }}/bin/dump_ast
+    description: >-
+      The path of the executable dump_ast.
+
+runs:
+  using: composite
+
+  steps:
+    - name: Build baseruby
+      shell: bash
+      id: build
+      run: |
+        case "$installdir" in /*) ;; *) installdir="$PWD/$installdir";; esac
+        mkdir "$builddir"
+        ln -sr "$srcdir" "$builddir/.src"
+        pushd "$builddir"
+        .src/configure "--prefix=${installdir}" --disable-install-doc
+        CONFIGURE_ARGS=--with-out-ext=-test- make install
+        install dump_ast "${installdir}/bin"
+        {
+          echo "${installdir}/bin/dump_ast"
+          echo "${installdir}/.installed.list"
+          echo "${installdir}/"
+        } >> .installed.list
+        cp .installed.list "${installdir}/"
+        make distclean
+        rm .src
+        popd
+        rmdir "$builddir"
+        {
+          echo "installdir=${installdir}"
+        } | tee -a "$GITHUB_OUTPUT"
+      env:
+        srcdir: ${{ inputs.srcdir }}
+        builddir: ${{ inputs.builddir }}
+        installdir: ${{ inputs.installdir }}
+
+    - name: clean
+      uses: gacts/run-and-post-run@598d7a875d5620e0457490555b5e18e46082aa47 # v1.4.4
+      with:
+        working-directory: ${{ inputs.srcdir }}
+        post: |
+          ruby tool/rbuninstall.rb "${{ steps.build.outputs.installdir }}/.installed.list" > /dev/null
diff --git a/.github/actions/setup/directories/action.yml b/.github/actions/setup/directories/action.yml
new file mode 100644
index 0000000000..15dc097b6e
--- /dev/null
+++ b/.github/actions/setup/directories/action.yml
@@ -0,0 +1,205 @@
+name: Setup directories etc.
+description: >-
+  Set up the source code and build directories (plus some
+  environmental tweaks)
+
+inputs:
+  srcdir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Directory to (re-)checkout source codes.  This will be created
+      if absent.  If there is no `configure` file that is also
+      generated inside.
+
+  builddir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Where binaries and other generated contents go.  This will be
+      created if absent.
+
+  make-command:
+    required: false
+    type: string
+    default: 'make'
+    description: >-
+      The command of `make`.
+
+  makeup:
+    required: false
+    type: boolean
+    # Note that `default: false` evaluates to a string constant
+    # `'false'`, which is a truthy value :sigh:
+    # https://github.com/actions/runner/issues/2238
+    default: ''
+    description: >-
+      If set to true, additionally runs `make up`.
+
+  checkout:
+    required: false
+    type: boolean
+    default: true
+    description: >-
+      If set to '' (false), skip running actions/checkout. This is useful when
+      you don't want to overwrite a GitHub token that is already set up.
+
+  dummy-files:
+    required: false
+    type: boolean
+    default: ''
+    description: >-
+      If set to true, creates dummy files in build dir.
+
+  fetch-depth:
+    required: false
+    default: '1'
+    description: The depth of commit history fetched from the remote repository
+
+  clean:
+    required: false
+    type: boolean
+    default: ''
+    description: >-
+      If set to true, clean build directory.
+
+outputs: {} # nothing?
+
+runs:
+  using: composite
+
+  steps:
+    # Note that `shell: bash` works on both Windows and Linux, but not
+    # `shell: sh`.  This is because GitHub hosted Windows runners have
+    # their bash manually installed.
+    - shell: bash
+      run: |
+        mkdir -p "${INPUT_SRCDIR}"
+        mkdir -p "${INPUT_BUILDDIR}"
+      env:
+        INPUT_SRCDIR: ${{ inputs.srcdir }}
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
+
+    # Did you know that actions/checkout works without git(1)?  We are
+    # checking that here.
+    - id: which
+      shell: bash
+      run: |
+        echo "git=`command -v git`" >> "$GITHUB_OUTPUT"
+        echo "sudo=`sudo true && command -v sudo`" >> "$GITHUB_OUTPUT"
+        echo "autoreconf=`command -v autoreconf`" >> "$GITHUB_OUTPUT"
+
+    - if: steps.which.outputs.git
+      shell: bash
+      run: |
+        git config --global core.autocrlf false
+        git config --global core.eol lf
+        git config --global advice.detachedHead 0
+        git config --global init.defaultBranch garbage
+
+    - if: inputs.checkout
+      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      with:
+        path: ${{ inputs.srcdir }}
+        fetch-depth: ${{ inputs.fetch-depth }}
+        persist-credentials: false
+
+    - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+      with:
+        path: ${{ inputs.srcdir }}/.downloaded-cache
+        key: ${{ runner.os }}-${{ runner.arch }}-downloaded-cache
+
+    - if: steps.which.outputs.autoreconf
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: ./autogen.sh --install
+
+    # This is for MinGW.
+    - if: runner.os == 'Windows'
+      shell: bash
+      run: echo "GNUMAKEFLAGS=-j$((2 * NUMBER_OF_PROCESSORS))" >> $GITHUB_ENV # zizmor: ignore[github-env]
+
+    - if: runner.os == 'Linux'
+      shell: bash
+      run: echo "GNUMAKEFLAGS=-sj$((1 + $(nproc)))" >> "$GITHUB_ENV" # zizmor: ignore[github-env]
+
+    # macOS' GNU make is so old that they doesn't understand `GNUMAKEFLAGS`.
+    - if: runner.os == 'macOS'
+      shell: bash
+      run: echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> "$GITHUB_ENV" # zizmor: ignore[github-env]
+
+    - if: inputs.makeup
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: |
+        touch config.status .rbconfig.time
+        for mk in Makefile GNUmakefile; do
+          sed -f tool/prereq.status template/$mk.in > $mk
+        done
+        make up
+
+    # Cleanup, runs even on failure
+    - if: always() && inputs.makeup
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: |
+        rm -f config.status .rbconfig.time \
+          Makefile GNUmakefile uncommon.mk enc.mk noarch-fake.rb
+        rm -f prism/.time prism/util/.time
+
+    - if: steps.which.outputs.sudo
+      shell: bash
+      run: |
+        sudo chmod -R go-w /usr/share
+        chmod -v go-w $HOME $HOME/.config || :
+        declare -a dirs # -A is not supported by old bash, e.g. macos
+        SAVE_IFS="$IFS" IFS=:; set $PATH
+        for d do
+          while [ -d "$d" ]; do
+            case "$IFS${dirs[*]}$IFS" in *"$IFS$d$IFS"*) ;; *) dirs+=("$d");; esac
+            d="${d%/*}"
+          done
+        done
+        IFS="$SAVE_IFS"
+        sudo chmod -v go-w "${dirs[@]}" || :
+
+    - if: inputs.dummy-files == 'true'
+      shell: bash
+      id: dummy-files
+      working-directory: ${{ inputs.builddir }}
+      run: |
+        : Create dummy files in build dir
+        set {{a..z},{A..Z},{0..9},foo,bar,test,zzz}.rb
+        for file; do \
+          echo > $file "raise 'do not load $file'"; \
+        done
+        # drop {a..z}.rb if case-insensitive filesystem
+        grep -F A.rb a.rb > /dev/null && set "${@:27}"
+        echo clean="cd ${INPUT_BUILDDIR} && rm $*" >> $GITHUB_OUTPUT
+      env:
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
+
+    - if: inputs.clean == 'true'
+      shell: bash
+      id: clean
+      run: |
+        echo distclean="cd ${INPUT_BUILDDIR} && ${INPUT_MAKE_COMMAND} distclean" >> $GITHUB_OUTPUT
+        echo remained-files="find ${INPUT_BUILDDIR} -ls" >> $GITHUB_OUTPUT
+        [ "${INPUT_BUILDDIR}" = "${INPUT_SRCDIR}" ] ||
+        echo final="rmdir ${INPUT_BUILDDIR}" >> $GITHUB_OUTPUT
+      env:
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
+        INPUT_SRCDIR: ${{ inputs.srcdir }}
+        INPUT_MAKE_COMMAND: ${{ inputs.make-command }}
+
+    - name: clean
+      uses: gacts/run-and-post-run@598d7a875d5620e0457490555b5e18e46082aa47 # v1.4.4
+      with:
+        working-directory:
+        post: |
+          ${{ steps.dummy-files.outputs.clean }}
+          ${{ steps.clean.outputs.distclean }}
+          ${{ steps.clean.outputs.remained-files }}
+          ${{ steps.clean.outputs.final }}
+      # rmdir randomly fails due to launchable files
+      continue-on-error: true
diff --git a/.github/actions/setup/macos/action.yml b/.github/actions/setup/macos/action.yml
new file mode 100644
index 0000000000..9cd37a9b12
--- /dev/null
+++ b/.github/actions/setup/macos/action.yml
@@ -0,0 +1,29 @@
+name: Setup macOS environment
+description: >-
+  Installs necessary packages via Homebrew.
+
+inputs: {} # nothing?
+
+outputs: {} # nothing?
+
+runs:
+  using: composite
+
+  steps:
+    - name: brew
+      shell: bash
+      run: |
+        brew install --quiet jemalloc gmp libffi openssl@3 zlib autoconf automake libtool
+
+    - name: Set ENV
+      shell: bash
+      run: | # zizmor: ignore[github-env]
+        dir_config() {
+          local args=() lib var="$1"; shift
+          for lib in "$@"; do
+            args+=("--with-${lib%@*}-dir=$(brew --prefix $lib)")
+          done
+          echo "$var=${args[*]}" >> $GITHUB_ENV
+        }
+        dir_config ruby_configure_args gmp
+        dir_config CONFIGURE_ARGS openssl@3
diff --git a/.github/actions/setup/ubuntu/action.yml b/.github/actions/setup/ubuntu/action.yml
new file mode 100644
index 0000000000..5209ccc03f
--- /dev/null
+++ b/.github/actions/setup/ubuntu/action.yml
@@ -0,0 +1,72 @@
+name: Setup ubuntu environment
+description: >-
+  At the beginning there was no way but to copy & paste `apt-get`
+  everywhere.  But now that we have composite actions, it seems better
+  merge them into one.
+
+inputs:
+  arch:
+    required: false
+    default: ''
+    description: >-
+      Architecture.  Because we run this on a GitHub-hosted runner
+      acceptable value for this input is very limited.
+
+outputs:
+  arch:
+    value: ${{ steps.uname.outputs.uname }}
+    description: >-
+      Actual architecture.  This could be different from the one
+      passed to the `inputs.arch`.  For instance giving `i386` to this
+      action yields `i686`.
+
+runs:
+  using: composite
+
+  steps:
+    - id: uname
+      name: uname
+      shell: bash
+      env:
+        arch: ${{ inputs.arch }}
+      run: |
+        setarch="${arch:+setarch $arch --}"
+        # normalize `uname`
+        if uname=$(${setarch} uname -m 2> /dev/null); then
+          # `setarch` works, `$arch` is a valid architecture name.
+          echo "setarch=${setarch}" >> "$GITHUB_OUTPUT"
+        else
+          # if `setarch` failed, take the given `arch` as-is.
+          uname="${arch}"
+          setarch=""
+        fi
+        echo "uname=$uname" >> "$GITHUB_OUTPUT"
+        echo "dpkg=${uname/686/386}" >> "$GITHUB_OUTPUT"
+
+    - name: set SETARCH
+      shell: bash
+      run: echo "SETARCH=${setarch}" >> "$GITHUB_ENV" # zizmor: ignore[github-env]
+      env:
+        setarch: ${{ steps.uname.outputs.setarch }} # validated
+
+    - name: dpkg setup
+      shell: bash
+      run: sudo dpkg --add-architecture "${dpkg}"
+      # `dpkg` is valid, also `uname`.
+      if: ${{ inputs.arch }}
+      env:
+        dpkg: ${{ steps.uname.outputs.dpkg }}
+
+    - name: apt-get
+      shell: bash
+      env:
+        arch: ${{ inputs.arch && format(':{0}', steps.uname.outputs.dpkg) || '' }}
+      run: |
+        set -x
+        sudo apt-get update -qq || :
+        sudo apt-get install --no-install-recommends -qq -y -o=Dpkg::Use-Pty=0 \
+        ${arch:+cross}build-essential${arch/:/-} \
+        libssl-dev${arch} libyaml-dev${arch} libreadline6-dev${arch} \
+        zlib1g-dev${arch} libncurses5-dev${arch} libffi-dev${arch} \
+        autoconf ruby
+        sudo apt-get install -qq -y pkg-config${arch} || :
diff --git a/.github/actions/slack/action.yml b/.github/actions/slack/action.yml
new file mode 100644
index 0000000000..6f89bef11a
--- /dev/null
+++ b/.github/actions/slack/action.yml
@@ -0,0 +1,51 @@
+name: Post a message to slack
+description: >-
+  We have our ruby/action-slack webhook.  However its arguments are
+  bit verbose to be listed in every workflow files.  Better merge them
+  into one.
+
+inputs:
+  SLACK_WEBHOOK_URL:
+    required: true
+    description: >-
+      The URL to post the payload.  This is an input because it tends
+      to be stored in a secrets vault and a composite action cannot
+      look into one.
+
+  label:
+    required: false
+    description: >-
+      Human-readable description of the run, something like "DEBUG=1".
+      This need not be unique among runs.
+
+  event_name:
+    required: false
+    default: 'push'
+    description: >-
+      Target event to trigger notification. Notify only push by default.
+
+  extra_channel_id:
+    required: false
+    description: >-
+      Slack channel ID to notify besides #alerts and #alerts-emoji.
+
+outputs: {} # Nothing?
+
+runs:
+  using: composite
+
+  steps:
+    - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+      with:
+        payload: |
+          {
+            "ci": "GitHub Actions",
+            "env": "${{ github.workflow }}${{ inputs.label && format(' / {0}', inputs.label) }}",
+            "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+            "commit": "${{ github.sha }}",
+            "branch": "${{ github.ref_name }}"
+            ${{ inputs.extra_channel_id && format(', "extra_channel_id": "{0}"', inputs.extra_channel_id) }}
+          }
+      env:
+        SLACK_WEBHOOK_URL: ${{ inputs.SLACK_WEBHOOK_URL }}
+      if: ${{ github.event_name == inputs.event_name && startsWith(github.repository, 'ruby/') }}
diff --git a/.github/auto_request_review.yml b/.github/auto_request_review.yml
new file mode 100644
index 0000000000..9e20cb7459
--- /dev/null
+++ b/.github/auto_request_review.yml
@@ -0,0 +1,21 @@
+files:
+  'yjit*': [team:jit]
+  'yjit/**/*': [team:jit]
+  'yjit/src/cruby_bindings.inc.rs': []
+  'bootstraptest/test_yjit*': [team:jit]
+  'test/ruby/test_yjit*': [team:jit]
+  'zjit*': [team:jit]
+  'zjit/**/*': [team:jit]
+  'zjit/src/cruby_bindings.inc.rs': []
+  'test/ruby/test_zjit*': [team:jit]
+  'defs/jit.mk': [team:jit]
+  'tool/zjit_bisect.rb': [team:jit]
+  'doc/jit/*': [team:jit]
+  # Skip files updated by dependabot. It's noisy in notifications, and they're auto-merged anyway.
+  'yjit/Cargo.lock': []
+  'zjit/Cargo.lock': []
+  '.github/workflows/yjit-*.yml': []
+  '.github/workflows/zjit-*.yml': []
+options:
+  ignore_draft: true
+  last_files_match_only: true
diff --git a/.github/codeql/codeql-config.yml b/.github/codeql/codeql-config.yml
new file mode 100644
index 0000000000..f5d33545c1
--- /dev/null
+++ b/.github/codeql/codeql-config.yml
@@ -0,0 +1,22 @@
+paths-ignore:
+  - benchmark
+  - sample
+  - spec/ruby/command_line/fixtures
+  - spec/ruby/core/enumerable/shared/inject.rb
+  - spec/ruby/core/exception/fixtures
+  - spec/ruby/core/proc/parameters_spec.rb
+  - spec/ruby/core/proc/ruby2_keywords_spec.rb
+  - spec/ruby/core/range/reverse_each_spec.rb
+  - spec/ruby/language/fixtures
+  - spec/ruby/language/lambda_spec.rb
+  - spec/ruby/language/method_spec.rb
+  - spec/ruby/language/string_spec.rb
+  - test/error_highlight/test_error_highlight.rb
+  - test/prism/result/named_capture_test.rb
+  - test/ruby/test_call.rb
+  - test/ruby/test_signal.rb
+  - test/ruby/test_super.rb
+  - test/ruby/test_syntax.rb
+  - test/ruby/test_unicode_escape.rb
+  - test/rubygems/specifications/foo-0.0.1-x86-mswin32.gemspec
+  - trace_point.rb
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000000..57da742e5c
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,29 @@
+version: 2
+updates:
+  - package-ecosystem: 'github-actions'
+    directories:
+      - '/'
+      - '/.github/actions/slack'
+      - '/.github/actions/setup/directories'
+    schedule:
+      interval: 'daily'
+    groups:
+      github-actions:
+        patterns:
+          - "*"
+  - package-ecosystem: 'cargo'
+    directories:
+      - '/yjit'
+      - '/zjit'
+    exclude-paths:
+      - 'gc/mmtk/**'
+    schedule:
+      interval: 'monthly'
+    groups:
+      jit:
+        patterns:
+          - "*"
+  - package-ecosystem: 'vcpkg'
+    directory: '/'
+    schedule:
+      interval: 'daily'
diff --git a/.github/labeler.yml b/.github/labeler.yml
new file mode 100644
index 0000000000..f39fcec386
--- /dev/null
+++ b/.github/labeler.yml
@@ -0,0 +1,7 @@
+Documentation:
+- changed-files:
+  - all-globs-to-all-files: doc/**
+
+Backport:
+- base-branch: 'ruby_3_\d'
+- base-branch: 'ruby_4_\d'
diff --git a/.github/workflows/annocheck.yml b/.github/workflows/annocheck.yml
new file mode 100644
index 0000000000..5991165d43
--- /dev/null
+++ b/.github/workflows/annocheck.yml
@@ -0,0 +1,111 @@
+name: Annocheck
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  compile:
+    name: test-annocheck
+
+    runs-on: ubuntu-latest
+
+    container:
+      image: ghcr.io/ruby/ruby-ci-image:gcc-11
+      options: --user root
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    env:
+      CONFIGURE_TTY: never
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci rgengc
+      RUBY_TESTOPTS: >-
+        -q
+        --color=always
+        --tty=no
+      # FIXME: Drop skipping options
+      # https://bugs.ruby-lang.org/issues/18061
+      # https://sourceware.org/annobin/annobin.html/Test-pie.html
+      TEST_ANNOCHECK_OPTS: '--skip-pie --skip-gaps'
+
+    steps:
+      - run: id
+        working-directory:
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      # Minimal flags to pass the check.
+      # -g0 disables backtraces when SEGV.  Do not set that.
+      - name: Run configure
+        run: >
+          ../src/configure -C
+          --enable-debug-env
+          --disable-install-doc
+          --with-ext=-test-/cxxanyargs,+
+          --without-valgrind
+          --without-jemalloc
+          --without-gmp
+          --with-gcc="gcc-11 -fcf-protection -Wa,--generate-missing-build-notes=yes"
+          --enable-shared
+          debugflags=-ggdb3
+          optflags=-O2
+          LDFLAGS=-Wl,-z,now
+
+      - run: make showflags
+
+      - run: make
+
+      - run: make test-annocheck
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/auto_request_review.yml b/.github/workflows/auto_request_review.yml
new file mode 100644
index 0000000000..80f2517eb5
--- /dev/null
+++ b/.github/workflows/auto_request_review.yml
@@ -0,0 +1,20 @@
+name: Auto Request Review
+on:
+  pull_request_target:
+    types: [opened, ready_for_review, reopened]
+    branches: [master]
+
+permissions:
+  contents: read
+
+jobs:
+  auto-request-review:
+    name: Auto Request Review
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'ruby/ruby' && github.base_ref == 'master' }}
+    steps:
+      - name: Request review based on files changes and/or groups the author belongs to
+        uses: necojackarc/auto-request-review@035f049cb68460341ab744f19aa9f31aae685e36 # master
+        with:
+          # scope: public_repo
+          token: ${{ secrets.MATZBOT_AUTO_REQUEST_REVIEW_TOKEN }}
diff --git a/.github/workflows/auto_review_pr.yml b/.github/workflows/auto_review_pr.yml
new file mode 100644
index 0000000000..bb84a51573
--- /dev/null
+++ b/.github/workflows/auto_review_pr.yml
@@ -0,0 +1,41 @@
+name: Auto Review PR
+on:
+  pull_request_target:
+    types: [opened, ready_for_review, reopened]
+    branches: [master]
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: 'PR number to review'
+        required: true
+        type: number
+
+permissions:
+  contents: read
+
+jobs:
+  auto-review-pr:
+    name: Auto Review PR
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'ruby/ruby' && (github.base_ref == 'master' || github.event_name == 'workflow_dispatch') }}
+
+    permissions:
+      pull-requests: write
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.4'
+          bundler: none
+
+      - name: Auto Review PR
+        run: ruby tool/auto_review_pr.rb "$GITHUB_PR_NUMBER"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_PR_NUMBER: ${{ github.event.pull_request.number || github.event.inputs.pr_number }}
diff --git a/.github/workflows/baseruby.yml b/.github/workflows/baseruby.yml
new file mode 100644
index 0000000000..9e7720f659
--- /dev/null
+++ b/.github/workflows/baseruby.yml
@@ -0,0 +1,76 @@
+name: BASERUBY Check
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  baseruby:
+    name: BASERUBY
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    strategy:
+      matrix:
+        ruby:
+          - ruby-3.1
+          - ruby-3.2
+          - ruby-3.3
+
+    steps:
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          makeup: true
+
+      - run: ./configure --disable-install-doc
+
+      - run: make all
+
+      - run: make test
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.ruby }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/bundled_gems.yml b/.github/workflows/bundled_gems.yml
new file mode 100644
index 0000000000..d329ee9b4b
--- /dev/null
+++ b/.github/workflows/bundled_gems.yml
@@ -0,0 +1,186 @@
+name: bundled_gems
+
+env:
+  UPDATE_ENABLED: true
+
+on:
+  push:
+    branches: ['master']
+    paths:
+      - '.github/workflows/bundled_gems.yml'
+      - 'gems/bundled_gems'
+  pull_request:
+    branches: ['master']
+    paths:
+      - '.github/workflows/bundled_gems.yml'
+      - 'gems/bundled_gems'
+  merge_group:
+  schedule:
+    - cron: '45 6 * * *'
+  workflow_dispatch:
+
+permissions: # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  update:
+    permissions:
+      contents: write # for Git to git push
+
+    if: ${{ github.event_name != 'schedule' || github.repository == 'ruby/ruby' }}
+
+    name: update ${{ github.workflow }}
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: 4.0
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
+          checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
+
+      - name: Set ENV
+        run: |
+          echo "TODAY=$(date +%F)" >> $GITHUB_ENV
+
+      - name: Download previous gems list
+        run: |
+          mkdir -p .downloaded-cache
+          for data in bundled_gems.json default_gems.json; do
+            ln -s .downloaded-cache/$data .
+            curl --retry 5 --retry-connrefused --retry-delay 2 --retry-max-time 60 -O -R -z ./$data https://stdgems.org/$data
+          done
+
+      - name: Update bundled gems list
+        id: bundled_gems
+        run: |
+          ruby -i~ tool/update-bundled_gems.rb gems/bundled_gems >> $GITHUB_OUTPUT
+        if: ${{ env.UPDATE_ENABLED == 'true' }}
+
+      - name: Maintain updated gems list in NEWS
+        run: |
+          ruby tool/update-NEWS-gemlist.rb bundled
+          ruby tool/update-NEWS-github-release.rb --update
+        if: ${{ env.UPDATE_ENABLED == 'true' }}
+
+      - name: Check diffs
+        id: diff
+        run: |
+          news= gems=
+          git diff --color --no-ext-diff --ignore-submodules --exit-code -- NEWS.md ||
+          news=true
+          git diff --color --no-ext-diff --ignore-submodules --exit-code -- gems/bundled_gems ||
+          gems=true
+          git add -- NEWS.md gems/bundled_gems
+          echo news=$news >> $GITHUB_OUTPUT
+          echo gems=$gems >> $GITHUB_OUTPUT
+          echo update=${news:-$gems} >> $GITHUB_OUTPUT
+
+      - name: Commit
+        id: commit
+        run: |
+          git pull --ff-only origin ${GITHUB_REF#refs/heads/}
+          message="Update bundled gems list"
+          if [ -z "${gems}" ]; then
+            git commit --message="[DOC] ${message} at ${GITHUB_SHA:0:30}"
+          else
+            git commit --message="${message} as of ${TODAY}"
+          fi
+        env:
+          TODAY: ${{ steps.bundled_gems.outputs.latest_date || env.TODAY }}
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+          gems: ${{ steps.diff.outputs.gems }}
+        if: ${{ steps.diff.outputs.update }}
+
+      - name: Development revision of bundled gems
+        run: |
+          #!ruby
+          file = "gems/bundled_gems"
+
+          SECONDS_IN_DAY = 86400
+          today = Time.new("#{ENV['TODAY']}Z")
+          if !(december = today.month == 12)
+            days = 30
+          elsif (days = 26 - today.day).positive?
+            days += 4
+          else
+            puts "::info:: just after released"
+            exit
+          end
+
+          since = "#{today.year-1}-12-26"
+          ref = ENV['GITHUB_REF']
+          puts "::group::\e[94mfetching \e[1m#{file}\e[22m since \e[1m#{since}\e[22m from \e[1m#{ref}\e[m"
+          system(*%W[git fetch --shallow-since=#{since} --no-tags origin #{ref}], exception: true)
+          puts "::endgroup::"
+
+          puts "\e[94mchecking development version bundled gems older than \e[1m#{days}\e[22m days\e[m"
+          limit = today.to_i - days * SECONDS_IN_DAY
+          old = 0
+          IO.popen(%W"git blame --line-porcelain -- #{file}") do |blame|
+            while head = blame.gets("\n\t") and s = blame.gets
+              next unless (gem = s.split(/\s+|#.*/)).size > 3
+              time = head[/^committer-time \K\d+/].to_i
+              next if (d = limit - time) <= 0
+              d /= SECONDS_IN_DAY
+              line = head[/\A\h+ \d+ \K\d+/].to_i
+              level = if d < days; 'warning'; else old += 1; 'error'; end
+              d += days
+              puts "::#{level} file=#{file},line=#{line},title=Older than #{d} days::#{gem[0]} #{gem[3]}"
+            end
+          end
+          abort "::error title=Too long-standing gems::The release comes soon." if december and old.nonzero?
+        shell: ruby {0}
+        env:
+          file: ${{ steps.logs.outputs.file }}
+          days: ${{ steps.logs.outputs.days }}
+
+      - name: Install libraries
+        uses: ./.github/actions/setup/ubuntu
+        if: ${{ steps.diff.outputs.gems }}
+
+      - name: Build
+        run: |
+          ./autogen.sh
+          ./configure -C --disable-install-doc
+          make
+        if: ${{ steps.diff.outputs.gems }}
+
+      - name: Prepare bundled gems
+        run: |
+          make -s prepare-gems
+        if: ${{ steps.diff.outputs.gems }}
+
+      - name: Test bundled gems
+        run: |
+          make -s test-bundled-gems
+        timeout-minutes: 30
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+        if: ${{ steps.diff.outputs.gems }}
+
+      - name: Push
+        run: |
+          git push origin ${GITHUB_REF#refs/heads/}
+        if: >-
+          ${{
+          github.repository == 'ruby/ruby' &&
+          !startsWith(github.event_name, 'pull') &&
+          steps.commit.outcome == 'success'
+          }}
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/check_branch.yml b/.github/workflows/check_branch.yml
deleted file mode 100644
index 4a74cbd458..0000000000
--- a/.github/workflows/check_branch.yml
+++ /dev/null
@@ -1,22 +0,0 @@
-# We bidirectionally synchronize github.com/ruby/ruby.git's master branch and
-# git.ruby-lang.org/ruby.git's master branch.
-# We can use a pull request's merge button only on the master branch.
-#
-# Therefore, we require to pass this "check_branch" on all protected branches
-# to prevent us from accidentally pushing commits to GitHub directly.
-#
-# Details: https://bugs.ruby-lang.org/issues/16094
-name: pull_request
-on: [pull_request]
-jobs:
-  check_branch:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check if branch is master
-        run: |
-          if [ "$BASE_REF" != master ]; then
-            echo "Only master branch accepts a pull request, but it's '$BASE_REF'."
-            exit 1
-          fi
-        env:
-          BASE_REF: ${{ github.base_ref }}
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
new file mode 100644
index 0000000000..a120dde7e5
--- /dev/null
+++ b/.github/workflows/check_dependencies.yml
@@ -0,0 +1,61 @@
+name: Check Dependencies
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  update-deps:
+    name: Dependency checks
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+      fail-fast: true
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+        if: ${{ contains(matrix.os, 'ubuntu') }}
+
+      - uses: ./.github/actions/setup/macos
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - uses: ./.github/actions/setup/directories
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - name: Run configure
+        run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
+
+      - run: make fix-depends
+
+      - run: git diff --color --no-ext-diff --ignore-submodules --exit-code
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.os }} / Dependencies need to update
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/check_misc.yml b/.github/workflows/check_misc.yml
new file mode 100644
index 0000000000..cb1642b9e2
--- /dev/null
+++ b/.github/workflows/check_misc.yml
@@ -0,0 +1,151 @@
+name: Misc
+on: [push, pull_request, merge_group]
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  checks:
+    name: Miscellaneous checks
+
+    permissions:
+      contents: write # for Git to git push
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: head
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          makeup: true
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
+          checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
+
+      - name: Re-generate Makefiles
+        run: |
+          # config.status needs to run as a shell script
+          { echo ':&&exit'; cat tool/prereq.status; } > config.status
+          : # same as actions/setup/directories/action.yml
+          for mk in Makefile GNUmakefile; do
+            sed -f tool/prereq.status template/$mk.in > $mk
+          done
+
+      - name: Check for code styles
+        run: |
+          set -x
+          ruby tool/auto-style.rb "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA"
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.pull_request.base.sha }}
+          GITHUB_NEW_SHA: ${{ github.event.pull_request.merge_commit_sha }}
+        # Skip 'push' events because post_push.yml fixes them on push
+        if: ${{ github.repository == 'ruby/ruby' && startsWith(github.event_name, 'pull') }}
+
+      - name: Check if date in man pages is up-to-date
+        run: |
+          git fetch origin --depth=1 "${GITHUB_OLD_SHA}"
+          git diff --exit-code --name-only "${GITHUB_OLD_SHA}" HEAD -- man ||
+          make V=1 GIT=git BASERUBY=ruby update-man-date
+          git diff --color --no-ext-diff --ignore-submodules --exit-code -- man
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.pull_request.base.sha }}
+        if: ${{ startsWith(github.event_name, 'pull') }}
+
+      - name: Check for bash specific substitution in configure.ac
+        run: |
+          git grep -n '\${[A-Za-z_0-9]*/' -- configure.ac && exit 1 || :
+
+      - name: Check for header macros
+        run: |
+          fail=
+          for header in ruby/*.h; do
+            git grep -l -F -e $header -e HAVE_`echo $header | tr a-z./ A-Z__` -- . > /dev/null && continue
+            fail=1
+            echo $header
+          done
+          exit $fail
+        working-directory: include
+
+      - id: now
+        run: |
+          date +"mon=%-m"%n"day=%-d" >> $GITHUB_OUTPUT
+        env:
+          TZ: Asia/Tokyo
+
+      - id: deprecation
+        run: |
+          eval $(sed -n 's/^#define RUBY_API_VERSION_\(MAJOR\|MINOR\) /\1=/p' include/ruby/version.h)
+          if git --no-pager grep --color -o 'rb_warn_deprecated_to_remove_at('$MAJOR'\.'$MINOR',.*' -- '*.c' >&2; then
+              false
+          else
+              true
+          fi
+        continue-on-error: ${{ steps.now.outputs.mon < 12 }}
+
+      - name: Check if to generate documents
+        id: rdoc
+        run: |
+          set -- $(sed 's/#.*//;/^rdoc /!d' gems/bundled_gems)
+          { echo version=$2; echo ref=$4; } >> $GITHUB_OUTPUT
+
+      - name: Checkout rdoc
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          repository: ruby/rdoc
+          ref: ${{ steps.rdoc.outputs.ref }}
+          path: .bundle/gems/rdoc-${{ steps.rdoc.outputs.version }}
+          persist-credentials: false
+        if: ${{ steps.rdoc.outputs.ref != '' }}
+
+      - name: Generate rdoc scripts
+        run: |
+          set -x
+          gempath=$(ruby -e 'print Gem.user_dir, "/bin"')
+          PATH=$gempath:$PATH
+          gem install --user bundler
+          bundle config --local path vendor/bundle
+          bundle install --jobs 4
+          bundle exec rake generate
+        working-directory: .bundle/gems/rdoc-${{ steps.rdoc.outputs.version }}
+        if: ${{ steps.rdoc.outputs.ref != '' }}
+
+      - name: Core docs coverage
+        run: |
+          make XRUBY=ruby RDOC_DEPENDS= RBCONFIG=update-rbconfig rdoc-coverage
+
+      - name: Generate docs
+        id: docs
+        run: |
+          make XRUBY=ruby RDOC_DEPENDS= RBCONFIG=update-rbconfig HTMLOUT=html html
+          echo htmlout=ruby-html-${GITHUB_SHA:0:10} >> $GITHUB_OUTPUT
+        # Generate only when document commit/PR
+        if: >-
+          ${{false
+          || contains(github.event.head_commit.message, '[ruby/rdoc]')
+          || contains(github.event.head_commit.message, '[DOC]')
+          || contains(github.event.pull_request.title, '[DOC]')
+          || contains(github.event.pull_request.labels.*.name, 'Documentation')
+          }}
+
+      - name: Upload docs
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          path: html
+          name: ${{ steps.docs.outputs.htmlout }}
+        if: ${{ steps.docs.outcome == 'success' }}
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/check_sast.yml b/.github/workflows/check_sast.yml
new file mode 100644
index 0000000000..c8db1103ed
--- /dev/null
+++ b/.github/workflows/check_sast.yml
@@ -0,0 +1,133 @@
+name: 'Check SAST tool'
+
+on:
+  push:
+    branches: ['master']
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  schedule:
+    - cron: '0 12 * * *'
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions: # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  zizmor:
+    name: zizmor
+
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      security-events: write
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Run zizmor
+        uses: zizmorcore/zizmor-action@5f14fd08f7cf1cb1609c1e344975f152c7ee938d # v0.5.6
+        continue-on-error: true
+
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read # for github/codeql-action/init to get workflow details
+      contents: read # for actions/checkout to fetch code
+      security-events: write # for github/codeql-action/upload-sarif to send a status report
+    # CodeQL fails to run pull requests from dependabot due to missing write access to upload results.
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: cpp
+          - language: ruby
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: none
+          config-file: .github/codeql/codeql-config.yml
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          category: '/language:${{ matrix.language }}'
+          upload: False
+          output: sarif-results
+
+      - name: filter-sarif
+        uses: advanced-security/filter-sarif@2da736ff05ef065cb2894ac6892e47b5eac2c3c0 # v1.1
+        with:
+          patterns: |
+            +**/*.rb
+            -lib/uri/mailto.rb:rb/overly-large-range
+            -lib/uri/rfc3986_parser.rb:rb/overly-large-range
+            -lib/bundler/vendor/uri/lib/uri/mailto.rb:rb/overly-large-range
+            -lib/bundler/vendor/uri/lib/uri/rfc3986_parser.rb:rb/overly-large-range
+            -spec/ruby/core/regexp/timeout_spec.rb:rb/redos
+            -test/ruby/test_io.rb:rb/non-constant-kernel-open
+            -test/open-uri/test_open-uri.rb:rb/non-constant-kernel-open
+            -test/open-uri/test_ssl.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/binread_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/readlines_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/foreach_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/write_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/read_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/kernel/open_spec.rb:rb/non-constant-kernel-open
+          input: sarif-results/${{ matrix.language }}.sarif
+          output: sarif-results/${{ matrix.language }}.sarif
+        if: ${{ matrix.language == 'ruby' }}
+        continue-on-error: true
+
+      - name: filter-sarif
+        uses: advanced-security/filter-sarif@2da736ff05ef065cb2894ac6892e47b5eac2c3c0 # v1.1
+        with:
+          patterns: |
+            +**/*.c
+            +**/*.h
+          input: sarif-results/${{ matrix.language }}.sarif
+          output: sarif-results/${{ matrix.language }}.sarif
+        if: ${{ matrix.language == 'cpp' }}
+        continue-on-error: true
+
+      - name: Upload SARIF
+        uses: github/codeql-action/upload-sarif@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          sarif_file: sarif-results/${{ matrix.language }}.sarif
+        continue-on-error: true
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
new file mode 100644
index 0000000000..f747b7fd03
--- /dev/null
+++ b/.github/workflows/compilers.yml
@@ -0,0 +1,333 @@
+# Some tests depending on this name 'Compilations' via $GITHUB_WORKFLOW. Make sure to update such tests when renaming this workflow.
+name: Compilations
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+# Each job is split so that they roughly take 30min to run through.
+jobs:
+  compile-if:
+    name: 'omnibus compilations, trigger'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+    steps:
+      - run: true
+        working-directory:
+
+  compile1:
+    name: 'omnibus compilations, #1'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      # Set fetch-depth: 10 so that Launchable can receive commits information.
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - name: 'clang 22 LTO'
+        uses: './.github/actions/compilers'
+        with:
+          tag: clang-22
+          with_gcc: 'clang-22 -flto=auto'
+          optflags: '-O2'
+          enable_shared: false
+        timeout-minutes: 30
+      - { uses: './.github/actions/compilers', name: '-O0', with: { optflags: '-O0 -march=x86-64 -mtune=generic' }, timeout-minutes: 5 }
+      # - { uses: './.github/actions/compilers', name: '-O3', with: { optflags: '-O3 -march=x86-64 -mtune=generic', check: true } }
+
+  compile2:
+    name: 'omnibus compilations, #2'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - name: 'GCC 15 LTO'
+        uses: './.github/actions/compilers'
+        with:
+          tag: gcc-15
+          with_gcc: 'gcc-15 -flto=auto -ffat-lto-objects -Werror=lto-type-mismatch'
+          optflags: '-O2'
+          enable_shared: false
+        timeout-minutes: 10
+      - { uses: './.github/actions/compilers', name: 'ext/Setup', with: { static_exts: 'etc json/* */escape' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 15', with: { tag: 'gcc-15' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 14', with: { tag: 'gcc-14' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 13', with: { tag: 'gcc-13' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 12', with: { tag: 'gcc-12' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 11', with: { tag: 'gcc-11' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 10', with: { tag: 'gcc-10' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 9',  with: { tag: 'gcc-9'  }, timeout-minutes: 5 }
+
+  compile3:
+    name: 'omnibus compilations, #3'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'clang 20', with: { tag: 'clang-20' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 19', with: { tag: 'clang-19' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 18', with: { tag: 'clang-18' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 17', with: { tag: 'clang-17' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 16', with: { tag: 'clang-16' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 15', with: { tag: 'clang-15' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 14', with: { tag: 'clang-14' }, timeout-minutes: 5 }
+
+  compile4:
+    name: 'omnibus compilations, #4'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'clang 13', with: { tag: 'clang-13' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 12', with: { tag: 'clang-12' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 11', with: { tag: 'clang-11' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 10', with: { tag: 'clang-10' }, timeout-minutes: 5 }
+        # llvm-objcopy<=9 doesn't have --wildcard. It compiles, but leaves Rust symbols in libyjit.o and fail `make test-leaked-globals`.
+      - { uses: './.github/actions/compilers', name: 'clang 9',  with: { tag: 'clang-9',   append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 8',  with: { tag: 'clang-8',   append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 7',  with: { tag: 'clang-7',   append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 6',  with: { tag: 'clang-6.0', append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+
+  compile5:
+    name: 'omnibus compilations, #5'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      # -Wno-strict-prototypes is necessary with current clang-15 since
+      # older autoconf generate functions without prototype and -pedantic
+      # now implies strict-prototypes. Disabling the error but leaving the
+      # warning generates a lot of noise from use of ANYARGS in
+      # rb_define_method() and friends.
+      # See: https://github.com/llvm/llvm-project/commit/11da1b53d8cd3507959022cd790d5a7ad4573d94
+      - { uses: './.github/actions/compilers', name: 'C99',      with: { CFLAGS: '-std=c99 -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C11',   with: { CFLAGS:   '-std=c11   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C17',   with: { CFLAGS:   '-std=c17   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C23',   with: { CFLAGS:   '-std=c2x   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++98', with: { CXXFLAGS: '-std=c++98 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++11', with: { CXXFLAGS: '-std=c++11 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++14', with: { CXXFLAGS: '-std=c++14 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++17', with: { CXXFLAGS: '-std=c++17 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+
+  compile6:
+    name: 'omnibus compilations, #6'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'C++20', with: { CXXFLAGS: '-std=c++20 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++23', with: { CXXFLAGS: '-std=c++23 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++26', with: { CXXFLAGS: '-std=c++26 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'gmp',                 with: { append_configure: '--with-gmp', test_all: 'ruby/test_bignum.rb', test_spec: "/github/workspace/src/spec/ruby/core/integer" }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'jemalloc',            with: { append_configure: '--with-jemalloc' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'valgrind',            with: { append_configure: '--with-valgrind' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'coroutine=ucontext',  with: { append_configure: '--with-coroutine=ucontext' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'coroutine=pthread',   with: { append_configure: '--with-coroutine=pthread' }, timeout-minutes: 5 }
+
+  compile7:
+    name: 'omnibus compilations, #7'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'disable-jit',         with: { append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-yjit',        with: { append_configure: '--disable-yjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-zjit',        with: { append_configure: '--disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-dln',         with: { append_configure: '--disable-dln' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'enable-mkmf-verbose', with: { append_configure: '--enable-mkmf-verbose' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-rubygems',    with: { append_configure: '--disable-rubygems' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RUBY_DEVEL',          with: { append_configure: '--enable-devel' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=0',            with: { cppflags: '-DOPT_THREADED_CODE=0' }, timeout-minutes: 5 }
+
+  compile8:
+    name: 'omnibus compilations, #8'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'NDEBUG',                         with: { cppflags: '-DNDEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RUBY_DEBUG',                     with: { cppflags: '-DRUBY_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'ARRAY_DEBUG',                    with: { cppflags: '-DARRAY_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'CCAN_LIST_DEBUG',                with: { cppflags: '-DCCAN_LIST_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'CPDEBUG=-1',                     with: { cppflags: '-DCPDEBUG=-1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'ENC_DEBUG',                      with: { cppflags: '-DENC_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_DEBUG',                       with: { cppflags: '-DGC_DEBUG' }, timeout-minutes: 5 }
+
+  compile9:
+    name: 'omnibus compilations, #9'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'HASH_DEBUG',                     with: { cppflags: '-DHASH_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'ID_TABLE_DEBUG',                 with: { cppflags: '-DID_TABLE_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_DEBUG=-1',                with: { cppflags: '-DRGENGC_DEBUG=-1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'SYMBOL_DEBUG',                   with: { cppflags: '-DSYMBOL_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_CHECK_MODE',              with: { cppflags: '-DRGENGC_CHECK_MODE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'VM_CHECK_MODE',                  with: { cppflags: '-DVM_CHECK_MODE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_EMBED_CI=0',                 with: { cppflags: '-DUSE_EMBED_CI=0' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_FLONUM=0',                   with: { cppflags: '-DUSE_FLONUM=0', append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+
+  compileX:
+    name: 'omnibus compilations, #10'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'USE_LAZY_LOAD',                  with: { cppflags: '-DUSE_LAZY_LOAD' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_RUBY_DEBUG_LOG=1',           with: { cppflags: '-DUSE_RUBY_DEBUG_LOG=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_DEBUG_COUNTER',              with: { cppflags: '-DUSE_DEBUG_COUNTER=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'SHARABLE_MIDDLE_SUBSTRING',      with: { cppflags: '-DSHARABLE_MIDDLE_SUBSTRING=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'DEBUG_FIND_TIME_NUMGUESS',       with: { cppflags: '-DDEBUG_FIND_TIME_NUMGUESS' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'DEBUG_INTEGER_PACK',             with: { cppflags: '-DDEBUG_INTEGER_PACK' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=1',            with: { cppflags: '-DOPT_THREADED_CODE=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=2',            with: { cppflags: '-DOPT_THREADED_CODE=2' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 21', with: { tag: 'clang-21' }, timeout-minutes: 5 }
+
+  compileB:
+    name: 'omnibus compilations, #11'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'GC_DEBUG_STRESS_TO_CLASS',       with: { cppflags: '-DGC_DEBUG_STRESS_TO_CLASS' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_ENABLE_LAZY_SWEEP=0',         with: { cppflags: '-DGC_ENABLE_LAZY_SWEEP=0' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_PROFILE_DETAIL_MEMORY',       with: { cppflags: '-DGC_PROFILE_DETAIL_MEMORY' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_PROFILE_MORE_DETAIL',         with: { cppflags: '-DGC_PROFILE_MORE_DETAIL' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'MALLOC_ALLOCATED_SIZE_CHECK',    with: { cppflags: '-DMALLOC_ALLOCATED_SIZE_CHECK' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_ESTIMATE_OLDMALLOC',      with: { cppflags: '-DRGENGC_ESTIMATE_OLDMALLOC' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_PROFILE',                 with: { cppflags: '-DRGENGC_PROFILE' }, timeout-minutes: 5 }
+
+  compileC:
+    name: 'omnibus compilations, #12'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'VM_DEBUG_BP_CHECK',              with: { cppflags: '-DVM_DEBUG_BP_CHECK' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'VM_DEBUG_VERIFY_METHOD_CACHE',   with: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'YJIT_FORCE_ENABLE',              with: { cppflags: '-DYJIT_FORCE_ENABLE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'UNIVERSAL_PARSER',               with: { cppflags: '-DUNIVERSAL_PARSER' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 23', with: { tag: 'clang-23' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 22', with: { tag: 'clang-22' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 8',  with: { tag: 'gcc-8'  }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 7',  with: { tag: 'gcc-7'  }, timeout-minutes: 5 }
+
+  compilemax:
+    name: 'omnibus compilations, result'
+    runs-on: ubuntu-latest
+    if: ${{ always() }}
+    needs:
+      - 'compile1'
+      - 'compile2'
+      - 'compile3'
+      - 'compile4'
+      - 'compile5'
+      - 'compile6'
+      - 'compile7'
+      - 'compile8'
+      - 'compile9'
+      - 'compileX'
+      - 'compileB'
+      - 'compileC'
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - uses: ./.github/actions/slack
+        with:
+          label: 'omnibus'
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+      - run: false
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/crosscompile.yml b/.github/workflows/crosscompile.yml
new file mode 100644
index 0000000000..3ed6429a1e
--- /dev/null
+++ b/.github/workflows/crosscompile.yml
@@ -0,0 +1,123 @@
+name: Cross compile
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    name: make (${{ matrix.host }} host on ${{ matrix.build }})
+    strategy:
+      matrix:
+        include:
+          - host: aarch64-linux-gnu
+            arch: arm64
+            build: x86_64-linux-gnu
+            runs-on: ubuntu-24.04
+            file_arch: ARM aarch64
+          - host: x86_64-linux-gnu
+            arch: amd64
+            build: aarch64-linux-gnu
+            runs-on: ubuntu-24.04-arm
+            file_arch: x86-64
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    runs-on: ${{ matrix.runs-on }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Setup cross-compilation toolchain sources
+        run: |
+          native_arch=$(dpkg --print-architecture)
+          # Restrict existing sources to native arch
+          sudo sed -i '/^Architectures:/d' /etc/apt/sources.list.d/ubuntu.sources
+          sudo sed -i "/^Types:/a Architectures: ${native_arch}" /etc/apt/sources.list.d/ubuntu.sources
+          # Add cross-arch sources
+          if [ "${{ matrix.arch }}" = "arm64" ]; then
+            cross_uri="http://ports.ubuntu.com/"
+          else
+            cross_uri="http://archive.ubuntu.com/ubuntu/"
+          fi
+          printf '%s\n' \
+            "Types: deb" \
+            "URIs: ${cross_uri}" \
+            "Suites: noble noble-updates noble-security" \
+            "Components: main universe" \
+            "Architectures: ${{ matrix.arch }}" \
+            | sudo tee /etc/apt/sources.list.d/cross-${{ matrix.arch }}.sources
+
+      - uses: ./.github/actions/setup/ubuntu
+        with:
+          arch: ${{ matrix.arch }}
+
+      - uses: ./.github/actions/setup/baseruby
+        id: baseruby
+        with:
+          srcdir: src
+
+      - name: Run configure
+        run: >-
+          ../src/configure -C --disable-install-doc
+          --prefix=/usr
+          --build=${{ matrix.build }}
+          --host=${{ matrix.host }}
+          --with-baseruby="$baseruby"
+        env:
+          baseruby: ${{ steps.baseruby.outputs.ruby }}
+
+      - run: make
+
+      - run: make install DESTDIR=$PWD/install
+
+      - name: Verify cross-compiled binary
+        run: |
+          file install/usr/bin/ruby
+          file install/usr/bin/ruby | grep -q '${{ matrix.file_arch }}'
+
+      - uses: ./.github/actions/slack
+        with:
+          label: cross ${{ matrix.host }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/cygwin.yml b/.github/workflows/cygwin.yml
new file mode 100644
index 0000000000..f1a6f79587
--- /dev/null
+++ b/.github/workflows/cygwin.yml
@@ -0,0 +1,75 @@
+name: Cygwin
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    runs-on: windows-2022
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - run: git config --global core.autocrlf input
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Setup Cygwin
+        uses: cygwin/cygwin-install-action@711d29f3da23c9f4a1798e369a6f01198c13b11a # v6.1
+        with:
+          packages: ruby gcc-core make autoconf libtool libssl-devel libyaml-devel libffi-devel zlib-devel rubygems
+          site: |
+            https://cygwin.osuosl.org/
+
+      - name: configure
+        run: |
+          ./autogen.sh
+          ./configure --disable-install-doc
+        shell: C:\cygwin\bin\bash.EXE --noprofile --norc -e -o igncr -o pipefail {0}
+
+      - name: Extract bundled gems
+        run: |
+          make ruby -j5
+          make extract-gems
+        shell: C:\cygwin\bin\bash.EXE --noprofile --norc -e -o igncr -o pipefail {0}
+
+      - name: make all
+        timeout-minutes: 30
+        run: make -j4 V=1
+        shell: C:\cygwin\bin\bash.EXE --noprofile --norc -e -o igncr -o pipefail {0}
+
+      - uses: ./.github/actions/slack
+        with:
+          label: Cygwin
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/default_gems_list.yml b/.github/workflows/default_gems_list.yml
new file mode 100644
index 0000000000..68f2d18dd6
--- /dev/null
+++ b/.github/workflows/default_gems_list.yml
@@ -0,0 +1,99 @@
+name: Update default gems list
+on: [push, pull_request, merge_group]
+
+env:
+  UPDATE_NEWS_ENABLED: true
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  update_default_gems_list:
+    name: Update default gems list
+
+    permissions:
+      contents: write # for Git to git push
+
+    runs-on: ubuntu-latest
+
+    if: ${{ github.repository == 'ruby/ruby' }}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+
+      - id: gems
+        run: true
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          makeup: true
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
+          checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Download previous gems list
+        run: |
+          data=default_gems.json
+          mkdir -p .downloaded-cache
+          ln -s .downloaded-cache/$data .
+          curl --retry 5 --retry-connrefused --retry-delay 2 --retry-max-time 60 -O -R -z ./$data https://stdgems.org/$data
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Make default gems list
+        run: |
+          #!ruby
+          require 'rubygems'
+          $:.unshift "lib"
+          rgver = File.foreach("lib/rubygems.rb") do |line|
+            break $1 if /^\s*VERSION\s*=\s*"([^"]+)"/ =~ line
+          end
+          gems = Dir.glob("{ext,lib}/**/*.gemspec").map do |f|
+            spec = Gem::Specification.load(f)
+            "#{spec.name} #{spec.version}"
+          end.sort
+          File.open("gems/default_gems", "w") do |f|
+            f.puts "RubyGems #{rgver}"
+            f.puts gems
+          end
+        shell: ruby --disable=gems {0}
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Maintain updated gems list in NEWS
+        run: |
+          ruby tool/update-NEWS-gemlist.rb default
+        if: ${{ steps.gems.outcome == 'success' && env.UPDATE_NEWS_ENABLED == 'true' }}
+
+      - name: Check diffs
+        id: diff
+        run: |
+          git diff --color --no-ext-diff --ignore-submodules --exit-code NEWS.md ||
+          echo update=true >> $GITHUB_OUTPUT
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Commit
+        run: |
+          git pull --ff-only origin ${GITHUB_REF#refs/heads/}
+          git commit --message="Update default gems list at ${GITHUB_SHA:0:30} [ci skip]" NEWS.md
+          git push origin ${GITHUB_REF#refs/heads/}
+        env:
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+        if: >-
+          ${{
+          github.repository == 'ruby/ruby' &&
+          !startsWith(github.event_name, 'pull') &&
+          steps.diff.outputs.update
+          }}
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/dependabot_automerge.yml b/.github/workflows/dependabot_automerge.yml
new file mode 100644
index 0000000000..2e4dc8d7a2
--- /dev/null
+++ b/.github/workflows/dependabot_automerge.yml
@@ -0,0 +1,32 @@
+# from https://github.com/gofiber/swagger/blob/main/.github/workflows/dependabot_automerge.yml
+name: Dependabot auto-merge
+on:
+  pull_request:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login == 'dependabot[bot]' && github.repository == 'ruby/ruby'
+    steps:
+      - name: Dependabot metadata
+        uses: dependabot/fetch-metadata@25dd0e34f4fe68f24cc83900b1fe3fe149efef98 # v3.1.0
+        id: metadata
+
+      - name: Wait for status checks
+        uses: lewagon/wait-on-check-action@9312864dfbc9fd208e9c0417843430751c042800 # v1.7.0
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          check-regexp: 'make \(check, .*\)'
+          wait-interval: 30
+
+      - name: Auto-merge for Dependabot PRs
+        if: ${{ steps.metadata.outputs.update-type == 'version-update:semver-minor' || steps.metadata.outputs.update-type == 'version-update:semver-patch' }}
+        run: gh pr merge --auto --rebase "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.MATZBOT_DEPENDABOT_MERGE_TOKEN }}
diff --git a/.github/workflows/draft-release.yml b/.github/workflows/draft-release.yml
deleted file mode 100644
index b2249629ed..0000000000
--- a/.github/workflows/draft-release.yml
+++ /dev/null
@@ -1,163 +0,0 @@
-name: Make draft release package
-
-on:
-  push:
-    tags:
-      - 'v*'
-
-jobs:
-  build-draft-release:
-    runs-on: ubuntu-latest
-    steps:
-      - run: env | sort
-      - name: Dump GitHub context
-        env:
-          GITHUB_CONTEXT: ${{ toJson(github) }}
-        run: echo "$GITHUB_CONTEXT"
-      - name: Dump job context
-        env:
-          JOB_CONTEXT: ${{ toJson(job) }}
-        run: echo "$JOB_CONTEXT"
-      - name: Dump steps context
-        env:
-          STEPS_CONTEXT: ${{ toJson(steps) }}
-        run: echo "$STEPS_CONTEXT"
-      - name: Dump runner context
-        env:
-          RUNNER_CONTEXT: ${{ toJson(runner) }}
-        run: echo "$RUNNER_CONTEXT"
-      - name: Dump strategy context
-        env:
-          STRATEGY_CONTEXT: ${{ toJson(strategy) }}
-        run: echo "$STRATEGY_CONTEXT"
-      - name: Dump matrix context
-        env:
-          MATRIX_CONTEXT: ${{ toJson(matrix) }}
-        run: echo "$MATRIX_CONTEXT"
-      - name: Install libraries
-        run: |
-          set -x
-          sudo apt-get update -q
-          sudo apt-get install --no-install-recommends -q -y build-essential git bison autoconf ruby p7zip-full curl
-      - name: Checkout ruby/ruby for tool/make-snapshot
-        run: git clone --depth=1 https://github.com/ruby/ruby ruby
-      - name: Make pkg
-        run: |
-          set -x
-          GITHUB_REF=$(echo $GITHUB_REF | sed -e "s#/draft/#/#")
-          TARGET_VERSION=$(echo $GITHUB_REF | sed -e "s#refs/tags/v##" -e "s/_\([a-z]\)/-\1/" -e "y/_/./")
-          if ruby -e "major, minor, = '${TARGET_VERSION}'.split('.').map(&:to_i); exit(major<=2 && minor<7)"; then
-            ruby ruby/tool/make-snapshot -svn pkg ${TARGET_VERSION}
-          else
-            # e.g. refs/tags/draft/v2_7_0_preview1
-            pushd ruby
-            git fetch --shallow-since='2018-12-25 00:00:00'
-            git fetch origin "+${GITHUB_REF}:${GITHUB_REF}"
-            git fetch origin +refs/notes/commits:refs/notes/commits
-            popd
-            ruby ruby/tool/make-snapshot -srcdir=ruby pkg ${TARGET_VERSION}
-          fi
-      - name: Check pkg
-        run: |
-          set -x
-          GITHUB_REF=$(echo $GITHUB_REF | sed -e "s#/draft/#/#")
-          TARGET_VERSION=$(echo $GITHUB_REF | sed -e "s#refs/tags/v##" -e "s/_\([a-z]\)/-\1/" -e "y/_/./")
-          ls -al pkg
-          7z x pkg/ruby-${TARGET_VERSION}.zip ruby-${TARGET_VERSION}/revision.h
-          cat ruby-${TARGET_VERSION}/revision.h
-          7z l pkg/ruby-${TARGET_VERSION}.zip ruby-${TARGET_VERSION}/ChangeLog
-      - name: Upload s3
-        run: |
-          set -x
-          GITHUB_REF=$(echo $GITHUB_REF | sed -e "s#/draft/#/#")
-          TARGET_VERSION=$(echo $GITHUB_REF | sed -e "s#refs/tags/v##" -e "s/_\([a-z]\)/-\1/" -e "y/_/./")
-          for ext in .tar.gz .tar.bz2 .tar.xz .zip; do
-            aws s3 cp "pkg/ruby-${TARGET_VERSION}$ext" "s3://ftp.r-l.o/pub/tmp/ruby-${TARGET_VERSION}-draft$ext" --no-progress
-            curl -sS -X PURGE -H "Fastly-Soft-Purge:1" "https://cache.ruby-lang.org/pub/tmp/ruby-${TARGET_VERSION}-draft$ext"
-          done
-        env:
-          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-      - uses: k0kubun/action-slack@v2.0.0
-        with:
-          payload: |
-            {
-              "attachments": [{
-                title: "Draft Release ${{ github.ref }}",
-                title_link: "https://cache.ruby-lang.org/pub/tmp/",
-                "text": "${{ job.status }}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }}> ",
-                "color": "danger"
-              }]
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure()
-
-  check-draft-release:
-    needs: build-draft-release
-    runs-on: ubuntu-latest
-    steps:
-      - name: Install libraries
-        run: |
-          set -x
-          sudo apt-get update -q
-          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm5 libgdbm-dev bison- autoconf- ruby- git-
-      - name: Download draft
-        run: |
-          set -x
-          GITHUB_REF=$(echo $GITHUB_REF | sed -e "s#/draft/#/#")
-          TARGET_VERSION=$(echo $GITHUB_REF | sed -e "s#refs/tags/v##" -e "s/_\([a-z]\)/-\1/" -e "y/_/./")
-          curl -sSLO https://cache.ruby-lang.org/pub/tmp/ruby-${TARGET_VERSION}-draft.tar.xz
-      - name: Extract
-        run: |
-          set -x
-          GITHUB_REF=$(echo $GITHUB_REF | sed -e "s#/draft/#/#")
-          TARGET_VERSION=$(echo $GITHUB_REF | sed -e "s#refs/tags/v##" -e "s/_\([a-z]\)/-\1/" -e "y/_/./")
-          tar xf ruby-${TARGET_VERSION}-draft.tar.xz
-      - name: Fixed world writable dirs
-        run: |
-          chmod go-w $HOME
-          sudo chmod -R go-w /usr/share
-      - name: Set ENV
-        run: |
-          echo '##[set-env name=JOBS]'-j$((1 + $(nproc --all)))
-      - name: configure
-        run: cd ruby-*/ && ./configure
-      - name: make
-        run: cd ruby-*/ && make $JOBS
-      - name: make check
-        run: cd ruby-*/ && make $JOBS check TESTOPTS="-q --tty=no" MSPECOPT="-ff"
-      - name: make install
-        run: cd ruby-*/ && sudo make $JOBS install
-        if: always() # `make check` may fail when 2.4.x
-      - name: ruby -v
-        run: ruby -v
-        if: always() # `make check` may fail when 2.4.x
-      - uses: k0kubun/action-slack@v2.0.0
-        with:
-          payload: |
-            {
-              "attachments": [{
-                title: "Check Draft Release ${{ github.ref }}",
-                title_link: "https://cache.ruby-lang.org/pub/tmp/",
-                "text": "${{ job.status }}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} check-draft-release>",
-                "color": "danger"
-              }]
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure()
-      - uses: k0kubun/action-slack@v2.0.0
-        with:
-          payload: |
-            {
-              "attachments": [{
-                title: "Check Draft Release ${{ github.ref }}",
-                title_link: "https://cache.ruby-lang.org/pub/tmp/",
-                "text": "${{ job.status }}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} check-draft-release>",
-                "color": "good"
-              }]
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: success()
diff --git a/.github/workflows/labeler.yml b/.github/workflows/labeler.yml
new file mode 100644
index 0000000000..d0a8024b05
--- /dev/null
+++ b/.github/workflows/labeler.yml
@@ -0,0 +1,15 @@
+name: "Pull Request Labeler"
+on:
+- pull_request_target
+
+permissions:
+  contents: read
+
+jobs:
+  labeler:
+    permissions:
+      contents: read
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/labeler@f27b608878404679385c85cfa523b85ccb86e213 # v6.1.0
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 339cd97bca..4f1807121f 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -1,70 +1,191 @@
-name: macos
+name: macOS
 on:
   push:
-    branches:
-      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
   pull_request:
-    branches:
-      - '*'
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
 jobs:
-  latest:
-    runs-on: macos-latest
+  make:
     strategy:
       matrix:
-        test_task: [ "check", "test-bundler", "test-bundled-gems" ]
+        include:
+          - test_task: check
+            os: macos-26
+          - test_task: check
+            os: macos-15
+            configure_args: '--with-gcc=gcc-14'
+          - test_task: check
+            os: macos-26
+            configure_args: '--with-jemalloc --with-opt-dir=$(brew --prefix jemalloc)'
+          - test_task: check
+            os: macos-26
+            configure_args: '--with-gmp'
+          - test_task: test-all
+            test_opts: --repeat-count=2
+            os: macos-26
+          - test_task: test-bundler-parallel
+            os: macos-26
+          - test_task: test-bundled-gems
+            os: macos-26
+          - test_task: check
+            os: macos-15
+          - test_task: check
+            os: macos-15-intel
+          - test_task: check
+            os: macos-14
       fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    runs-on: ${{ matrix.os }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
     steps:
-      - name: Disable Firewall
-        run: |
-          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
-          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=50 https://github.com/ruby/ruby . && git reset --hard "$GITHUB_SHA"
-        if: github.event_name == 'push'
-      - name: Checkout a pull request
-        run: git clone --depth=50 "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" . && git reset --hard "$GITHUB_REV"
-        env:
-          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
-          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
-          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        if: github.event_name == 'pull_request'
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
       - name: Install libraries
+        uses: ./.github/actions/setup/macos
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          clean: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 0 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: make sure that kern.coredump=1
+        run: |
+          sysctl -n kern.coredump
+          sudo sysctl -w kern.coredump=1
+          sudo chmod -R +rwx /cores/
+
+      - name: Delete unused SDKs
+        # To free up disk space to not run out during the run
+        run: |
+          sudo rm -rf ~/.dotnet
+          sudo rm -rf /Library/Android
+          sudo rm -rf /Library/Developer/CoreSimulator
+        continue-on-error: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc ${ruby_configure_args} ${{ matrix.configure_args }}
+
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
+      - run: make
+
+      - run: make hello
+
+      - name: runirb
         run: |
-          export WAITS='5 60'
-          tool/travis_retry.sh brew update
-          tool/travis_retry.sh brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
-      - name: Set ENV
+          echo IRB::VERSION | make runirb RUNOPT="-- -f"
+
+      - name: Set test options for skipped tests
         run: |
-          echo '##[set-env name=JOBS]'-j$((1 + $(sysctl -n hw.activecpu)))
-      - run: autoconf
-      - name: configure
-        run: ./configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
-      - run: make $JOBS
-      - name: Tests
-        run: make -s ${{ matrix.test_task }} TESTOPTS="$JOBS -q --tty=no"
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.os }}
+          test-opts: ${{ matrix.test_opts }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: Set extra test options
+        run: |
+          echo "TESTS=$TESTS ${{ matrix.test_opts }}" >> $GITHUB_ENV
+          echo "RUBY_TEST_TIMEOUT_SCALE=10" >> $GITHUB_ENV # With --repeat-count=2, flaky test by timeout occurs frequently for some reason
+        if: matrix.test_opts
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          ulimit -c unlimited
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"}
+        timeout-minutes: 90
         env:
-          MSPECOPT: "-ff" # not using `-j` because sometimes `mspec -j` silently dies
-        if: matrix.test_task != 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      - name: Tests (test-bundled-gems)
-        # Remove minitest from TEST_BUNDLED_GEMS_ALLOW_FAILURES if https://github.com/seattlerb/minitest/pull/798 is resolved
-        run: make -s ${{ matrix.test_task }} TEST_BUNDLED_GEMS_ALLOW_FAILURES=minitest
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+
+      - name: make skipped tests
+        run: |
+          make -s test-all TESTS="${TESTS//-n!\//-n/}"
         env:
-          RUBY_TESTOPTS: "-q --tty=no"
-        if: matrix.test_task == 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      - name: Leaked Globals
-        run: make -s leaked-globals
-      - uses: k0kubun/action-slack@v2.0.0
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+          PRECHECK_BUNDLED_GEMS: 'no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+
+      - name: CAPI extensions
+        uses: ./.github/actions/capiext
         with:
-          payload: |
-            {
-              "attachments": [{
-                "text": "${{ job.status}}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} / ${{ matrix.test_task }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
-            }
+          builddir: build
         env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ contains(matrix.extra_checks, 'capi') }}
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.os }} / ${{ matrix.test_task }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-latest
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/mingw.yml b/.github/workflows/mingw.yml
new file mode 100644
index 0000000000..9a47e70f8c
--- /dev/null
+++ b/.github/workflows/mingw.yml
@@ -0,0 +1,246 @@
+name: MinGW
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+# Notes:
+# Actions console encoding causes issues, see test-all & test-spec steps
+#
+jobs:
+  make:
+    runs-on: windows-${{ matrix.os }}
+
+    name: ${{ github.workflow }} (${{ matrix.msystem }})
+
+    env:
+      MSYSTEM: ${{ matrix.msystem }}
+      MSYS2_ARCH: >-
+        ${{ case(
+        contains(matrix.msystem, 'arm64'), 'aarch64',
+        contains(matrix.msystem, '64'), 'x86_64',
+        'i686'
+        ) }}
+      MINGW_PACKAGE_PREFIX: >-
+        mingw-w${{
+        case(endsWith(matrix.msystem, '64'), '64', '32')
+        }}-${{ case(
+        startsWith(matrix.msystem, 'clang'), 'clang',
+        startsWith(matrix.msystem, 'ucrt'), 'ucrt',
+        'mingw'
+        ) }}-${{ case(
+        contains(matrix.msystem, 'arm64'), 'aarch64',
+        endsWith(matrix.msystem, '64'), 'x86_64',
+        'i686'
+        ) }}
+      CFLAGS: '-mtune=generic -O3 -pipe'
+      CXXFLAGS: '-mtune=generic -O3 -pipe'
+      CPPFLAGS: '-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048'
+      LDFLAGS: '-pipe'
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    strategy:
+      matrix:
+        include:
+          # To mitigate flakiness of MinGW CI, we test only one runtime that newer MSYS2 uses.
+          # Ruby 3.2 is the first Windows Ruby to use OpenSSL 3.x
+          - msystem: 'UCRT64'
+            os: 2022
+            test_task: 'check'
+            test-all-opts: '--name=!/TestObjSpace#test_reachable_objects_during_iteration/'
+          - msystem: 'CLANGARM64'
+            os: 11-arm
+            test_task: 'check'
+      fail-fast: false
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/vcpkg'))
+      )}}
+
+    steps:
+      - uses: msys2/setup-msys2@e9898307ac31d1a803454791be09ab9973336e1c # v2.31.1
+        id: msys2
+        with:
+          msystem: ${{ matrix.msystem }}
+          update: true
+          install: >-
+            git
+            make
+            ruby
+            autoconf
+            ${{ env.MINGW_PACKAGE_PREFIX }}-gcc
+            ${{ env.MINGW_PACKAGE_PREFIX }}-ragel
+            ${{ env.MINGW_PACKAGE_PREFIX }}-openssl
+            ${{ env.MINGW_PACKAGE_PREFIX }}-libyaml
+            ${{ env.MINGW_PACKAGE_PREFIX }}-libffi
+
+      - name: Set up env
+        id: setup-env
+        working-directory:
+        run: |
+          $msys2 = ${env:MSYS2_LOCATION}
+          $msystem = ${env:MSYSTEM}.ToLower()
+          echo $msys2\usr\bin $msys2\$msystem\bin |
+            Tee-Object ${env:GITHUB_PATH} -Append -Encoding utf-8
+
+          # Use the fast device for the temporary directory.
+          # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
+          # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
+          $tmp = ${env:RUNNER_TEMP}
+          echo HOME=$home TMP=$tmp TEMP=$tmp TMPDIR=$tmp |
+            Tee-Object ${env:GITHUB_ENV} -Append -Encoding utf-8
+        shell: pwsh             # cmd.exe does not strip spaces before `|`.
+        env:
+          MSYS2_LOCATION: ${{ steps.msys2.outputs.msys2-location }}
+          MSYSTEM: ${{ matrix.msystem }}
+
+      - name: Remove Strawberry Perl pkg-config
+        working-directory:
+        # `pkg-config.bat` included in Strawberry Perl is written in
+        # Perl and doesn't work when another msys2 `perl` precede its
+        # own `perl`.
+        #
+        # ```
+        # Can't find C:\Strawberry\perl\bin\pkg-config.bat on PATH, '.' not in PATH.
+        # ```
+        run: |
+          Get-Command pkg-config.bat | % { ren $_.path ($_.path + "~") }
+        shell: pwsh
+
+      - name: Misc system & package info
+        working-directory:
+        run: |
+          group() { echo ::group::$'\e[94;1m'"$*"$'\e[m'; }
+          endgroup() { echo ::endgroup::; }
+
+          group Path
+          cygpath -wa / . $(type -p cygpath bash sh)
+          endgroup
+
+          I() {
+              group $1
+              run Where type -pa $1 && { [ $# -eq 1 ] || run Version "$@"; } ||
+                  failed+=($1)
+              endgroup
+          }
+          run() { local w m=$1; shift; w="$("$@")" && show "$m" && indent "$w"; }
+          indent() { [ -z "$1" ] || echo "$1" | /bin/sed '/^$/!s/^/  /'; }
+          show() { echo $'\e[96m'"$*"$'\e[m'; }
+
+          failed=()
+
+          I gcc.exe --version
+          I ragel.exe --version
+          I make.exe --version
+          I openssl.exe version
+          I libcrypto-3-x64.dll
+          I libssl-3-x64.dll
+
+          group Packages
+          pacman -Qs $MINGW_PACKAGE_PREFIX-* | /bin/sed -n "s,local/$MINGW_PACKAGE_PREFIX-,,p"
+          endgroup
+
+          [ ${#failed[@]} -eq 0 ]
+        shell: sh
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: configure
+        run: >
+          ../src/configure --disable-install-doc --prefix=/.
+          --build=$CHOST --host=$CHOST --target=$CHOST
+        shell: sh
+        env:
+          CHOST: ${{ env.MSYS2_ARCH }}-w64-mingw32
+
+      - name: make all
+        timeout-minutes: 30
+        run: make -j4
+
+      - name: make install
+        run: make DESTDIR=../install install-nodoc
+
+      - name: Set up Launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: windows-2022
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          test-tasks: '["test", "test-all", "test-spec"]'
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: test
+        timeout-minutes: 30
+        run: make test test-tool
+        env:
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test' }}
+
+      - name: test-all
+        timeout-minutes: 45
+        run: |
+          make ${{ StartsWith(matrix.test_task, 'test/') && matrix.test_task || 'test-all' }}
+        env:
+          RUBY_TESTOPTS: >-
+            --retry --job-status=normal --show-skip --timeout-scale=1.5 -j4
+            ${{ matrix.test-all-opts }}
+            ${{ env.TESTS }}
+          BUNDLER_VERSION:
+        if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test-all' || StartsWith(matrix.test_task, 'test/') }}
+
+      - name: test-spec
+        timeout-minutes: 10
+        run: |
+          make ${{ StartsWith(matrix.test_task, 'spec/') && matrix.test_task || 'test-spec' }}
+        if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test-spec' || StartsWith(matrix.test_task, 'spec/') }}
+
+      - uses: ./src/.github/actions/slack
+        with:
+          label: ${{ matrix.msystem }} / ${{ matrix.test_task }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
+    shell: cmd
diff --git a/.github/workflows/modgc.yml b/.github/workflows/modgc.yml
new file mode 100644
index 0000000000..218127aad7
--- /dev/null
+++ b/.github/workflows/modgc.yml
@@ -0,0 +1,179 @@
+name: ModGC
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    strategy:
+      matrix:
+        gc:
+          - name: default
+          - name: mmtk
+            mmtk_build: release
+        os: [macos-26, ubuntu-latest]
+        include:
+          - test_task: check
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci
+
+    runs-on: ${{ matrix.os }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - name: Install libraries (macOS)
+        uses: ./.github/actions/setup/macos
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Install libraries (Ubuntu)
+        uses: ./.github/actions/setup/ubuntu
+        if: ${{ contains(matrix.os, 'ubuntu') }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+        if: ${{ contains(matrix.os, 'ubuntu') }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          clean: true
+          dummy-files: false
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: make sure that kern.coredump=1
+        run: |
+          sysctl -n kern.coredump
+          sudo sysctl -w kern.coredump=1
+          sudo chmod -R +rwx /cores/
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Delete unused SDKs
+        # To free up disk space to not run out during the run
+        run: |
+          sudo rm -rf ~/.dotnet
+          sudo rm -rf /Library/Android
+          sudo rm -rf /Library/Developer/CoreSimulator
+        continue-on-error: true
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Setup Ruby GC Directory
+        run: |
+          echo "MODULAR_GC_DIR=$HOME/ruby_gc" >> $GITHUB_ENV
+
+      - name: Run configure
+        env:
+          arch: ${{ matrix.arch }}
+        run: |
+          ${SETARCH} ../src/configure -C --disable-install-doc --with-modular-gc="${MODULAR_GC_DIR}" \
+          ${arch:+--target=$arch-$OSTYPE --host=$arch-$OSTYPE}
+
+      - uses: actions-rust-lang/setup-rust-toolchain@46268bd060767258de96ed93c1251119784f2ab6 # v1.16.1
+        with:
+          cache-bin: false
+      - name: Set MMTk environment variables
+        run: |
+          echo 'EXCLUDES=../src/test/.excludes-mmtk' >> $GITHUB_ENV
+          echo 'MSPECOPT=-B../src/spec/mmtk.mspec' >> $GITHUB_ENV
+        if: ${{ matrix.gc.name == 'mmtk' }}
+
+      - run: ${SETARCH} make
+
+      - name: Build Modular  GC
+        run: |
+          echo "RUBY_GC_LIBRARY=${{ matrix.gc.name }}" >> $GITHUB_ENV
+          make install-modular-gc MODULAR_GC=${{ matrix.gc.name }} MMTK_BUILD=${{ matrix.gc.mmtk_build }}
+          make distclean-modular-gc MODULAR_GC=${{ matrix.gc.name }}
+
+      - run: ${SETARCH} make hello
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.os || 'ubuntu-22.04' }}
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          ${SETARCH} make -s ${{ matrix.test_task }} \
+            ${TESTS:+TESTS="$TESTS"} \
+            ${{ !contains(matrix.test_task, 'bundle') && 'RUBYOPT=-w' || '' }}
+        timeout-minutes: ${{ matrix.gc.timeout || 40 }}
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+
+      - name: make skipped tests
+        run: |
+          ${SETARCH} make -s test-all TESTS="${TESTS//-n!\//-n/}"
+        env:
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}${{ matrix.arch }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/parse_y.yml b/.github/workflows/parse_y.yml
new file mode 100644
index 0000000000..7c26e87e57
--- /dev/null
+++ b/.github/workflows/parse_y.yml
@@ -0,0 +1,101 @@
+name: parse.y
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      matrix:
+        include:
+          - test_task: check
+          - test_task: test-bundler-parallel
+          - test_task: test-bundled-gems
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci
+      SETARCH: ${{ matrix.arch && format('setarch {0}', matrix.arch) }}
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          clean: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc cppflags=-DRUBY_DEBUG --with-parser=parse.y
+
+      - run: make
+
+      - run: make TESTRUN_SCRIPT='-renvutil -v -e "exit EnvUtil.current_parser == %[parse.y]"' run
+        env:
+          RUNOPT0: -I$(tooldir)/lib
+
+      - name: make ${{ matrix.test_task }}
+        run: make -s ${{ matrix.test_task }} RUN_OPTS="$RUN_OPTS" SPECOPTS="$SPECOPTS"
+        env:
+          RUBY_TESTOPTS: ${{ matrix.testopts }}
+          EXCLUDES: '../src/test/.excludes-parsey'
+          RUN_OPTS: ${{ matrix.run_opts || '--parser=parse.y' }}
+          SPECOPTS: ${{ matrix.specopts || '-T --parser=parse.y' }}
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.run_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/post_push.yml b/.github/workflows/post_push.yml
new file mode 100644
index 0000000000..e351c8c286
--- /dev/null
+++ b/.github/workflows/post_push.yml
@@ -0,0 +1,97 @@
+name: Post-push
+on:
+  push:
+    branches:
+      - master
+      - 'ruby_*_*'
+
+permissions:
+  contents: read
+
+jobs:
+  hooks:
+    name: Post-push hooks
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'ruby/ruby' }}
+    steps:
+      - name: Sync git.ruby-lang.org
+        id: sync-git
+        continue-on-error: true
+        run: |
+          mkdir -p ~/.ssh
+          (umask 066; printenv RUBY_GIT_SYNC_PRIVATE_KEY > ~/.ssh/id_ed25519)
+          ssh-keyscan -t ed25519 git.ruby-lang.org >> ~/.ssh/known_hosts
+          ssh -i ~/.ssh/id_ed25519 git-sync@git.ruby-lang.org "sudo -u git /home/git/git.ruby-lang.org/bin/update-ruby.sh $GITHUB_REF"
+        env:
+          GITHUB_REF: ${{ github.ref }}
+          RUBY_GIT_SYNC_PRIVATE_KEY: ${{ secrets.RUBY_GIT_SYNC_PRIVATE_KEY }}
+        if: ${{ github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/ruby_') }}
+
+      - name: Fetch changesets on bugs.ruby-lang.org
+        run: |
+          curl "https://bugs.ruby-lang.org/sys/fetch_changesets?key=${REDMINE_SYS_API_KEY}" -s --fail-with-body -w '* status: %{http_code}\n'
+        env:
+          REDMINE_SYS_API_KEY: ${{ secrets.REDMINE_SYS_API_KEY }}
+        if: ${{ github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/ruby_') }}
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          fetch-depth: 500 # for notify-slack-commits
+          token: ${{ secrets.MATZBOT_AUTO_UPDATE_TOKEN }}
+
+      - name: Notify commit to Slack
+        run: ruby tool/notify-slack-commits.rb "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" refs/heads/master
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          SLACK_WEBHOOK_URL_ALERTS: ${{ secrets.SLACK_WEBHOOK_URL_ALERTS }}
+          SLACK_WEBHOOK_URL_COMMITS: ${{ secrets.SLACK_WEBHOOK_URL_COMMITS }}
+          SLACK_WEBHOOK_URL_RUBY_JP: ${{ secrets.SLACK_WEBHOOK_URL_RUBY_JP }}
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - name: Notify commit to ruby-cvs
+        run: |
+          SENDMAIL="ssh -i ${HOME}/.ssh/id_ed25519 git-sync@git.ruby-lang.org /usr/sbin/sendmail" \
+            ruby tool/commit-email.rb . ruby-cvs@g.ruby-lang.org \
+            "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" "$GITHUB_REF" \
+            --viewer-uri "https://github.com/ruby/ruby/commit/" \
+            --error-to cvs-admin@ruby-lang.org
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          GITHUB_REF: ${{ github.ref }}
+        if: ${{ github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/ruby_') }}
+
+      - name: Auto-correct code styles
+        run: |
+          set -x
+          ruby tool/auto-style.rb "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" refs/heads/master
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+          EMAIL: svn-admin@ruby-lang.org
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - name: Push PR notes to GitHub
+        id: pr-notes
+        continue-on-error: true
+        run: ruby tool/notes-github-pr.rb "$(pwd)/.git" "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" refs/heads/master
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+          EMAIL: svn-admin@ruby-lang.org
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - name: Check for failures
+        run: exit 1
+        if: ${{ steps.sync-git.outcome == 'failure' || steps.pr-notes.outcome == 'failure' }}
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/pr-playground.yml b/.github/workflows/pr-playground.yml
new file mode 100644
index 0000000000..dc4f075a38
--- /dev/null
+++ b/.github/workflows/pr-playground.yml
@@ -0,0 +1,131 @@
+name: Post Playground link to PR
+on:
+  pull_request_target:
+    types: [labeled]
+  workflow_run:
+    workflows: ["WebAssembly"]
+    types: [completed]
+
+permissions:
+  contents: read
+  actions: read
+
+jobs:
+  post-summary:
+    name: Post Playground link
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    # Post a comment only if the PR status check is passed and the PR is labeled with `Playground`.
+    # Triggered twice: when the PR is labeled and when PR build is passed.
+    if: >-
+      ${{ false
+      || (true
+        && github.event_name == 'pull_request_target'
+        && contains(github.event.pull_request.labels.*.name, 'Playground'))
+      || (true
+        && github.event_name == 'workflow_run'
+        && github.event.workflow_run.conclusion == 'success'
+        && github.event.workflow_run.event == 'pull_request')
+      }}
+    steps:
+      - uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const fs = require('fs/promises');
+
+            const buildWorkflowPath = '.github/workflows/wasm.yml';
+            const findSuccessfuBuildRun = async (pr) => {
+              const opts = github.rest.actions.listWorkflowRunsForRepo.endpoint.merge({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                status: 'success',
+                branch: pr.head.ref,
+              });
+              const runs = await github.paginate(opts);
+              const buildRun = runs.find(run => run.path == buildWorkflowPath);
+              return buildRun;
+            }
+
+            const postComment = async (body, pr) => {
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: pr.number,
+              });
+
+              const commentOpts = { owner: context.repo.owner, repo: context.repo.repo, body: comment };
+
+              const existingComment = comments.find(comment => comment.body.startsWith(magicComment));
+              if (existingComment) {
+                core.info(`Updating existing comment: ${existingComment.html_url}`);
+                await github.rest.issues.updateComment({
+                  ...commentOpts, comment_id: existingComment.id
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  ...commentOpts, issue_number: pr.number
+                });
+              }
+            }
+
+            const derivePRNumber = async () => {
+              if (context.payload.pull_request) {
+                return context.payload.pull_request.number;
+              }
+              // Workaround for https://github.com/orgs/community/discussions/25220
+
+              const { data: { artifacts } } = await github.rest.actions.listWorkflowRunArtifacts({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                run_id: context.payload.workflow_run.id,
+              });
+              const artifact = artifacts.find(artifact => artifact.name == 'github-pr-info');
+              if (!artifact) {
+                throw new Error('Cannot find github-pr-info.txt artifact');
+              }
+
+              const { data } = await github.rest.actions.downloadArtifact({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                artifact_id: artifact.id,
+                archive_format: 'zip',
+              });
+
+              await fs.writeFile('pr-info.zip', Buffer.from(data));
+              await exec.exec('unzip', ['pr-info.zip']);
+              return await fs.readFile('github-pr-info.txt', 'utf8');
+            }
+
+            const prNumber = await derivePRNumber();
+
+            const { data: pr } = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: prNumber,
+            });
+
+            core.info(`Checking if the PR ${prNumber} is labeled with Playground...`);
+            if (!pr.labels.some(label => label.name == 'Playground')) {
+              core.info(`The PR is not labeled with Playground.`);
+              return;
+            }
+
+            core.info(`Checking if the build is successful for ${pr.head.ref} in ${pr.head.repo.owner.login}/${pr.head.repo.name}...`);
+            const buildRun = await findSuccessfuBuildRun(pr);
+            if (!buildRun) {
+              core.info(`No successful build run found for ${buildWorkflowPath} on ${pr.head.ref} yet.`);
+              return;
+            }
+            core.info(`Found a successful build run: ${buildRun.html_url}`);
+
+            const runLink = `${process.env.GITHUB_SERVER_URL}/${process.env.GITHUB_REPOSITORY}/actions/runs/${process.env.GITHUB_RUN_ID}`;
+            const magicComment = `<!-- AUTO-GENERATED-COMMENT-PR-PLAYGROUND -->`;
+            const comment = `${magicComment}
+            **Try on Playground**: https://ruby.github.io/play-ruby?run=${buildRun.id}
+            This is an automated comment by [\`pr-playground.yml\`](${runLink}) workflow.
+            `;
+            core.info(`Comment: ${comment}`);
+            await postComment(comment, pr);
+
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
new file mode 100644
index 0000000000..5d4a31d287
--- /dev/null
+++ b/.github/workflows/publish.yml
@@ -0,0 +1,114 @@
+name: Publish Ruby packages
+
+on:
+  repository_dispatch:
+    types:
+      - release
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version of the Ruby package to release'
+        required: true
+        default: '4.0.0'
+
+permissions:
+  contents: read
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: 3.3.4
+
+      - name: Store Ruby version
+        env:
+          RUBY_VERSION: ${{ github.event.client_payload.version || github.event.inputs.version }}
+        run: |
+          echo "RUBY_VERSION=${RUBY_VERSION}" >> $GITHUB_ENV
+
+      - name: Store ABI version
+        run: echo "ABI_VERSION=$(echo ${RUBY_VERSION} | cut -d '.' -f 1-2)" >> $GITHUB_ENV
+
+      - name: Copy draft package `/tmp` to `/pub` directory
+        run: tool/release.sh ${RUBY_VERSION}
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.FTP_R_L_O_AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.FTP_R_L_O_AWS_SECRET_ACCESS_KEY }}
+          AWS_DEFAULT_REGION: us-west-2
+
+      - name: Purge URLs of release package
+        run: |
+          curl -X POST \
+            -H "Fastly-Key: ${{ secrets.FASTLY_PURGE_TOKEN }}" \
+            https://api.fastly.com/purge/cache.ruby-lang.org/pub/ruby/${ABI_VERSION}/ruby-${RUBY_VERSION}.tar.gz
+          curl -X POST \
+            -H "Fastly-Key: ${{ secrets.FASTLY_PURGE_TOKEN }}" \
+            https://api.fastly.com/purge/cache.ruby-lang.org/pub/ruby/${ABI_VERSION}/ruby-${RUBY_VERSION}.tar.xz
+          curl -X POST \
+            -H "Fastly-Key: ${{ secrets.FASTLY_PURGE_TOKEN }}" \
+            https://api.fastly.com/purge/cache.ruby-lang.org/pub/ruby/${ABI_VERSION}/ruby-${RUBY_VERSION}.zip
+
+      - name: Create a release on GitHub
+        run: |
+          RELEASE_TAG=$(ruby tool/ruby-version.rb tag "${RUBY_VERSION}")
+          echo $RELEASE_TAG
+          PREVIOUS_RELEASE_TAG=$(ruby tool/ruby-version.rb previous-tag "${RUBY_VERSION}")
+          echo $PREVIOUS_RELEASE_TAG
+          tool/gen-github-release.rb $PREVIOUS_RELEASE_TAG $RELEASE_TAG --no-dry-run
+        env:
+          GITHUB_TOKEN: ${{ secrets.MATZBOT_AUTO_UPDATE_TOKEN }}
+
+      - name: Update versions index
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/actions/dispatches \
+            -d '{"event_type": "update_index"}'
+
+      - name: Build and push Docker images
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/docker-images/dispatches \
+            -d "{\"event_type\": \"build\", \"client_payload\": {\"ruby_version\": \"${RUBY_VERSION}\"}}"
+
+      - name: Build snapcraft packages
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/snap.ruby/dispatches \
+            -d "{\"event_type\": \"build\", \"client_payload\": {\"ruby_version\": \"${RUBY_VERSION}\"}}"
+
+      - name: Store the latest LTS version of OpenSSL
+        run: |
+          echo "OPENSSL_VERSION=`curl -s https://api.github.com/repos/openssl/openssl/releases | jq -r '.[].tag_name | select(startswith("openssl-3.0"))' | sort -Vr | head -n1 | cut -d'-' -f2`" >> $GITHUB_ENV
+
+      - name: Update ruby-build definition
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.RUBY_BUILD_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/rbenv/ruby-build/dispatches \
+            -d "{\"event_type\": \"update-ruby\", \"client_payload\": {\"ruby_version\": \"${RUBY_VERSION}\", \"openssl_version\": \"${OPENSSL_VERSION}\"}}"
+
+      - name: Update all-ruby definition
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/all-ruby/dispatches \
+            -d '{"event_type": "update"}'
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000000..a35bcff99a
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,21 @@
+name: Start release workflow
+on:
+  push:
+    tags:
+      - '*'
+
+permissions:
+  contents: read
+
+jobs:
+  notify:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Build release package
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/actions/dispatches \
+            -d "{\"event_type\": \"$GITHUB_REF\"}"
diff --git a/.github/workflows/rust-warnings.yml b/.github/workflows/rust-warnings.yml
new file mode 100644
index 0000000000..7ea7d0c950
--- /dev/null
+++ b/.github/workflows/rust-warnings.yml
@@ -0,0 +1,62 @@
+# Surface Rust warnings on PRs that touch any Rust code.
+# Not a required check so we never block people over new warnings
+# that might come from a new Rust version being released.
+name: Rust warnings
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    paths:
+      - '**.rs'
+      - '!**.inc.rs'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  rust-warnings:
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Install Rust
+        run: rustup default beta
+
+      - name: Rust warnings
+        shell: bash
+        run: |
+          set -eu
+          cargo check --quiet --all-features --message-format=json \
+            | jq -r 'select(.message.level | IN("warning", "error")) | .message.rendered' \
+            | tee messages.txt
+          (exit "${PIPESTATUS[0]}") && ! grep --quiet '[^[:space:]]' messages.txt
+
+      - name: "📜 `rustdoc` warnings"
+        shell: bash
+        run: |
+          set -eu
+          cargo doc --document-private-items --all --no-deps --message-format=json \
+            | jq -r 'select(.message.level | IN("warning", "error")) | .message.rendered' \
+            | tee messages.txt
+          (exit "${PIPESTATUS[0]}") && ! grep --quiet '[^[:space:]]' messages.txt
diff --git a/.github/workflows/scorecards.yml b/.github/workflows/scorecards.yml
new file mode 100644
index 0000000000..6dc4a7c6ad
--- /dev/null
+++ b/.github/workflows/scorecards.yml
@@ -0,0 +1,78 @@
+# This workflow uses actions that are not certified by GitHub. They are provided
+# by a third-party and are governed by separate terms of service, privacy
+# policy, and support documentation.
+
+name: Scorecard supply-chain security
+on:
+  # For Branch-Protection check. Only the default branch is supported. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#branch-protection
+  branch_protection_rule:
+  # To guarantee Maintained check is occasionally updated. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained
+  schedule:
+    - cron: '39 3 * * 5'
+  # push:
+  #   branches: [ "master" ]
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    # `publish_results: true` only works when run from the default branch. conditional can be removed if disabled.
+    if: github.event.repository.default_branch == github.ref_name || github.event_name == 'pull_request'
+    permissions:
+      # Needed to upload the results to code-scanning dashboard.
+      security-events: write
+      # Needed to publish results and get a badge (see publish_results below).
+      id-token: write
+      # Uncomment the permissions below if installing in a private repository.
+      # contents: read
+      # actions: read
+
+    steps:
+      - name: "Checkout code"
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: "Run analysis"
+        uses: ossf/scorecard-action@4eaacf0543bb3f2c246792bd56e8cdeffafb205a # v2.4.3
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          # (Optional) "write" PAT token. Uncomment the `repo_token` line below if:
+          # - you want to enable the Branch-Protection check on a *public* repository, or
+          # - you are installing Scorecard on a *private* repository
+          # To create the PAT, follow the steps in https://github.com/ossf/scorecard-action?tab=readme-ov-file#authentication-with-fine-grained-pat-optional.
+          # repo_token: ${{ secrets.SCORECARD_TOKEN }}
+
+          # Public repositories:
+          #   - Publish results to OpenSSF REST API for easy access by consumers
+          #   - Allows the repository to include the Scorecard badge.
+          #   - See https://github.com/ossf/scorecard-action#publishing-results.
+          # For private repositories:
+          #   - `publish_results` will always be set to `false`, regardless
+          #     of the value entered here.
+          publish_results: true
+
+          # (Optional) Uncomment file_mode if you have a .gitattributes with files marked export-ignore
+          # file_mode: git
+
+      # Upload the results as artifacts (optional). Commenting out will disable uploads of run results in SARIF
+      # format to the repository Actions tab.
+      - name: "Upload artifact"
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard (optional).
+      # Commenting out will disable upload of results to your repo's Code Scanning dashboard
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          sarif_file: results.sarif
diff --git a/.github/workflows/spec_guards.yml b/.github/workflows/spec_guards.yml
new file mode 100644
index 0000000000..39714b13a4
--- /dev/null
+++ b/.github/workflows/spec_guards.yml
@@ -0,0 +1,68 @@
+name: Rubyspec Version Guards Check
+
+on:
+  push:
+    paths:
+      - '.github/workflows/spec_guards.yml'
+      - 'spec/**'
+      - '!spec/*.md'
+  pull_request:
+    paths:
+      - '.github/workflows/spec_guards.yml'
+      - 'spec/**'
+      - '!spec/*.md'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  rubyspec:
+    name: Rubyspec
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    strategy:
+      matrix:
+        # Specs from ruby/spec should still run on all supported Ruby versions.
+        # This also ensures the needed ruby_version_is guards are there, see spec/README.md.
+        ruby:
+          - ruby-3.3
+          - ruby-3.4
+          - ruby-4.0
+      fail-fast: false
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+
+      - run: gem install webrick
+
+      - run: ruby ../mspec/bin/mspec
+        working-directory: spec/ruby
+        env:
+          CHECK_LEAKS: true
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.ruby }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/sync_default_gems.yml b/.github/workflows/sync_default_gems.yml
new file mode 100644
index 0000000000..3aaae5864f
--- /dev/null
+++ b/.github/workflows/sync_default_gems.yml
@@ -0,0 +1,80 @@
+name: Sync default gems
+
+env:
+  DEFAULT_GEM_SYNC_ENABLED: true
+
+on:
+  workflow_dispatch:
+    inputs:
+      gem:
+        required: true
+        description: 'Name of the gem to be synchronized'
+        type: string
+      before:
+        required: true
+        description: 'Gem commit SHA before sync'
+        type: string
+      after:
+        required: true
+        description: 'Gem commit SHA after sync'
+        type: string
+
+permissions:
+  contents: read
+
+jobs:
+  sync_default_gems:
+    name: Sync default gem ${{ github.event.inputs.gem }}
+
+    permissions:
+      contents: write # for Git to git push
+
+    runs-on: ubuntu-latest
+
+    if: ${{ github.repository == 'ruby/ruby' }}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        name: Check out ruby/ruby
+        with:
+          token: ${{ github.repository == 'ruby/ruby' && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.4'
+          bundler: none
+
+      - name: Run tool/sync_default_gems.rb
+        id: sync
+        run: |
+          ruby_before=$(git rev-parse HEAD)
+          set -x
+          ruby tool/sync_default_gems.rb "${gem_name}" "${gem_before}..${gem_after}"
+          if [[ "$(git rev-parse HEAD)" != "$ruby_before" ]]; then
+            echo update=true >> $GITHUB_OUTPUT
+          fi
+        env:
+          gem_name: ${{ github.event.inputs.gem }}
+          gem_before: ${{ github.event.inputs.before }}
+          gem_after: ${{ github.event.inputs.after }}
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+
+      - name: Push
+        run: |
+          git pull --rebase origin ${GITHUB_REF#refs/heads/}
+          git push origin ${GITHUB_REF#refs/heads/}
+        if: ${{ steps.sync.outputs.update && env.DEFAULT_GEM_SYNC_ENABLED == 'true' }}
+        env:
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+          label: "${{ github.event.inputs.gem }} (<https://github.com/${{ github.event.inputs.gem == 'rubygems' && 'rubygems' || 'ruby' }}/${{ github.event.inputs.gem }}/compare/${{ github.event.inputs.before }}...${{ github.event.inputs.after }}|diff>)"
+          event_name: workflow_dispatch
+          extra_channel_id: C05FPKAU743 # alerts-sync
+        if: ${{ failure() }}
diff --git a/.github/workflows/tarball-macos.yml b/.github/workflows/tarball-macos.yml
new file mode 100644
index 0000000000..0d02cf6ae1
--- /dev/null
+++ b/.github/workflows/tarball-macos.yml
@@ -0,0 +1,101 @@
+name: tarball-macos (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master, snapshot-ruby_3_3)'
+        required: true
+        type: string
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (schedule/release builds).'
+        required: false
+        type: boolean
+        default: false
+    secrets:
+      SIMPLER_ALERTS_URL:
+        required: false
+      SNAPSHOT_SLACK_WEBHOOK_URL:
+        required: false
+
+permissions:
+  contents: read
+
+jobs:
+  macos:
+    strategy:
+      matrix:
+        test_task: [check, test-bundled-gems, test-bundler-parallel]
+        os: [macos-26, macos-15, macos-14]
+        include:
+          - os: macos-15-intel
+            test_task: check
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      ARCHNAME: ${{ inputs.archname }}
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Install libraries
+        run: |
+          with_retry () {
+            "$@" || { sleep 5 && "$@"; } || { sleep 60 && "$@"; }
+          }
+          set -x
+          with_retry brew install gmp libffi openssl zlib autoconf automake libtool libyaml
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd "$ARCHNAME/" && ./configure --with-openssl-dir=$(brew --prefix openssl) --with-libyaml-dir=$(brew --prefix libyaml)
+      - name: make
+        run: cd "$ARCHNAME/" && make $JOBS
+      - name: Tests
+        run: cd "$ARCHNAME/" && make $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+          RUBY_DEBUG_TEST_NO_REMOTE: "1"
+      # leaked-globals since 2.7
+      - name: Leaked Globals
+        run: cd "$ARCHNAME/" && make -s leaked-globals
+        if: matrix.test_task == 'check'
+      - name: make install without root privilege
+        run: cd "$ARCHNAME/" && make $JOBS install DESTDIR="/tmp/destdir"
+        if: matrix.test_task == 'check'
+      - name: make install
+        run: cd "$ARCHNAME/" && sudo make $JOBS install
+        if: matrix.test_task == 'check'
+      - name: Verify installed binaries
+        run: |
+          /usr/local/bin/ruby -v
+          /usr/local/bin/gem -v
+          /usr/local/bin/bundle -v
+        if: matrix.test_task == 'check'
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout: .github/actions/slack
+          sparse-checkout-cone-mode: false
+          persist-credentials: false
+        if: ${{ failure() }}
+      - uses: ./.github/actions/slack
+        with:
+          label: "${{ matrix.os }} / ${{ matrix.test_task }}"
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+      - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ inputs.archname }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && inputs.notify-release-channel
diff --git a/.github/workflows/tarball-non-development.yml b/.github/workflows/tarball-non-development.yml
new file mode 100644
index 0000000000..db6230b301
--- /dev/null
+++ b/.github/workflows/tarball-non-development.yml
@@ -0,0 +1,87 @@
+name: tarball-non-development (reusable)
+
+on:
+  workflow_call: {}
+
+permissions:
+  contents: read
+
+jobs:
+  non_development:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { variant: default,     remove_ruby: false, configure_extra: '' }
+          - { variant: no-ruby,     remove_ruby: true,  configure_extra: '' }
+          - { variant: baseruby-no, remove_ruby: false, configure_extra: '--with-baseruby=no' }
+    runs-on: ubuntu-24.04
+    env:
+      ruby_prefix: /tmp/ruby-snapshot
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Substitute patchlevel
+        run: |
+          set -x
+          cd snapshot-*/
+          sed -i.orig 's/^\( *# *define  *RUBY_PATCHLEVEL\)  *-.*/\1 0/' version.h
+          diff -u version.h.orig version.h || :
+          rm -f version.h.orig
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev zlib1g-dev libffi-dev libgmp-dev bison- autoconf-
+      - name: Remove host ruby
+        if: matrix.remove_ruby
+        run: |
+          set -x
+          sudo apt-get purge -y -q 'ruby*' || :
+          sudo rm -rf /opt/hostedtoolcache/Ruby
+          ! command -v ruby
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd snapshot-*/ && ./configure --prefix="${ruby_prefix}" ${{ matrix.configure_extra }}
+      - name: make
+        run: cd snapshot-*/ && make $JOBS
+      - name: Leaked Globals
+        run: cd snapshot-*/ && make -s leaked-globals
+      - name: make install
+        run: cd snapshot-*/ && make $JOBS install
+      - name: Set PATH
+        run: echo "PATH=${ruby_prefix}/bin:$PATH" >> $GITHUB_ENV
+      - name: Check patchlevel
+        id: check-patchlevel
+        run: |
+          exec "${ruby_prefix}/bin/ruby" -vx "$0"
+          #!ruby
+          puts "RUBY_PATCHLEVEL=#{RUBY_PATCHLEVEL.inspect}"
+          abort unless RUBY_PATCHLEVEL >= 0
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: Check LOADPATH
+        id: check-loadpath
+        run: |
+          exec ${ruby_prefix}/bin/ruby -vx "$0"
+          #!ruby
+          paths = $:.grep(/\+/)
+          pp paths
+          abort unless paths.empty?
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: Check pathnames
+        id: check-pathnames
+        run: |
+          ! find -name '*+*' | grep +
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: result
+        run: false
+        if: ${{ contains(steps.*.outcome, 'failure') }}
diff --git a/.github/workflows/tarball-test-schedule.yml b/.github/workflows/tarball-test-schedule.yml
new file mode 100644
index 0000000000..6684b09edb
--- /dev/null
+++ b/.github/workflows/tarball-test-schedule.yml
@@ -0,0 +1,26 @@
+name: tarball-test-schedule
+on:
+  schedule:
+    - cron: '30 18 * * *' # Daily at 18:30 UTC
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  dispatch:
+    if: ${{ github.event_name != 'schedule' || github.repository == 'ruby/ruby' }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        branch:
+          - master
+          - ruby_4_0
+          - ruby_3_4
+          - ruby_3_3
+    steps:
+      - name: Trigger tarball-test on ${{ matrix.branch }}
+        run: gh workflow run tarball-test.yml --ref "$BRANCH" --repo "$GITHUB_REPOSITORY" -f notify-release-channel=true
+        env:
+          BRANCH: ${{ matrix.branch }}
+          GH_TOKEN: ${{ secrets.MATZBOT_GITHUB_ACTION_TOKEN }}
diff --git a/.github/workflows/tarball-test.yml b/.github/workflows/tarball-test.yml
new file mode 100644
index 0000000000..f75d76761a
--- /dev/null
+++ b/.github/workflows/tarball-test.yml
@@ -0,0 +1,104 @@
+name: tarball-test
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+  workflow_dispatch:
+    inputs:
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (set by tarball-test-schedule).'
+        type: boolean
+        default: false
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  tarball:
+    runs-on: ubuntu-latest
+    # Cherry-pick to maintenance branches by changing only env.BRANCH below;
+    # archname / branch-label / Materialize all derive from it.
+    env:
+      BRANCH: master
+    outputs:
+      branch: ${{ env.BRANCH }}
+      skip: ${{ steps.skipping.outputs.skip }}
+    steps:
+      - id: skipping
+        run: echo 'skip=true' >> $GITHUB_OUTPUT
+        if: >-
+          ${{(false
+          || contains(github.event.head_commit.message, '[DOC]')
+          || contains(github.event.pull_request.title, '[DOC]')
+          || contains(github.event.pull_request.labels.*.name, 'Documentation')
+          || (github.event.pull_request.user.login == 'dependabot[bot]')
+          )}}
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          fetch-depth: 1 # actions/checkout fetches all heads/tags unless > 0
+          persist-credentials: false
+      # tool/make-snapshot derives the branch name from HEAD and looks up
+      # the upstream during ChangeLog generation. Detached checkouts
+      # (pull_request, merge_group) lack a local branch with tracking, so
+      # pin one to HEAD and connect it to the matching origin ref.
+      - name: Materialize local branch
+        run: |
+          git fetch --no-tags --depth=1 origin "+refs/heads/$BASE:refs/remotes/origin/$BASE"
+          git checkout -B "$BRANCH" HEAD
+          git branch --set-upstream-to="origin/$BASE" "$BRANCH"
+        env:
+          BASE: ${{ github.base_ref || env.BRANCH }}
+      - uses: ./.github/actions/make-snapshot
+        with:
+          archname: snapshot-${{ env.BRANCH }}
+          srcdir: '.'
+
+  ubuntu:
+    needs: tarball
+    if: ${{ ! needs.tarball.outputs.skip }}
+    uses: ./.github/workflows/tarball-ubuntu.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      notify-release-channel: ${{ github.event_name == 'workflow_dispatch' && inputs.notify-release-channel || false }}
+    secrets:
+      SIMPLER_ALERTS_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+      SNAPSHOT_SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+
+  macos:
+    needs: tarball
+    if: ${{ ! needs.tarball.outputs.skip }}
+    uses: ./.github/workflows/tarball-macos.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      notify-release-channel: ${{ github.event_name == 'workflow_dispatch' && inputs.notify-release-channel || false }}
+    secrets:
+      SIMPLER_ALERTS_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+      SNAPSHOT_SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+
+  windows:
+    needs: tarball
+    if: ${{ ! needs.tarball.outputs.skip }}
+    uses: ./.github/workflows/tarball-windows.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      notify-release-channel: ${{ github.event_name == 'workflow_dispatch' && inputs.notify-release-channel || false }}
+    secrets:
+      SIMPLER_ALERTS_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+      SNAPSHOT_SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+
+  non_development:
+    needs: tarball
+    uses: ./.github/workflows/tarball-non-development.yml
diff --git a/.github/workflows/tarball-ubuntu.yml b/.github/workflows/tarball-ubuntu.yml
new file mode 100644
index 0000000000..0482db3c7f
--- /dev/null
+++ b/.github/workflows/tarball-ubuntu.yml
@@ -0,0 +1,151 @@
+name: tarball-ubuntu (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master, snapshot-ruby_3_3)'
+        required: true
+        type: string
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (schedule/release builds).'
+        required: false
+        type: boolean
+        default: false
+    secrets:
+      SIMPLER_ALERTS_URL:
+        required: false
+      SNAPSHOT_SLACK_WEBHOOK_URL:
+        required: false
+
+permissions:
+  contents: read
+
+jobs:
+  ubuntu:
+    strategy:
+      matrix:
+        test_task: [check, test-bundler-parallel, test-bundled-gems]
+        os: [ubuntu-24.04, ubuntu-22.04]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      ARCHNAME: ${{ inputs.archname }}
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev zlib1g-dev libffi-dev libgmp-dev bison- autoconf-
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.2'
+        # test-bundled-gems requires executable host ruby
+        if: matrix.test_task == 'test-bundled-gems'
+      - name: Fixed world writable dirs
+        run: |
+          mkdir -p $HOME/.local/share
+          mkdir -p $HOME/.cache/gem/specs
+          mkdir -p $HOME/.bundle/cache
+          mkdir -p $HOME/.ssh
+          chmod a-w $HOME/.bundle
+          # chmod a-w $HOME
+          # allow to write $HOME and check stats of HOME around tests (see below)
+          chmod -v a-w $HOME/.config
+          sudo chmod -R a-w /usr/share
+          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v a-w $d; done' || :
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd "$ARCHNAME/" && ./configure
+      - name: make
+        run: cd "$ARCHNAME/" && make $JOBS
+      - name: Save stats of HOME
+        run: |
+          set -euxo pipefail
+          cat >"$ARCHNAME/save-stats.rb" <<'EOF'
+          require 'pathname'
+          require 'digest'
+          out = []
+          [
+            Dir.home,
+          ].each do |dir|
+            Dir.each_child(dir) do |name|
+              pn = File.join(dir, name)
+              st = File.stat(pn)
+              if st.file?
+                content = Digest::SHA1.file(pn).hexdigest
+              elsif st.directory? && st.nlink <= 10
+                content = Dir.children(pn).sort
+              end
+              out << [pn, "%o"%st.mode, st.nlink, st.uid, st.gid, st.size, content].to_s
+            rescue
+              out << [pn, $!.inspect].to_s
+            end
+          end
+          File.open(ARGV.shift, "w") do |io|
+            io.puts out.sort
+          end
+          EOF
+          make -C "$ARCHNAME" TESTRUN_SCRIPT=save-stats.rb RUNOPT=/tmp/stat-before-tests.txt runruby
+      - name: Tests
+        run: cd "$ARCHNAME/" && make $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+      # test_sync_default_gems triggers gpg, whose agent processes leave
+      # $HOME/.gnupg around even when GNUPGHOME points elsewhere.
+      - name: Forcibly remove ~/.gnupg
+        run: rm -rf $HOME/.gnupg
+      - name: Diff stats of HOME
+        run: |
+          make -C "$ARCHNAME" TESTRUN_SCRIPT=save-stats.rb RUNOPT=/tmp/stat-after-tests.txt runruby
+          rm -f "$ARCHNAME/save-stats.rb"
+          diff -u /tmp/stat-before-tests.txt /tmp/stat-after-tests.txt
+      # leaked-globals since 2.7
+      - name: Leaked Globals
+        run: cd "$ARCHNAME/" && make -s leaked-globals
+        if: matrix.test_task == 'check'
+      - name: make install without root privilege
+        run: cd "$ARCHNAME/" && make $JOBS install DESTDIR="/tmp/destdir"
+        if: matrix.test_task == 'check'
+      - name: make install
+        run: cd "$ARCHNAME/" && sudo make $JOBS install
+        if: matrix.test_task == 'check'
+      - name: Verify installed binaries
+        run: |
+          /usr/local/bin/ruby -v
+          /usr/local/bin/gem -v
+          /usr/local/bin/bundle -v
+        if: matrix.test_task == 'check'
+      - name: Show .local
+        run: find $HOME/.local -ls
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout: .github/actions/slack
+          sparse-checkout-cone-mode: false
+          persist-credentials: false
+        if: ${{ failure() }}
+      - uses: ./.github/actions/slack
+        with:
+          label: "${{ matrix.os }} / ${{ matrix.test_task }}"
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+      - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ inputs.archname }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && inputs.notify-release-channel
diff --git a/.github/workflows/tarball-windows.yml b/.github/workflows/tarball-windows.yml
new file mode 100644
index 0000000000..a66cdf729d
--- /dev/null
+++ b/.github/workflows/tarball-windows.yml
@@ -0,0 +1,163 @@
+name: tarball-windows (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master)'
+        required: true
+        type: string
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (schedule/release builds).'
+        required: false
+        type: boolean
+        default: false
+    secrets:
+      SIMPLER_ALERTS_URL:
+        required: false
+      SNAPSHOT_SLACK_WEBHOOK_URL:
+        required: false
+
+permissions:
+  contents: read
+
+jobs:
+  windows:
+    strategy:
+      matrix:
+        include:
+          - os: '2022'
+            test_task: check
+          - os: '2025-vs2026'
+            test_task: check
+      fail-fast: false
+    runs-on: windows-${{ matrix.os }}
+    defaults:
+      run:
+        shell: cmd
+        working-directory: build
+    name: Windows ${{ matrix.os }} (${{ matrix.test_task }})
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      PATCH: C:\msys64\usr\bin\patch.exe
+      OS_VER: windows-${{ matrix.os }}
+      # see https://github.com/ruby/ruby/commit/9ff4399decef0036897d3cfb9ac2c710dea913ca
+      OPENSSL_MODULES: C:\vcpkg\installed\x64-windows\bin
+    steps:
+      - run: md build
+        working-directory:
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.2'
+          bundler: none
+          windows-toolchain: none
+
+      - uses: msys2/setup-msys2@e9898307ac31d1a803454791be09ab9973336e1c # v2.31.1
+        id: setup-msys2
+        with:
+          update: true
+          install: >-
+            patch
+      - name: patch path
+        shell: msys2 {0}
+        run: echo PATCH=$(cygpath -wa $(command -v patch)) >> $GITHUB_ENV
+        if: ${{ steps.setup-msys2.outcome == 'success' }}
+      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: C:\vcpkg\installed
+          key: ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-
+            ${{ runner.os }}-vcpkg-installed-
+      - name: Install libraries with vcpkg
+        run: |
+          vcpkg --triplet x64-windows install gmp libffi libyaml openssl zlib
+
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: 7z x pkg/*.zip
+        working-directory:
+
+      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: snapshot-*/.downloaded-cache
+          key: downloaded-cache
+
+      - name: setup env
+        # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
+        # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
+        env:
+          ARCHNAME: ${{ inputs.archname }}
+        run: |
+          set > old.env
+          call ..\%ARCHNAME%\win32\vssetup.cmd
+          set TMP=%USERPROFILE%\AppData\Local\Temp
+          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
+          set > new.env
+
+      - name: update env
+        shell: pwsh
+        run: |
+          $old = (Get-Content old.env); $new = (Get-Content new.env)
+          del *.env
+          Compare-Object $old $new |
+            Where-Object { $_.SideIndicator -eq '=>' } |
+            Select-Object -ExpandProperty InputObject |
+            Add-Content -Path $env:GITHUB_ENV
+      - name: link libraries
+        run: |
+          for %%I in (C:\vcpkg\installed\x64-windows\bin\*.dll) do (
+            mklink %%~nxI %%I
+          )
+      - name: Configure
+        env:
+          ARCHNAME: ${{ inputs.archname }}
+        run: >-
+          ../%ARCHNAME%/win32/configure.bat --disable-install-doc
+          --with-opt-dir=C:/vcpkg/installed/x64-windows
+      - run: nmake incs
+      - run: nmake extract-extlibs
+      - run: nmake
+        env:
+          YACC: win_bison
+
+      - name: ruby -v
+        run: .\ruby -v
+
+      - run: nmake test
+        timeout-minutes: 5
+
+      - run: nmake ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: -j${{env.TEST_JOBS}}
+        timeout-minutes: 70
+        continue-on-error: ${{ matrix.continue-on-error || false }}
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout: .github/actions/slack
+          sparse-checkout-cone-mode: false
+          persist-credentials: false
+        if: ${{ failure() }}
+      - uses: ./.github/actions/slack
+        with:
+          label: "${{ env.OS_VER }} / ${{ matrix.test_task }}"
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+      - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ env.OS_VER }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ inputs.archname }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && inputs.notify-release-channel
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 03e5645d8f..c887ae3811 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -1,103 +1,275 @@
-name: ubuntu
+name: Ubuntu
 on:
   push:
-    branches:
-      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
   pull_request:
-    branches:
-      - '*'
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
 jobs:
-  latest:
-    runs-on: ubuntu-latest
+  make:
     strategy:
       matrix:
-        test_task: [ "check", "test-bundler", "test-bundled-gems" ]
+        # We enumerate every job in matrix.include to save build time
+        include:
+          - test_task: check
+            configure: 'cppflags=-DVM_CHECK_MODE'
+          - test_task: check
+            arch: i686
+          - test_task: check
+            configure: '--disable-yjit'
+          - test_task: check
+            configure: '--enable-shared --enable-load-relative'
+          - test_task: test-bundler-parallel
+            timeout: 50
+          - test_task: test-bundled-gems
+          - test_task: check
+            os: ubuntu-24.04
+            extra_checks: [capi]
+          # ubuntu-24.04-arm jobs don't start on ruby/ruby as of 2025-10-29
+          #- test_task: check
+          #  os: ubuntu-24.04-arm
       fail-fast: false
-    steps:
-      - run: env | sort
-      - name: Dump GitHub context
-        env:
-          GITHUB_CONTEXT: ${{ toJson(github) }}
-        run: echo "$GITHUB_CONTEXT"
-      - name: Dump job context
-        env:
-          JOB_CONTEXT: ${{ toJson(job) }}
-        run: echo "$JOB_CONTEXT"
-      - name: Dump steps context
-        env:
-          STEPS_CONTEXT: ${{ toJson(steps) }}
-        run: echo "$STEPS_CONTEXT"
-      - name: Dump runner context
-        env:
-          RUNNER_CONTEXT: ${{ toJson(runner) }}
-        run: echo "$RUNNER_CONTEXT"
-      - name: Dump strategy context
-        env:
-          STRATEGY_CONTEXT: ${{ toJson(strategy) }}
-        run: echo "$STRATEGY_CONTEXT"
-      - name: Dump matrix context
+
+    env: &make-env
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci
+
+    runs-on: ${{ matrix.os || 'ubuntu-22.04' }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps: &make-steps
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+        with:
+          arch: ${{ matrix.arch }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+        if: >-
+          ${{ !endsWith(matrix.os, 'arm')
+          && !endsWith(matrix.os, 'ppc64le') && !endsWith(matrix.os, 's390x') }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          clean: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Run configure
         env:
-          MATRIX_CONTEXT: ${{ toJson(matrix) }}
-        run: echo "$MATRIX_CONTEXT"
+          arch: ${{ matrix.arch }}
+          configure: ${{ matrix.configure }}
+        run: >-
+          $SETARCH ../src/configure -C --disable-install-doc ${configure:- --enable-debug-env cppflags=-DRUBY_DEBUG}
+          ${arch:+--target=$arch-$OSTYPE --host=$arch-$OSTYPE}
+
+      - run: $SETARCH make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
 
-      - name: Install libraries
+      - run: $SETARCH make
+
+      - run: $SETARCH make hello
+
+      - name: runirb
         run: |
-          set -x
-          sudo sed /etc/apt/sources.list -e "s/^# deb-src/deb-src/g" -i
-          sudo apt-get update
-          sudo apt-get install ruby2.5
-          sudo apt-get build-dep ruby2.5
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=50 https://github.com/ruby/ruby . && git reset --hard "$GITHUB_SHA"
-        if: github.event_name == 'push'
-      - name: Checkout a pull request
-        run: git clone --depth=50 "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" . && git reset --hard "$GITHUB_REV"
-        env:
-          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
-          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
-          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        if: github.event_name == 'pull_request'
-      - name: Fixed world writable dirs
+          echo IRB::VERSION | $SETARCH make runirb RUNOPT="-- -f"
+
+      - name: Set test options for skipped tests
         run: |
-          chmod go-w $HOME
-          sudo chmod -R go-w /usr/share
-      - name: Set ENV
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.os || 'ubuntu-22.04' }}
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+        continue-on-error: true
+        timeout-minutes: 3
+
+      # Avoid possible test failures with the zlib applying the following patch
+      # on s390x CPU architecture.
+      # https://github.com/madler/zlib/pull/410
+      - name: Disable DFLTCC
+        run: echo "DFLTCC=0" >> $GITHUB_ENV
+        if: ${{ endsWith(matrix.os, 's390x') }}
+
+      - name: make ${{ matrix.test_task }}
         run: |
-          echo '##[set-env name=JOBS]'-j$((1 + $(nproc --all)))
-      - run: autoconf
-      - name: configure
-        run: ./configure -C --disable-install-doc
-      - run: make $JOBS
-      - name: Tests
-        run: make -s ${{ matrix.test_task }} TESTOPTS="$JOBS -q --tty=no"
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          $SETARCH make -s ${{ matrix.test_task }} \
+          ${TESTS:+TESTS="$TESTS"} \
+          ${{ !contains(matrix.test_task, 'bundle') && 'RUBYOPT=-w' || '' }}
+        timeout-minutes: ${{ matrix.timeout || 40 }}
         env:
-          MSPECOPT: "-ff" # not using `-j` because sometimes `mspec -j` silently dies
-        if: matrix.test_task != 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      - name: Tests (test-bundled-gems)
-        # Remove minitest from TEST_BUNDLED_GEMS_ALLOW_FAILURES if https://github.com/seattlerb/minitest/pull/798 is resolved
-        run: make -s ${{ matrix.test_task }} TEST_BUNDLED_GEMS_ALLOW_FAILURES=minitest
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+
+      - name: make skipped tests
+        run: |
+          $SETARCH make -s test-all TESTS="${TESTS//-n!\//-n/}"
         env:
-          RUBY_TESTOPTS: "-q --tty=no"
-        if: matrix.test_task == 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      - name: Leaked Globals
-        run: make -s leaked-globals
-      - name: Debug GitHub context
-        run: echo "$GITHUB_CONTEXT"
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+
+      - name: test-pc
+        run: |
+          DESTDIR=${RUNNER_TEMP-${TMPDIR-/tmp}}/installed
+          $SETARCH make test-pc "DESTDIR=$DESTDIR"
+
+      - name: CAPI extensions
+        uses: ./.github/actions/capiext
+        with:
+          builddir: build
+          make: '$SETARCH make'
         env:
-          GITHUB_CONTEXT: ${{ toJson(github) }}
-        if: failure() && github.event_name == 'push'
-      - uses: k0kubun/action-slack@v2.0.0
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ contains(matrix.extra_checks, 'capi') }}
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "attachments": [{
-                "text": "${{ job.status}}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} / ${{ matrix.test_task }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
-            }
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}${{ matrix.arch }}${{ matrix.os }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  make-ibm:
+    strategy:
+      matrix:
+        include:
+          - test_task: check
+            os: ubuntu-24.04-ppc64le
+          - test_task: check
+            os: ubuntu-24.04-s390x
+      fail-fast: false
+
+    env: *make-env
+
+    runs-on: ${{ matrix.os }}
+
+    if: >-
+      ${{github.repository == 'ruby/ruby'
+      && !(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps: *make-steps
+
+  # Separated from `make` job to avoid making it a required status check
+  ruby-bench:
+    strategy:
+      matrix:
+        include:
+          # Using the same setup as ZJIT jobs
+          - bench_opts: '--warmup=1 --bench=1 --excludes=shipit'
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix="$(pwd)/install"
+
+      - run: make install
+
+      - name: Checkout ruby-bench
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          repository: ruby/ruby-bench
+          persist-credentials: false
+          path: ruby-bench
+
+      # If you want to skip failing benchmark, consider using `--excludes`.
+      # e.g. `bench_opts: '--warmup=1 --bench=1 --excludes=railsbench,lobsters'`
+      - name: Run ruby-bench
+        run: ruby run_benchmarks.rb -e "ruby::../build/install/bin/ruby" ${{ matrix.bench_opts }}
+        working-directory: ruby-bench
         env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'
+          BUNDLER_VERSION: 0
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-latest
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/wasm.yml b/.github/workflows/wasm.yml
new file mode 100644
index 0000000000..f0263de5ef
--- /dev/null
+++ b/.github/workflows/wasm.yml
@@ -0,0 +1,195 @@
+name: WebAssembly
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions: # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      matrix:
+        entry:
+#         # wasmtime can't compile non-optimized Asyncified binary due to locals explosion
+#         - { name: O0-debuginfo, optflags: '-O0', debugflags: '-g', wasmoptflags: '-O1' }
+#         - { name: O1,           optflags: '-O1', debugflags: ''  , wasmoptflags: '-O1' }
+          - { name: O2, optflags: '-O2', debugflags: '', wasmoptflags: '-O2' }
+#         - { name: O3,           optflags: '-O3', debugflags: ''  , wasmoptflags: '-O3' }
+#         # -O4 is equivalent to -O3 in clang, but it's different in wasm-opt
+#         - { name: O4,           optflags: '-O3', debugflags: ''  , wasmoptflags: '-O4' }
+#         - { name: Oz,           optflags: '-Oz', debugflags: ''  , wasmoptflags: '-Oz' }
+      fail-fast: false
+
+    env:
+      RUBY_TESTOPTS: '-q --tty=no'
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      WASI_SDK_VERSION_MAJOR: 25
+      WASI_SDK_VERSION_MINOR: 0
+      BINARYEN_VERSION: 113
+      WASMTIME_VERSION: v15.0.0
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Install libraries
+        run: |
+          set -ex
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y ruby make autoconf git wget
+
+          wasi_sdk_deb="wasi-sdk-${WASI_SDK_VERSION_MAJOR}.${WASI_SDK_VERSION_MINOR}-x86_64-linux.deb"
+          wget "https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-${WASI_SDK_VERSION_MAJOR}/${wasi_sdk_deb}"
+          sudo dpkg -i "$wasi_sdk_deb"
+          rm -f "$wasi_sdk_deb"
+
+          mkdir build-sdk
+          pushd build-sdk
+
+          wasmtime_url="https://github.com/bytecodealliance/wasmtime/releases/download/${WASMTIME_VERSION}/wasmtime-${WASMTIME_VERSION}-x86_64-linux.tar.xz"
+          wget -O - "$wasmtime_url" | tar xJf -
+          sudo ln -fs "$PWD/wasmtime-${WASMTIME_VERSION}-x86_64-linux/wasmtime" /usr/local/bin/wasmtime
+
+          binaryen_tarball="binaryen-version_${BINARYEN_VERSION}-x86_64-linux.tar.gz"
+          binaryen_url="https://github.com/WebAssembly/binaryen/releases/download/version_${BINARYEN_VERSION}/${binaryen_tarball}"
+          wget -O - "$binaryen_url" | tar xfz -
+          sudo ln -fs "$PWD/binaryen-version_${BINARYEN_VERSION}/bin/wasm-opt" /usr/local/bin/wasm-opt
+        working-directory: src
+
+      - name: Set ENV
+        run: |
+          echo "WASI_SDK_PATH=/opt/wasi-sdk" >> $GITHUB_ENV
+
+      - uses: ./.github/actions/setup/baseruby
+        id: baseruby
+        with:
+          srcdir: src
+
+      - name: Download config.guess with wasi version
+        run: |
+          rm tool/config.guess tool/config.sub
+          ruby tool/downloader.rb -d tool -e gnu config.guess config.sub
+        working-directory: src
+
+      - name: Run configure
+        run: >-
+          ../src/configure
+          --host wasm32-unknown-wasi
+          --with-baseruby="${{ steps.baseruby.outputs.ruby }}"
+          --with-dump-ast="${{ steps.baseruby.outputs.dump_ast }}"
+          --with-static-linked-ext
+          --with-ext=${EXTS// /,}
+          LDFLAGS="
+          -Xlinker --stack-first
+          -Xlinker -z -Xlinker stack-size=16777216
+          "
+          optflags="${{ matrix.entry.optflags }}"
+          debugflags="${{ matrix.entry.debugflags }}"
+          wasmoptflags="${{ matrix.entry.wasmoptflags }} ${{ matrix.entry.debugflags }}"
+        env:
+          EXTS:
+            cgi/escape
+            continuation
+            coverage
+            date
+            digest
+            digest/*
+            erb/escape
+            etc
+            fcntl
+            json
+            json/*
+            objspace
+            rbconfig/sizeof
+            ripper
+            stringio
+            strscan
+
+      # miniruby may not be built when cross-compling
+      - run: make mini ruby
+
+      - run: make install DESTDIR=$PWD/../install
+      - run: tar cfz ../install.tar.gz -C ../install .
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: ruby-wasm-install
+          path: ${{ github.workspace }}/install.tar.gz
+      - name: Show Playground URL to try the build
+        run: |
+          echo "Try on Playground: https://ruby.github.io/play-ruby?run=$GITHUB_RUN_ID" >> $GITHUB_STEP_SUMMARY
+
+      - name: Run basictest
+        run: wasmtime run ./../build/miniruby --mapdir /::./ -- basictest/test.rb
+        working-directory: src
+
+      - name: Run bootstraptest (no thread)
+        run: |
+          NO_THREAD_TESTS="$(grep -L Thread -R ./bootstraptest | awk -F/ '{ print $NF }' | uniq | sed -n 's/test_\(.*\).rb/\1/p' | paste -s -d, -)"
+          ruby ./bootstraptest/runner.rb --ruby="$(which wasmtime) run $PWD/../build/ruby --mapdir /::./ -- " --verbose "--sets=$NO_THREAD_TESTS"
+        working-directory: src
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.entry.name }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+      # Workaround for https://github.com/orgs/community/discussions/25220
+      - name: Save Pull Request number
+        if: ${{ github.event_name == 'pull_request' }}
+        run: echo "${{ github.event.pull_request.number }}" >> ${{ github.workspace }}/github-pr-info.txt
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        if: ${{ github.event_name == 'pull_request' }}
+        with:
+          name: github-pr-info
+          path: ${{ github.workspace }}/github-pr-info.txt
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index cd7b98489f..03e75ad445 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -1,75 +1,217 @@
-name: windows
+name: Windows
 on:
   push:
-    branches:
-      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
   pull_request:
-    branches:
-      - '*'
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
 jobs:
-  latest:
+  make:
     strategy:
       matrix:
-        os: [windows-2016, windows-2019]
-        vs: [2017, 2019]
-        test_task: [test]
-        exclude:
-          - os: windows-2016
-            vs: 2019
-          - os: windows-2019
-            vs: 2017
+        include:
+          - os: 2022
+            test_task: check
+          - os: 2022
+            test_task: test-bundled-gems
+          - os: 2025-vs2026
+            test_task: check
+          - os: 2025-vs2026
+            test_task: test-bundled-gems
+          - os: 11-arm
+            test_task: 'btest test-basic test-tool' # check and test-spec are broken yet.
+            target: arm64
       fail-fast: false
-    runs-on: ${{ matrix.os }}
+
+    runs-on: windows-${{ matrix.os }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/vcpkg'))
+      )}}
+
+    name: Windows ${{ matrix.os }} (${{ matrix.test_task }})
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      VCPKG_DEFAULT_TRIPLET: ${{ matrix.target || 'x64' }}-windows
+
     steps:
-      - name: Install libraries with vcpkg
+      - run: md build
+        working-directory:
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          # windows-11-arm has only 3.4.1, 3.4.2, 3.4.3, head
+          ruby-version: ${{ !endsWith(matrix.os, 'arm') && '3.1' || '3.4' }}
+          bundler: none
+          windows-toolchain: none
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          make-command: nmake
+          clean: true
+
+      - name: Install tools with scoop
         run: |
-          vcpkg --triplet x64-windows install %dependencies% || (
-            sleep 4 && vcpkg --triplet x64-windows install %dependencies%
-          ) || (
-            sleep 25 && vcpkg --triplet x64-windows install %dependencies%
-          )
-        env:
-          dependencies: openssl readline zlib
-      - name: Install libraries with chocolatey
+          if ((vcpkg.exe help install) -match "manifest") { exit }
+          Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
+          iwr -useb get.scoop.sh | iex
+          Join-Path (Resolve-Path ~).Path "scoop\shims" >> $Env:GITHUB_PATH
+          scoop install vcpkg
+        shell: pwsh
+
+      - name: Restore vcpkg artifact
+        id: restore-vcpkg
+        uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: src\vcpkg_installed
+          key: windows-${{ matrix.os }}-vcpkg-${{ hashFiles('src/vcpkg.json') }}
+
+      - name: Install libraries with vcpkg
+        id: build-vcpkg
         run: |
-          choco install winflexbison3 || (
-            sleep 4 && choco install winflexbison3
-          ) || (
-            sleep 25 && choco install winflexbison3
+          git -C "%VCPKG_INSTALLATION_ROOT%" pull --quiet
+          vcpkg install
+        working-directory: src
+        if: ${{ ! steps.restore-vcpkg.outputs.cache-hit }}
+
+      - name: Save vcpkg artifact
+        uses: actions/cache/save@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: src\vcpkg_installed
+          key: windows-${{ matrix.os }}-vcpkg-${{ hashFiles('src/vcpkg.json') }}
+        if: >-
+          steps.build-vcpkg.outcome == 'success' &&
+          (  github.ref_name == 'master'
+          || startsWith(github.ref_name, 'ruby_')
+          || ( github.event.pull_request.user.login == 'dependabot[bot]'
+          &&   startsWith(github.head_ref || github.ref_name, 'dependabot/vcpkg'))
           )
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=50 https://github.com/ruby/ruby . && git reset --hard ${{ github.sha }}
-        if: github.event_name == 'push'
-      - name: Checkout a pull request
-        run: git clone --depth=50 --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} . && git reset --hard ${{ github.event.pull_request.head.sha }}
-        if: github.event_name == 'pull_request'
-      - name: configure
+
+      - name: setup env
+        # Available Ruby versions: https://github.com/actions/runner-images/blob/main/images/windows/Windows2019-Readme.md#ruby
+        # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
+        # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
         run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          win32/configure.bat --disable-install-doc --without-ext=+,dbm,gdbm --enable-bundled-libffi --with-opt-dir=C:/vcpkg/installed/x64-windows
-      - name: nmake
+          set > old.env
+          call ..\src\win32\vssetup.cmd ^
+            -arch=${{ matrix.target || 'amd64' }} ^
+            ${{ matrix.vcvars && '-vcvars_ver=' || '' }}${{ matrix.vcvars }}
+          nmake -f nul
+          set TMP=%RUNNER_TEMP%
+          set TEMP=%RUNNER_TEMP%
+          set MAKEFLAGS=l
+          set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
+          set RUBY_OPT_DIR=%GITHUB_WORKSPACE:\=/%/src/vcpkg_installed/%VCPKG_DEFAULT_TRIPLET%
+          set > new.env
+
+      - name: update env
+        shell: pwsh
         run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          set YACC=win_bison
-          nmake up
-          nmake
-      - name: nmake test
+          $old = (Get-Content old.env); $new = (Get-Content new.env)
+          del *.env
+          Compare-Object $old $new |
+            Where-Object { $_.SideIndicator -eq '=>' } |
+            Select-Object -ExpandProperty InputObject |
+            Add-Content -Path $env:GITHUB_ENV
+
+      - name: baseruby version
+        run: ruby -v
+
+      - name: compiler version
+        run: cl
+
+      - name: volume info
+        run: Get-Volume
+        shell: pwsh
+
+      # TODO: We should use `../src` instead of `D:/a/ruby/ruby/src`
+      - name: Configure
+        run: >-
+          ../src/win32/configure.bat --disable-install-doc
+          --with-opt-dir=%RUBY_OPT_DIR%
+          --with-gmp
+
+      - run: nmake prepare-vcpkg
+
+      - run: nmake incs
+
+      - run: nmake extract-extlibs
+
+      # On all other platforms, test-spec depending on extract-gems (in common.mk) is enough.
+      # But not for this Visual Studio workflow. So here we extract gems before building.
+      - run: nmake extract-gems
+
+      # windows-11-arm runner cannot run `ruby tool/file2lastrev.rb --revision.h --output=revision.h`
+      - name: make revision.h
         run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          nmake ${{ matrix.test_task }}
-        if: "!contains(github.event.head_commit.message, '[ci skip]')"
-      - uses: k0kubun/action-slack@v2.0.0
+          win32\lastrev.bat | win32\ifchange.bat --timestamp=.revision.time revision.h -
+          type revision.h
+        working-directory: src
+
+      - run: nmake
+
+      - name: Set up Launchable
+        uses: ./.github/actions/launchable/setup
         with:
-          payload: |
-            {
-              "attachments": [{
-                "text": "${{ job.status}}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} / ${{ matrix.test_task }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
-            }
+          os: windows-${{ matrix.os }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          test-task: ${{ matrix.test_task || 'check' }}
+        continue-on-error: true
+        if: ${{ matrix.test_task != 'test-bundled-gems' }}
+        timeout-minutes: 3
+
+      - run: nmake ${{ matrix.test_task || 'check' }}
         env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'
+          RUBY_TESTOPTS: -j${{ env.TEST_JOBS || 4 }}
+        timeout-minutes: 70
+
+      - uses: ./.github/actions/slack
+        with:
+          label: Windows ${{ matrix.os }} / ${{ matrix.test_task || 'check' }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: windows-2025-vs2026
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
+    shell: cmd
diff --git a/.github/workflows/wsl.yml b/.github/workflows/wsl.yml
new file mode 100644
index 0000000000..470b68fe66
--- /dev/null
+++ b/.github/workflows/wsl.yml
@@ -0,0 +1,73 @@
+name: Ubuntu on WSL
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+permissions:
+  contents: read
+
+jobs:
+  wsl:
+    runs-on: windows-2025-vs2026
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - name: Install or update WSL
+        uses: Ubuntu/WSL/.github/actions/wsl-install@main
+        with:
+          distro: Ubuntu-24.04
+
+      - name: Install dependencies
+        uses: Ubuntu/WSL/.github/actions/wsl-bash@main
+        with:
+         distro: Ubuntu-24.04
+         working-dir: /tmp/github/
+         exec: |
+            DEBIAN_FRONTEND=noninteractive sudo apt update
+            DEBIAN_FRONTEND=noninteractive sudo apt install -y ruby build-essential autoconf libssl-dev libyaml-dev zlib1g-dev libgmp-dev libffi-dev
+
+      - name: Check out the repository
+        uses: Ubuntu/WSL/.github/actions/wsl-checkout@main
+        with:
+          distro: Ubuntu-24.04
+          working-dir: /tmp/github/
+          submodules: true
+
+      - name: Build
+        uses: Ubuntu/WSL/.github/actions/wsl-bash@main
+        with:
+         distro: Ubuntu-24.04
+         working-dir: /tmp/github/
+         exec: |
+            ./autogen.sh
+            ./configure --disable-install-doc
+            make ruby -j4
+            make extract-gems
+            make -j4
+
+      - name: Test
+        uses: Ubuntu/WSL/.github/actions/wsl-bash@main
+        with:
+         distro: Ubuntu-24.04
+         working-dir: /tmp/github/
+         exec: |
+            ./ruby -v
+            # make check TESTS="-j4" MSPECOPT="-j"
diff --git a/.github/workflows/yjit-macos.yml b/.github/workflows/yjit-macos.yml
new file mode 100644
index 0000000000..e11de6bc51
--- /dev/null
+++ b/.github/workflows/yjit-macos.yml
@@ -0,0 +1,201 @@
+name: YJIT macOS
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  cargo:
+    name: cargo test
+
+    runs-on: macos-26
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - run: RUST_BACKTRACE=1 cargo test
+        working-directory: yjit
+
+      # Also compile and test with all features enabled
+      - run: RUST_BACKTRACE=1 cargo test --all-features
+        working-directory: yjit
+
+      # Check that we can build in release mode too
+      - run: cargo build --release
+        working-directory: yjit
+
+  make:
+    strategy:
+      matrix:
+        include:
+          - test_task: 'check'
+            configure: '--enable-yjit'
+            yjit_opts: '--yjit'
+          - test_task: 'check'
+            configure: '--enable-yjit=dev'
+            yjit_opts: '--yjit-call-threshold=1 --yjit-verify-ctx --yjit-code-gc'
+            specopts: '-T --yjit-call-threshold=1 -T --yjit-verify-ctx -T --yjit-code-gc'
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUN_OPTS: ${{ matrix.yjit_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
+
+    runs-on: macos-26
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - name: Install libraries
+        uses: ./.github/actions/setup/macos
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc ${{ matrix.configure }}
+
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
+      - run: make
+
+      - name: Verify that --yjit-dump-disasm works
+        run: |
+          ./miniruby --yjit-call-threshold=1 --yjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      - name: Set ENV for YJIT
+        run: |
+          echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: macos-26
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-yjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" \
+            SPECOPTS="$SPECOPTS"
+        timeout-minutes: 60
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          SYNTAX_SUGGEST_TIMEOUT: '5'
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
+
+      - name: make skipped tests
+        run: |
+          make -s test-all TESTS="${TESTS//-n!\//-n/}"
+        env:
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+          PRECHECK_BUNDLED_GEMS: 'no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }} ${{ matrix.yjit_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-latest
+    needs: [make]
+    steps:
+      - name: ${{ github.workflow }} jobs have failed
+        run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/yjit-ubuntu.yml b/.github/workflows/yjit-ubuntu.yml
new file mode 100644
index 0000000000..ab816940f4
--- /dev/null
+++ b/.github/workflows/yjit-ubuntu.yml
@@ -0,0 +1,245 @@
+name: YJIT Ubuntu
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  cargo:
+    name: cargo test
+
+    # GitHub Action's image seems to already contain a Rust 1.58.0.
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      # For now we can't run cargo test --offline because it complains about the
+      # capstone dependency, even though the dependency is optional
+      #- run: cargo test --offline
+
+      - run: RUST_BACKTRACE=1 cargo test
+        working-directory: yjit
+
+      # Also compile and test with all features enabled
+      - run: RUST_BACKTRACE=1 cargo test --all-features
+        working-directory: yjit
+
+      # Check that we can build in release mode too
+      - run: cargo build --release
+        working-directory: yjit
+
+  lint:
+    name: cargo clippy
+
+    # GitHub Action's image seems to already contain a Rust 1.58.0.
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      # Check that we don't have linting errors in release mode, too
+      - run: cargo clippy --all-targets --all-features
+        working-directory: yjit
+
+  make:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test_task: 'yjit-bindgen'
+            hint: 'To fix: use patch in logs'
+            # Build with YJIT+ZJIT for output that works in the most number of configurations
+            configure: '--with-gcc=clang-14 --enable-yjit=dev --enable-zjit'
+            libclang_path: '/usr/lib/llvm-14/lib/libclang.so.1'
+
+          - test_task: 'check'
+            # YJIT should be automatically built in release mode on x86-64 Linux with rustc present
+            #configure: "--enable-yjit RUSTC='rustc +1.58.0'"
+            configure: "RUSTC='rustc +1.58.0'"
+            rust_version: '1.58.0'
+
+          - test_task: 'check'
+            configure: '--enable-yjit=dev'
+
+          - test_task: 'check'
+            configure: '--enable-yjit=dev'
+            yjit_opts: '--yjit-call-threshold=1 --yjit-verify-ctx --yjit-code-gc'
+            specopts: '-T --yjit-call-threshold=1 -T --yjit-verify-ctx -T --yjit-code-gc'
+
+          - test_task: 'test-bundled-gems'
+            configure: '--enable-yjit=dev'
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUN_OPTS: ${{ matrix.yjit_opts }}
+      YJIT_BENCH_OPTS: ${{ matrix.yjit_bench_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
+      RUBY_DEBUG: ci
+      RUST_BACKTRACE: 1
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Install Rust
+        if: ${{ matrix.rust_version }}
+        run: rustup install ${{ matrix.rust_version }} --profile minimal
+
+      - name: Remove cargo
+        # Since this tests a `rustc` build for release, remove `cargo` to ensure
+        # that only `rustc` is used.
+        if: ${{ contains(matrix.configure, 'rustc') }}
+        run: sudo rm $(which -a cargo | uniq)
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix=$(pwd)/install ${{ matrix.configure }}
+
+      - run: make incs
+
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
+      - run: make
+
+      - name: Verify that --yjit-dump-disasm works
+        run: |
+          ./miniruby --yjit-call-threshold=1 --yjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      - name: Set ENV for YJIT
+        run: |
+          echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      # Check that the binary was built with YJIT
+      - name: Check YJIT enabled
+        run: ./miniruby --yjit -v | grep "+YJIT"
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ubuntu-22.04
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-yjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" MSPECOPT=--debug SPECOPTS="$SPECOPTS" \
+            YJIT_BENCH_OPTS="$YJIT_BENCH_OPTS" YJIT_BINDGEN_DIFF_OPTS="$YJIT_BINDGEN_DIFF_OPTS"
+        timeout-minutes: 90
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          SYNTAX_SUGGEST_TIMEOUT: '5'
+          YJIT_BINDGEN_DIFF_OPTS: '--exit-code'
+          LIBCLANG_PATH: ${{ matrix.libclang_path }}
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
+
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-latest
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/zjit-macos.yml b/.github/workflows/zjit-macos.yml
new file mode 100644
index 0000000000..707e50e36b
--- /dev/null
+++ b/.github/workflows/zjit-macos.yml
@@ -0,0 +1,239 @@
+name: ZJIT macOS
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test_task: 'check'
+            run_opts: '--zjit-call-threshold=1'
+            specopts: '-T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'check'
+            run_opts: '--zjit-disable-hir-opt --zjit-call-threshold=1'
+            specopts: '-T --zjit-disable-hir-opt -T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'zjit-check' # zjit-test + quick feedback of test_zjit.rb
+            configure: '--enable-yjit=dev --enable-zjit'
+            rust_version: "1.85.0"
+
+          - test_task: 'ruby'
+            hint: 'combo build test'
+            configure: '--enable-yjit --enable-zjit'
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUN_OPTS: ${{ matrix.run_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
+      TESTOPTS: ${{ matrix.testopts }}
+      RUST_BACKTRACE: 1
+      ZJIT_RB_BUG: 1
+
+    runs-on: macos-26
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - name: Install libraries
+        uses: ./.github/actions/setup/macos
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Install Rust
+        if: ${{ matrix.rust_version }}
+        run: |
+          rustup install ${{ matrix.rust_version }} --profile minimal
+          rustup default ${{ matrix.rust_version }}
+
+      - uses: taiki-e/install-action@4bc351f7f2614e48088386e2a0ad917ca3a7e4ba # v2.81.5
+        with:
+          tool: nextest@0.9
+        if: ${{ matrix.test_task == 'zjit-check' }}
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc ${{ matrix.configure }}
+
+      - run: make
+
+      - name: Verify that --zjit-dump-disasm works
+        run: |
+          ./miniruby --zjit-call-threshold=1 --zjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      - name: Set ENV for ZJIT
+        run: |
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: macos-26
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-zjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" \
+            SPECOPTS="$SPECOPTS" \
+            TESTOPTS="$TESTOPTS"
+        timeout-minutes: 60
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          EXCLUDES: '../src/test/.excludes-zjit'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          SYNTAX_SUGGEST_TIMEOUT: '30'
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
+
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-latest
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+  # Separated from `make` job to avoid making it a required status check for now
+  ruby-bench:
+    strategy:
+      matrix:
+        include:
+          # Test --call-threshold=2 with 2 iterations in total
+          - ruby_opts: '--zjit-call-threshold=2'
+            bench_opts: '--warmup=1 --bench=1 --excludes=shipit'
+            configure: '--enable-zjit=dev_nodebug' # --enable-zjit=dev is too slow
+
+    runs-on: macos-26
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/macos
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix="$(pwd)/install" ${{ matrix.configure }}
+
+      - run: make install
+
+      # setup/directories set MAKEFLAGS=-j4 for macOS, which randomly fails sqlite3.gem builds
+      - name: Unset MAKEFLAGS
+        run: echo "MAKEFLAGS=" >> "$GITHUB_ENV"
+
+      - name: Checkout ruby-bench
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+          repository: ruby/ruby-bench
+          path: ruby-bench
+
+      # If you want to skip failing benchmark, consider using `--excludes`.
+      # e.g. `bench_opts: '--warmup=1 --bench=1 --excludes=railsbench,lobsters'`
+      - name: Run ruby-bench
+        run: ruby run_benchmarks.rb -e "zjit::../build/install/bin/ruby ${{ matrix.ruby_opts }}" ${{ matrix.bench_opts }}
+        working-directory: ruby-bench
+        env:
+          BUNDLER_VERSION: 0
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/zjit-ubuntu.yml b/.github/workflows/zjit-ubuntu.yml
new file mode 100644
index 0000000000..1c3e3f6531
--- /dev/null
+++ b/.github/workflows/zjit-ubuntu.yml
@@ -0,0 +1,293 @@
+name: ZJIT Ubuntu
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  lint:
+    name: cargo clippy
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - run: cargo clippy --all-targets --all-features
+        working-directory: zjit
+
+  make:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test_task: 'check'
+            run_opts: '--zjit-call-threshold=1'
+            specopts: '-T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'check'
+            run_opts: '--zjit-disable-hir-opt --zjit-call-threshold=1'
+            specopts: '-T --zjit-disable-hir-opt -T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+            # The optimizer benefits from at least 1 iteration of profiling. Also, many
+            # regression tests in bootstraptest/test_yjit.rb assume call-threshold=2.
+          - test_task: 'btest'
+            run_opts: '--zjit-call-threshold=2'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'zjit-check' # zjit-test + quick feedback of test_zjit.rb
+            configure: '--enable-yjit --enable-zjit=dev'
+            rust_version: '1.85.0'
+
+          - test_task: 'zjit-bindgen'
+            hint: 'To fix: use patch in logs'
+            # Build with YJIT+ZJIT for output that works in the most number of configurations
+            configure: '--enable-zjit=dev --enable-yjit --with-gcc=clang-16'
+            clang_path: '/usr/bin/clang-16'
+            runs-on: 'ubuntu-24.04' # for clang-16
+
+          - test_task: 'test-bundled-gems'
+            configure: '--enable-zjit=dev'
+            run_opts: '--zjit-call-threshold=1'
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUN_OPTS: ${{ matrix.run_opts }}
+      YJIT_BENCH_OPTS: ${{ matrix.yjit_bench_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
+      TESTOPTS: ${{ matrix.testopts }}
+      RUBY_DEBUG: ci
+      BUNDLE_JOBS: 8 # for yjit-bench
+      RUST_BACKTRACE: 1
+      ZJIT_RB_BUG: 1
+
+    runs-on: ${{ matrix.runs-on || 'ubuntu-22.04' }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: taiki-e/install-action@4bc351f7f2614e48088386e2a0ad917ca3a7e4ba # v2.81.5
+        with:
+          tool: nextest@0.9
+        if: ${{ matrix.test_task == 'zjit-check' }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Install Rust
+        if: ${{ matrix.rust_version }}
+        run: |
+          rustup install ${{ matrix.rust_version }} --profile minimal
+          rustup default ${{ matrix.rust_version }}
+
+      - name: Install rustfmt
+        if: ${{ matrix.test_task == 'zjit-bindgen' }}
+        run: rustup component add rustfmt
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix=$(pwd)/install ${{ matrix.configure }}
+
+      - run: make incs
+
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
+      - run: make
+
+      - name: Verify that --zjit-dump-disasm works
+        run: |
+          ./miniruby --zjit-call-threshold=1 --zjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      # Check that the binary was built with ZJIT
+      - name: Check ZJIT enabled
+        run: ./miniruby --zjit -v | grep "+ZJIT"
+        if: ${{ matrix.configure != '--disable-zjit' }}
+
+      - name: Set ENV for ZJIT
+        run: |
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.runs-on || 'ubuntu-22.04' }}
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-zjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" MSPECOPT=--debug SPECOPTS="$SPECOPTS" \
+            TESTOPTS="$TESTOPTS" \
+            ZJIT_BINDGEN_DIFF_OPTS="$ZJIT_BINDGEN_DIFF_OPTS"
+        timeout-minutes: 90
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          EXCLUDES: '../src/test/.excludes-zjit'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          SYNTAX_SUGGEST_TIMEOUT: '30'
+          ZJIT_BINDGEN_DIFF_OPTS: '--exit-code'
+          CLANG_PATH: ${{ matrix.clang_path }}
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
+
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-22.04
+    needs: [make]
+    steps:
+      - name: ${{ github.workflow }} jobs have failed
+        run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+  # Separated from `make` job to avoid making it a required status check for now
+  ruby-bench:
+    strategy:
+      matrix:
+        include:
+          # Test --call-threshold=2 with 2 iterations in total
+          - ruby_opts: '--zjit-call-threshold=2'
+            bench_opts: '--warmup=1 --bench=1 --excludes=shipit'
+            configure: '--enable-zjit=dev_nodebug' # --enable-zjit=dev is too slow
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix="$(pwd)/install" ${{ matrix.configure }}
+
+      - run: make install
+
+      - name: Checkout ruby-bench
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          repository: ruby/ruby-bench
+          persist-credentials: false
+          path: ruby-bench
+
+      # If you want to skip failing benchmark, consider using `--excludes`.
+      # e.g. `bench_opts: '--warmup=1 --bench=1 --excludes=railsbench,lobsters'`
+      - name: Run ruby-bench
+        run: ruby run_benchmarks.rb -e "zjit::../build/install/bin/ruby ${{ matrix.ruby_opts }}" ${{ matrix.bench_opts }}
+        working-directory: ruby-bench
+        env:
+          BUNDLER_VERSION: 0
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/zizmor.yml b/.github/zizmor.yml
new file mode 100644
index 0000000000..2a8cad1d5c
--- /dev/null
+++ b/.github/zizmor.yml
@@ -0,0 +1,33 @@
+# Ignore existing findings (baseline)
+# Composite action findings are suppressed inline with # zizmor: ignore
+rules:
+  artipacked:
+    # These jobs push back to the repo and need persisted credentials.
+    ignore:
+      - bundled_gems.yml
+      - default_gems_list.yml
+      - post_push.yml
+      - sync_default_gems.yml
+  dangerous-triggers:
+    ignore:
+      - auto_request_review.yml
+      - auto_review_pr.yml
+      - labeler.yml
+      - pr-playground.yml
+  dependabot-cooldown:
+    ignore:
+      - dependabot.yml
+  misfeature:
+    ignore:
+      - mingw.yml
+      - tarball-windows.yml
+      - windows.yml
+  unpinned-images:
+    ignore:
+      - compilers.yml
+  secrets-outside-env:
+    # All committers with write access are trusted; no need for environment-scoped secrets.
+    disable: true
+  unpinned-uses:
+    ignore:
+      - wsl.yml
diff --git a/.gitignore b/.gitignore
index fe7c04823b..7ead3a81f5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,23 +10,27 @@
 *.dylib
 *.elc
 *.i
+*.ii
 *.inc
 *.log
 *.o
+*.o.tmp
 *.obj
 *.old
 *.orig
 *.pch
 *.pdb
+*.rbinc
+*.rbbin
 *.rej
 *.s
 *.sav
 *.sl
 *.so
+*.so.*
 *.swp
 *.yarb
 *~
-.*-*
 .*.list
 .*.time
 .DS_Store
@@ -37,6 +41,7 @@
 .ppack
 .svn
 .time
+.ruby-version
 Makefile
 cygruby*.def
 extconf.h
@@ -46,6 +51,7 @@ y.tab.c
 *.gcno
 *.gcov
 *.vscode
+!misc/.vscode
 lcov*.info
 
 # /
@@ -56,6 +62,8 @@ lcov*.info
 /*.pc
 /*.rc
 /*_prelude.c
+/.downloaded-cache
+/.top-enc.mk
 /build*/
 /COPYING.LIB
 /ChangeLog
@@ -89,6 +97,7 @@ lcov*.info
 /enc.mk
 /encdb.h
 /exts.mk
+/gc/*/exts.mk
 /goruby
 /id.[ch]
 /largefile.h
@@ -116,28 +125,34 @@ lcov*.info
 /rename2.h
 /repack
 /revision.h
+/revision.tmp
+/ripper.tmp.y
 /riscos
 /rubicon
 /ruby
 /ruby-runner
 /ruby-runner.h
 /ruby-man.rd.gz
+/rubyspec_temp
 /run.gdb
 /sizes.c
+/static-ruby
 /test.rb
 /test-coverage.dat
 /tmp
+/vcpkg_installed
 /transdb.h
 /uncommon.mk
 /verconf.h
 /verconf.mk
 /web
-/yasmdata.rb
 
 # /bin/
 
 /bin/*.exe
 /bin/*.dll
+/bin/goruby
+/bin/ruby
 
 # /benchmark/
 /benchmark/bm_require.data
@@ -153,6 +168,7 @@ lcov*.info
 
 # /coroutine/
 !/coroutine/**/*.s
+!/coroutine/**/*.S
 
 # /enc/trans/
 /enc/trans/*.c
@@ -169,11 +185,17 @@ lcov*.info
 /ext/configure-ext.mk
 /ext/*/exts.mk
 
+# /ext/-test-/cxxanyargs
+/ext/-test-/cxxanyargs/failure*.failed
+
 # /ext/-test-/win32/dln/
 /ext/-test-/win32/dln/dlntest.dll
 /ext/-test-/win32/dln/dlntest.exp
 /ext/-test-/win32/dln/dlntest.lib
 
+# /ext/-test-/gems
+/ext/-test-/gems
+
 # /ext/etc/
 /ext/etc/constdefs.h
 
@@ -186,7 +208,10 @@ lcov*.info
 
 # /ext/ripper/
 /ext/ripper/eventids1.c
+/ext/ripper/eventids1.h
+/ext/ripper/.eventids2-check
 /ext/ripper/eventids2table.c
+/ext/ripper/ripper_init.c
 /ext/ripper/ripper.*
 /ext/ripper/ids1
 /ext/ripper/ids2
@@ -205,7 +230,10 @@ lcov*.info
 /lib/ruby/[1-9]*.*
 /lib/ruby/vendor_ruby
 
-# /spec/bundler
+# /misc/
+/misc/**/__pycache__
+
+# for `make test-bundler`
 /.rspec_status
 
 # /tool/
@@ -215,7 +243,49 @@ lcov*.info
 # /win32/
 /win32/*.ico
 
-# MJIT
-/rb_mjit_header.h
-/mjit_config.h
-/include/ruby-*/*/rb_mjit_min_header-*.h
+
+# YJIT
+/yjit-bench
+/yjit_exit_locations.dump
+
+# Rust
+/target
+
+# /wasm/
+/wasm/tests/*.wasm
+
+# prism
+/lib/prism/compiler.rb
+/lib/prism/dispatcher.rb
+/lib/prism/dot_visitor.rb
+/lib/prism/dsl.rb
+/lib/prism/inspect_visitor.rb
+/lib/prism/mutation_compiler.rb
+/lib/prism/node.rb
+/lib/prism/reflection.rb
+/lib/prism/serialize.rb
+/lib/prism/visitor.rb
+/prism/internal/diagnostic.h
+/prism/api_node.c
+/prism/ast.h
+/prism/diagnostic.c
+/prism/json.c
+/prism/node.c
+/prism/prettyprint.c
+/prism/serialize.c
+/prism/tokens.c
+/prism/srcs.mk
+/dump_ast
+
+# prism (old file)
+/prism/token_type.c
+
+# tool/update-NEWS-gemlist.rb
+/bundled_gems.json
+/default_gems.json
+/gems/default_gems
+
+# AI agents
+/.claude
+/AGENTS.md
+/CLAUDE.md
diff --git a/.indent.pro b/.indent.pro
index 6a207a0554..1d61cbcad1 100644
--- a/.indent.pro
+++ b/.indent.pro
@@ -2,12 +2,15 @@
 -nbbb
 -nbc
 -br
+-brs
 -nbs
 -ncdb
--ce
--cli0.5
+-nce
+-cdw
+-cli2
+-cbi2
 -ndj
--ei
+-ncs
 -nfc1
 -i4
 -l120
@@ -16,6 +19,14 @@
 -psl
 -sc
 -sob
+-sbi4
+-nut
+-par
 
 -TID
 -TVALUE
+-Tst_data_t
+-Tst_index_t
+-Tst_table
+-Trb_data_type_t
+-TFILE
diff --git a/.mailmap b/.mailmap
new file mode 100644
index 0000000000..213a0f4916
--- /dev/null
+++ b/.mailmap
@@ -0,0 +1,431 @@
+git[bot]                                <svn-admin@ruby-lang.org>
+git[bot]                                <svn-admin@ruby-lang.org> git <svn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+svn[bot]                                <svn-admin@ruby-lang.org> svn <svn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# a_matsuda
+Akira Matsuda                           <ronnie@dio.jp>
+Akira Matsuda                           <ronnie@dio.jp> <a_matsuda@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# aamine
+Minero Aoki                             <aamine@loveruby.net>
+Minero Aoki                             <aamine@loveruby.net> <aamine@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# akira
+akira yamada                            <akira@ruby-lang.org>
+## akira yamada                         <akira@ruby-lang.org> <akira@rice.p.arika.org>
+akira yamada                            <akira@ruby-lang.org> <akira@arika.org>
+akira yamada                            <akira@ruby-lang.org> <akira@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# akiyoshi
+AKIYOSHI, Masamichi                     <masamichi.akiyoshi@hp.com>
+AKIYOSHI, Masamichi                     <masamichi.akiyoshi@hp.com> <akiyoshi@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# akr
+Tanaka Akira                            <akr@fsij.org>
+Tanaka Akira                            <akr@fsij.org> <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# arai
+Koji Arai                               <jca02266@nifty.ne.jp>
+Koji Arai                               <jca02266@nifty.ne.jp> <arai@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# arton
+Akio Tajima                             <artonx@yahoo.co.jp>
+Akio Tajima                             <artonx@yahoo.co.jp> <arton@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# aycabta
+aycabta                                 <aycabta@gmail.com>
+aycabta                                 <aycabta@gmail.com> <aycabta@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ayumin
+Ayumu AIZAWA                            <ayumu.aizawa@gmail.com>
+Ayumu AIZAWA                            <ayumu.aizawa@gmail.com> <ayumin@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# azav
+Alexander Zavorine                      <alexandre.zavorine@nokia.com>
+Alexander Zavorine                      <alexandre.zavorine@nokia.com> <azav@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# charliesome
+Charlie Somerville                      <charliesome@ruby-lang.org>
+Charlie Somerville                      <charliesome@ruby-lang.org> <charliesome@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# dave
+Dave Thomas                             <dave@pragprog.com>
+Dave Thomas                             <dave@pragprog.com> <dave@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# davidflanagan
+David Flanagan                          <davidflanagan@ruby-lang.org>
+David Flanagan                          <davidflanagan@ruby-lang.org> <david@think32>
+David Flanagan                          <davidflanagan@ruby-lang.org> <david@davidflanagan.com>
+David Flanagan                          <davidflanagan@ruby-lang.org> <davidflanagan@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# dblack
+David A. Black                          <dblack@rubypal.com>
+David A. Black                          <dblack@rubypal.com> <dblack@wobblini.net>
+David A. Black                          <dblack@rubypal.com> <dblack@superlink.net>
+David A. Black                          <dblack@rubypal.com> <dblack@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# drbrain
+Eric Hodel                              <drbrain@segment7.net>
+Eric Hodel                              <drbrain@segment7.net> <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# duerst
+Martin Dürst                            <duerst@it.aoyama.ac.jp>
+Martin Dürst                            <duerst@it.aoyama.ac.jp> <duerst@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# eban
+WATANABE Hirofumi                       <eban@ruby-lang.org>
+WATANABE Hirofumi                       <eban@ruby-lang.org> <eban@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# emboss
+Martin Bosslet                          <Martin.Bosslet@gmail.com>
+Martin Bosslet                          <Martin.Bosslet@gmail.com> <Martin.Bosslet@googlemail.com>
+Martin Bosslet                          <Martin.Bosslet@gmail.com> <emboss@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# eregon
+Benoit Daloze                           <eregontp@gmail.com>
+Benoit Daloze                           <eregontp@gmail.com> <eregon@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# evan
+Evan Phoenix                            <evan@ruby-lang.org>
+Evan Phoenix                            <evan@ruby-lang.org> <evan@fallingsnow.net>
+Evan Phoenix                            <evan@ruby-lang.org> <evan@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# glass
+Masaki Matsushita                       <glass.saga@gmail.com>
+Masaki Matsushita                       <glass.saga@gmail.com> <glass@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gogotanaka
+Kazuki Tanaka                           <gogotanaka@ruby-lang.org>
+Kazuki Tanaka                           <gogotanaka@ruby-lang.org> <gogotanaka@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gotoken
+Kentaro Goto                            <gotoken@gmail.com>
+Kentaro Goto                            <gotoken@gmail.com> <gotoken@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gotoyuzo
+GOTOU Yuuzou                            <gotoyuzo@notwork.org>
+GOTOU Yuuzou                            <gotoyuzo@notwork.org> <gotoyuzo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gsinclair
+Gavin Sinclair                          <gsinclair@soyabean.com.au>
+Gavin Sinclair                          <gsinclair@soyabean.com.au> <gsinclair@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# H_Konishi
+KONISHI Hiromasa                        <konishih@fd6.so-net.ne.jp>
+KONISHI Hiromasa                        <konishih@fd6.so-net.ne.jp> <H_Konishi@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# headius
+Charles Oliver Nutter                   <headius@headius.com>
+Charles Oliver Nutter                   <headius@headius.com> <headius@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# hone
+Terence Lee                             <hone@heroku.com>
+Terence Lee                             <hone@heroku.com> <hone@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# hsbt
+Hiroshi SHIBATA                         <hsbt@ruby-lang.org>
+Hiroshi SHIBATA                         <hsbt@ruby-lang.org> <hsbt@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# iwamatsu
+Nobuhiro Iwamatsu                       <iwamatsu@nigauri.org>
+Nobuhiro Iwamatsu                       <iwamatsu@nigauri.org> <iwamatsu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# jeg2
+James Edward Gray II                    <james@graysoftinc.com>
+James Edward Gray II                    <james@graysoftinc.com> <jeg2@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# jim
+Jim Weirich                             <jim@tardis.local>
+Jim Weirich                             <jim@tardis.local> <jim@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# k0kubun
+Takashi Kokubun                         <takashikkbn@gmail.com>
+Takashi Kokubun                         <takashikkbn@gmail.com> <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kanemoto
+Yutaka Kanemoto                         <kanemoto@ruby-lang.org>
+Yutaka Kanemoto                         <kanemoto@ruby-lang.org> <kanemoto@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# katsu
+UENO Katsuhiro                          <katsu@blue.sky.or.jp>
+UENO Katsuhiro                          <katsu@blue.sky.or.jp> <katsu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kazu
+Kazuhiro NISHIYAMA                      <zn@mbf.nifty.com>
+Kazuhiro NISHIYAMA                      <zn@mbf.nifty.com> <kazu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# keiju
+Keiju Ishitsuka                         <keiju@ishitsuka.com>
+Keiju Ishitsuka                         <keiju@ishitsuka.com> <keiju@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# knu
+Akinori MUSHA                           <knu@iDaemons.org>
+Akinori MUSHA                           <knu@iDaemons.org> <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ko1
+Koichi Sasada                           <ko1@atdot.net>
+Koichi Sasada                           <ko1@atdot.net> <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kosaki
+KOSAKI Motohiro                         <kosaki.motohiro@gmail.com>
+KOSAKI Motohiro                         <kosaki.motohiro@gmail.com> <kosaki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kosako
+K.Kosako                                <sndgk393@ybb.ne.jp>
+K.Kosako                                <sndgk393@ybb.ne.jp> <kosako@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kou
+Sutou Kouhei                            <kou@clear-code.com>
+Sutou Kouhei                            <kou@clear-code.com> <kou@cozmixng.org>
+Sutou Kouhei                            <kou@clear-code.com> <kou@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kouji
+Kouji Takao                             <kouji.takao@gmail.com>
+Kouji Takao                             <kouji.takao@gmail.com> <kouji@takao7.net>
+Kouji Takao                             <kouji.takao@gmail.com> <kouji@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ksaito
+Kazuo Saito                             <ksaito@uranus.dti.ne.jp>
+Kazuo Saito                             <ksaito@uranus.dti.ne.jp> <ksaito@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ktsj
+Kazuki Tsujimoto                        <kazuki@callcc.net>
+Kazuki Tsujimoto                        <kazuki@callcc.net> <ktsj@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# luislavena
+Luis Lavena                             <luislavena@gmail.com>
+Luis Lavena                             <luislavena@gmail.com> <luislavena@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# mame
+Yusuke Endoh                            <mame@ruby-lang.org>
+## Yusuke Endoh                         <mame@ruby-lang.org> <mame@tsg.ne.jp>
+Yusuke Endoh                            <mame@ruby-lang.org> <mame@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# marcandre
+Marc-Andre Lafortune                    <github@marc-andre.ca>
+Marc-Andre Lafortune                    <ruby-core@marc-andre.ca>
+Marc-Andre Lafortune                    <ruby-core@marc-andre.ca> <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# matz
+Yukihiro "Matz" Matsumoto               <matz@ruby.or.jp>
+Yukihiro "Matz" Matsumoto               <matz@ruby.or.jp> <matz@ruby-lang.org>
+Yukihiro "Matz" Matsumoto               <matz@ruby.or.jp> <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# michal
+Michal Rokos                            <michal@ruby-lang.org>
+Michal Rokos                            <michal@ruby-lang.org> <michal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# mneumann
+Michael Neumann                         <mneumann@ruby-lang.org>
+Michael Neumann                         <mneumann@ruby-lang.org> <mneumann@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# mrkn
+Kenta Murata                            <mrkn@mrkn.jp>
+Kenta Murata                            <mrkn@mrkn.jp> <muraken@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+Kenta Murata                            <mrkn@mrkn.jp> <3959+mrkn@users.noreply.github.com>
+Kenta Murata                            <mrkn@mrkn.jp> <mrkn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nagachika
+nagachika                               <nagachika@ruby-lang.org>
+nagachika                               <nagachika@ruby-lang.org> <nagachika@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nagai
+Hidetoshi NAGAI                         <nagai@ai.kyutech.ac.jp>
+Hidetoshi NAGAI                         <nagai@ai.kyutech.ac.jp> <nagai@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nahi
+Hiroshi Nakamura                        <nahi@ruby-lang.org>
+Hiroshi Nakamura                        <nahi@ruby-lang.org> <nahi@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nari
+Narihiro Nakamura                       <authornari@gmail.com>
+Narihiro Nakamura                       <authornari@gmail.com> <nari@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# naruse
+NARUSE, Yui                             <naruse@airemix.jp>
+NARUSE, Yui                             <naruse@airemix.jp> <naruse@ruby-lang.org>
+NARUSE, Yui                             <naruse@airemix.jp> <naruse@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ngoto
+Naohisa Goto                            <ngotogenome@gmail.com>
+Naohisa Goto                            <ngotogenome@gmail.com> <ngoto@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nobu
+Nobuyoshi Nakada                        <nobu@ruby-lang.org>
+Nobuyoshi Nakada                        <nobu@ruby-lang.org> <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# normal
+Eric Wong                               <normal@ruby-lang.org>
+Eric Wong                               <normal@ruby-lang.org> <e@80x24.org>
+Eric Wong                               <normal@ruby-lang.org> <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ntalbott
+Nathaniel Talbott                       <ntalbott@ruby-lang.org>
+Nathaniel Talbott                       <ntalbott@ruby-lang.org> <ntalbott@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ocean
+Hirokazu Yamamoto                       <ocean@m2.ccsnet.ne.jp>
+Hirokazu Yamamoto                       <ocean@m2.ccsnet.ne.jp> <ocean@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# odaira
+Rei Odaira                              <rodaira@us.ibm.com>
+Rei Odaira                              <rodaira@us.ibm.com> <Rei.Odaira@gmail.com>
+Rei Odaira                              <rodaira@us.ibm.com> <odaira@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# okkez
+okkez                                   <okkez000@gmail.com>
+okkez                                   <okkez000@gmail.com> <okkez@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# rhe
+Kazuki Yamaguchi                        <k@rhe.jp>
+Kazuki Yamaguchi                        <k@rhe.jp> <rhe@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ryan
+Ryan Davis                              <ryand-github@zenspider.com>
+Ryan Davis                              <ryand-github@zenspider.com> <ryand-ruby@zenspider.com>
+Ryan Davis                              <ryand-github@zenspider.com> <ryan@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# samuel
+Samuel Williams                         <samuel.williams@oriontransfer.co.nz>
+Samuel Williams                         <samuel.williams@oriontransfer.co.nz> <samuel@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# seki
+Masatoshi SEKI                          <m_seki@mva.biglobe.ne.jp>
+Masatoshi SEKI                          <m_seki@mva.biglobe.ne.jp> <seki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ser
+Sean Russell                            <ser@germane-software.com>
+Sean Russell                            <ser@germane-software.com> <ser@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shigek
+Shigeo Kobayashi                        <shigek@ruby-lang.org>
+Shigeo Kobayashi                        <shigek@ruby-lang.org> <shigek@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shirosaki
+Hiroshi Shirosaki                       <h.shirosaki@gmail.com>
+Hiroshi Shirosaki                       <h.shirosaki@gmail.com> <shirosaki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# sho-h
+Sho Hashimoto                           <sho-h@ruby-lang.org>
+Sho Hashimoto                           <sho-h@ruby-lang.org> <sho-h@netlab.jp>
+Sho Hashimoto                           <sho-h@ruby-lang.org> <sho.hsmt@gmail.com>
+Sho Hashimoto                           <sho-h@ruby-lang.org> <sho-h@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shugo
+Shugo Maeda                             <shugo@ruby-lang.org>
+Shugo Maeda                             <shugo@ruby-lang.org> <shugo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shyouhei
+卜部昌平                                    <shyouhei@ruby-lang.org>
+卜部昌平                                    <shyouhei@ruby-lang.org> <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# siena
+Siena.                                  <siena@faculty.chiba-u.jp>
+Siena.                                  <siena@faculty.chiba-u.jp> <siena@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# sonots
+sonots                                  <sonots@gmail.com>
+sonots                                  <sonots@gmail.com> <sonots@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# sorah
+Sorah Fukumori                          <her@sorah.jp>
+Sorah Fukumori                          <her@sorah.jp> <sorah@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# stomar
+Marcus Stollsteimer                     <sto.mar@web.de>
+Marcus Stollsteimer                     <sto.mar@web.de> <stomar@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# suke
+Masaki Suketa                           <masaki.suketa@nifty.ne.jp>
+Masaki Suketa                           <masaki.suketa@nifty.ne.jp> <suke@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tadd
+Tadashi Saito                           <tad.a.digger@gmail.com>
+Tadashi Saito                           <tad.a.digger@gmail.com> <tadd@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tadf
+Tadayoshi Funaba                        <tadf@dotrb.org>
+Tadayoshi Funaba                        <tadf@dotrb.org> <tadf@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# takano32
+TAKANO Mitsuhiro                        <takano32@gmail.com>
+TAKANO Mitsuhiro                        <takano32@gmail.com> <takano32@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tarui
+Masaya Tarui                            <tarui@ruby-lang.org>
+Masaya Tarui                            <tarui@ruby-lang.org> <tarui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# technorama
+Technorama Ltd.                         <oss-ruby@technorama.net>
+Technorama Ltd.                         <oss-ruby@technorama.net> <technorama@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tenderlove
+Aaron Patterson                         <tenderlove@ruby-lang.org>
+Aaron Patterson                         <tenderlove@ruby-lang.org> <tenderlove@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tmm1
+Aman Gupta                              <ruby@tmm1.net>
+Aman Gupta                              <ruby@tmm1.net> <tmm1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ts
+Guy Decoux                              <ts@moulon.inra.fr>
+Guy Decoux                              <ts@moulon.inra.fr> <ts@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ttate
+Takaaki Tateishi                        <ttate@ttsky.net>
+## Takaaki Tateishi                     <ttate@ttsky.net> <ttate@kt.jaist.ac.jp>
+Takaaki Tateishi                        <ttate@ttsky.net> <ttate@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# uema2
+Takaaki Uematsu                         <uema2x@jcom.home.ne.jp>
+Takaaki Uematsu                         <uema2x@jcom.home.ne.jp> <uema2@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# usa
+U.Nakamura                              <usa@ruby-lang.org>
+U.Nakamura                              <usa@ruby-lang.org> <usa@garbagecollect.jp>
+U.Nakamura                              <usa@ruby-lang.org> <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# wakou
+Wakou Aoyama                            <wakou@ruby-lang.org>
+Wakou Aoyama                            <wakou@ruby-lang.org> <wakou@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# wanabe
+wanabe                                  <s.wanabe@gmail.com>
+wanabe                                  <s.wanabe@gmail.com> <wanabe@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# watson1978
+Watson                                  <watson1978@gmail.com>
+Watson                                  <watson1978@gmail.com> <watson1978@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# wew
+William Webber                          <william@williamwebber.com>
+William Webber                          <william@williamwebber.com> <wew@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# why
+why the lucky stiff                     <why@ruby-lang.org>
+why the lucky stiff                     <why@ruby-lang.org> <why@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# xibbar
+Takeyuki FUJIOKA                        <xibbar@ruby-lang.org>
+Takeyuki FUJIOKA                        <xibbar@ruby-lang.org> <xibbar@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# yugui
+Yuki Yugui Sonoda                       <yugui@yugui.jp>
+Yuki Yugui Sonoda                       <yugui@yugui.jp> <yugui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# yui-knk
+yui-knk                                 <spiketeika@gmail.com>
+yui-knk                                 <spiketeika@gmail.com> <yui-knk@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# yuki
+Yuki Nishijima                          <yuki24@hey.com>
+Yuki Nishijima                          <yuki24@hey.com> <mail@yukinishijima.net>
+Yuki Nishijima                          <yuki24@hey.com> <yuki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# zsombor
+Dee Zsombor                             <zsombor@ruby-lang.org>
+Dee Zsombor                             <zsombor@ruby-lang.org> <zsombor@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# zzak
+zzak                                    <zzakscott@gmail.com>
+zzak                                    <zzakscott@gmail.com> <zzak@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
diff --git a/.rdoc_options b/.rdoc_options
new file mode 100644
index 0000000000..5172911e16
--- /dev/null
+++ b/.rdoc_options
@@ -0,0 +1,37 @@
+---
+page_dir: doc
+main_page: index.md
+title: Documentation for Ruby development version
+visibility: :private
+rdoc_include:
+- doc
+
+exclude:
+- \.gemspec\z
+- lib/set/subclass_compatible.rb
+
+autolink_excluded_words:
+- Box
+- Class
+- Method
+- Module
+- Process
+- RDoc
+- Ruby
+- Set
+- ZJIT
+- YJIT
+
+canonical_root: https://docs.ruby-lang.org/en/master
+
+footer_content:
+  Ruby:
+    Documentation: index.html
+    Official Website: https://www.ruby-lang.org/
+    Playground: https://ruby.github.io/play-ruby/
+  Resources:
+    GitHub: https://github.com/ruby/ruby
+    Issue Tracker: https://bugs.ruby-lang.org/projects/ruby-master/issues
+    RubyGems: https://rubygems.org/
+  Community:
+    X: https://x.com/rubylangorg
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index a4e6626362..0000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,493 +0,0 @@
-# -*- YAML -*-
-# Copyright (C) 2011 Urabe, Shyouhei.  All rights reserved.
-#
-# This file is  a part of the programming language  Ruby.  Permission is hereby
-# granted,  to either  redistribute  or  modify this  file,  provided that  the
-# conditions  mentioned in  the file  COPYING are  met.  Consult  the  file for
-# details.
-
-# This is  a Travis-CI  build configuration file.   The list  of configurations
-# available is located in
-#
-#     http://about.travis-ci.org/docs/user/build-configuration/
-#
-# and as Ruby itself is a project written in C language,
-#
-#     http://about.travis-ci.org/docs/user/languages/c/
-#
-# is also a good place to look at.
-
-language: c
-
-os: linux
-
-dist: xenial
-
-git:
-  quiet: true
-
-cache:
-  ccache: true
-  directories:
-    - $HOME/config_2nd
-    - $HOME/.downloaded-cache
-
-env:
-  global:
-    # Reset timestamps early
-    - _=$(touch NEWS && find . -type f -exec touch -r NEWS {} +)
-    - CONFIGURE_TTY=no
-    - CCACHE_COMPILERCHECK=none
-    - CCACHE_NOCOMPRESS=1
-    - CCACHE_MAXSIZE=512Mi
-    - NPROC="`nproc`"
-    # JOBS and SETARCH are overridden when necessary; see below.
-    - JOBS=-j$((1+${NPROC}))
-    - SETARCH=
-    - RUBY_PREFIX=/tmp/ruby-prefix
-    - GEMS_FOR_TEST='timezone tzinfo'
-    - UPDATE_UNICODE="UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
-    # https://github.com/travis-ci/travis-build/blob/e411371dda21430a60f61b8f3f57943d2fe4d344/lib/travis/build/bash/travis_apt_get_options.bash#L7
-    - travis_apt_get_options='--allow-downgrades --allow-remove-essential --allow-change-held-packages'
-    - travis_apt_get_options="-yq --no-install-suggests --no-install-recommends $travis_apt_get_options"
-
-.org.ruby-lang.ci.matrix-definitions:
-
-  - &cron-only
-    if: (type = cron) AND (branch = master) AND (fork = false)
-
-  - &make-test-only
-    script:
-      - $SETARCH make -s test TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
-
-  - &gcc-8
-    compiler: gcc-8
-    # # Not using addon to control retries
-    # addons:
-    #   apt:
-    #     sources:
-    #       - ubuntu-toolchain-r-test
-    before_install:
-      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - |-
-        ${BEFORE_INSTALL}
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
-          gcc-8 \
-          g++-8 \
-          libffi-dev \
-          libgdbm-dev \
-          libgmp-dev \
-          libjemalloc-dev \
-          libncurses5-dev \
-          libncursesw5-dev \
-          libreadline6-dev \
-          libssl-dev \
-          libyaml-dev \
-          openssl \
-          valgrind \
-          zlib1g-dev
-
-  - &clang-8
-    compiler: clang-8
-    addons:
-      apt:
-        # Not doing this manually unlike other sources, because it has been stable.
-        sources:
-          - llvm-toolchain-xenial-8
-        config:
-          retries: true
-    before_install:
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - |-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
-          clang-8 \
-          llvm-8-tools \
-          libffi-dev \
-          libgdbm-dev \
-          libgmp-dev \
-          libjemalloc-dev \
-          libncurses5-dev \
-          libncursesw5-dev \
-          libreadline6-dev \
-          libssl-dev \
-          libyaml-dev \
-          openssl \
-          valgrind \
-          zlib1g-dev
-
-  # --------
-
-  - &x86_64-linux
-    name: x86_64-linux
-    <<: *gcc-8
-    env:
-      - TEST_MJIT_SYMBOLS=1 # detect exports missing for MJIT
-
-  - &jemalloc
-    name: --with-jemalloc
-    <<: *gcc-8
-    <<: *cron-only
-    env:
-      - CONFIG_FLAG='--with-gmp --with-jemalloc --with-valgrind'
-
-  - &assertions
-    name: RUBY_DEBUG=1
-    <<: *gcc-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags='-DRUBY_DEBUG -DVM_CHECK_MODE=1 -DTRANSIENT_HEAP_CHECK_MODE -DRGENGC_CHECK_MODE -DENC_DEBUG'
-
-  - &VM_CHECK_MODE
-    name: VM_CHECK_MODE=3
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DVM_CHECK_MODE=0x0003
-
-  - &SUPPORT_JOKE
-    name: SUPPORT_JOKE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - BEFORE_INSTALL="sed vm_opts.h -e 's/OPT_SUPPORT_JOKE *0/OPT_SUPPORT_JOKE 1/' -i"
-
-  - &WITH_COROUTINE_UCONTEXT
-    name: COROUTINE=ucontext
-    <<: *gcc-8
-    <<: *cron-only
-    env:
-      - CONFIG_FLAG='--with-coroutine=ucontext'
-
-  - &WITH_COROUTINE_COPY
-    name: COROUTINE=copy
-    <<: *gcc-8
-    <<: *cron-only
-    env:
-      - CONFIG_FLAG='--with-coroutine=copy'
-
-  - &TOKEN_THREADED_CODE
-    name: TOKEN_THREADED_CODE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DOPT_THREADED_CODE=1
-
-  - &CALL_THREADED_CODE
-    name: CALL_THREADED_CODE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DOPT_THREADED_CODE=2
-
-  - &NO_THREADED_CODE
-    name: NO_THREADED_CODE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DOPT_THREADED_CODE=3
-
-  - &ASAN
-    name: -fsanitize=address
-    <<: *clang-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - ASAN_OPTIONS=detect_leaks=0
-      - cflags='-U_FORTIFY_SOURCE -march=native -fsanitize=address -fno-omit-frame-pointer -fPIC'
-      - debugflags=-ggdb3
-      - optflags=-O1
-      - LD=clang-8
-      - LDFLAGS='-fsanitize=address -fPIC'
-      - CONFIG_FLAG='--with-out-ext=openssl --without-gmp --without-jemalloc --without-valgrind'
-
-  - &MSAN
-    name: -fsanitize=memory
-    <<: *clang-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cflags='-U_FORTIFY_SOURCE -fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer -fPIC'
-      - optflags=-O1
-      - LD=clang-8
-      - LDFLAGS='-fsanitize=memory -fPIC'
-      - CONFIG_FLAG='--with-out-ext=openssl --without-gmp --without-jemalloc --without-valgrind'
-
-  - &UBSAN
-    name: -fsanitize=undefined
-    <<: *clang-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cflags='-U_FORTIFY_SOURCE -fsanitize=undefined,integer,nullability -fno-sanitize=implicit-integer-sign-change,unsigned-integer-overflow'
-      - cppflags=-DUNALIGNED_WORD_ACCESS=0
-      - debugflags=-ggdb3
-      - optflags='-O1 -march=native'
-      - LD=clang-8
-      - LDFLAGS='-fsanitize=undefined,integer,nullability -fno-sanitize=implicit-integer-sign-change,unsigned-integer-overflow'
-
-  - &i686-linux
-    name: i686-linux
-    compiler: gcc-8
-    env:
-      - GCC_FLAGS=-m32
-      - CXX='g++-8 -m32'
-      - debugflags=-g0
-      - SETARCH='setarch i686 --verbose --3gb'
-    # # Not using addon to control retries
-    # addons:
-    #   apt:
-    #     sources:
-    #       - ubuntu-toolchain-r-test
-    before_install:
-      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - |-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
-          gcc-8-multilib \
-          g++-8 \
-          g++-8-multilib \
-          libstdc++-8-dev:i386 \
-          libffi-dev:i386 \
-          libffi6:i386 \
-          libgdbm-dev:i386 \
-          libgdbm3:i386 \
-          libncurses5-dev:i386 \
-          libncurses5:i386 \
-          libncursesw5-dev:i386 \
-          libreadline6-dev:i386 \
-          libreadline6:i386 \
-          libssl-dev:i386 \
-          libssl1.0.0:i386 \
-          linux-libc-dev:i386 \
-          zlib1g-dev:i386 \
-          zlib1g:i386
-
-  - &pedanticism
-    name: -std=c99 -pedantic
-    compiler: clang
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - GCC_FLAGS='-std=c99 -Werror=pedantic -pedantic-errors'
-      - CONFIG_FLAG=
-      - JOBS=
-      - >-
-        warnflags='
-        -Wall
-        -Wextra
-        -Werror=deprecated-declarations
-        -Werror=division-by-zero
-        -Werror=extra-tokens
-        -Werror=implicit-function-declaration
-        -Werror=implicit-int
-        -Werror=pointer-arith
-        -Werror=shorten-64-to-32
-        -Werror=write-strings
-        -Wmissing-noreturn
-        -Wno-constant-logical-operand
-        -Wno-missing-field-initializers
-        -Wno-overlength-strings
-        -Wno-parentheses-equality
-        -Wno-self-assign
-        -Wno-tautological-compare
-        -Wno-unused-local-typedef
-        -Wno-unused-parameter
-        -Wunused-variable'
-      - LDFLAGS=-Wno-unused-command-line-argument
-
-  - &rubyspec
-    name: Check ruby/spec version guards on Ruby 2.4
-    language: ruby
-    rvm: 2.4.6
-    before_install:
-    install:
-    before_script: chmod -R u+w spec/ruby
-    # -j randomly hangs.
-    script: ruby -C spec/ruby ../mspec/bin/mspec .
-    after_failure:
-      - echo "ruby/spec failed on Ruby 2.4. This is likely because of a missing ruby_version_is guard, please add it. See spec/README.md."
-
-  - &baseruby
-    name: "BASERUBY: Ruby 1.9.3"
-    <<: *gcc-8
-    <<: *make-test-only
-    language: ruby
-    rvm: 1.9.3
-
-  - &dependency
-    name: Check dependencies in makefiles
-    language: ruby
-    before_install:
-    install:
-    before_script:
-      - |-
-        ruby -e 'new = []
-          Dir.glob("ext/**/extconf.rb") {|ex|
-            unless File.exist?(dep = File.dirname(ex)+"/depend")
-              puts "Adding "+dep
-              File.copy_stream("template/depend.tmpl", dep)
-              new << dep
-            end
-          }
-          exec("git", "add", *new) unless new.empty?'
-      - git diff --cached
-      - "> config.status"
-      - "> .rbconfig.time"
-      - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-      - make touch-unicode-files
-      - make -s $JOBS $UPDATE_UNICODE up
-      - make -s $JOBS srcs
-      - rm -f config.status Makefile rbconfig.rb .rbconfig.time
-      - $SETARCH ./configure -C --disable-install-doc --prefix=$RUBY_PREFIX --disable-rubygems 'optflags=-O0' 'debugflags=-save-temps=obj -g'
-      - ruby tool/update-deps --fix
-    script:
-      - git diff --no-ext-diff --ignore-submodules --exit-code
-    after_failure:
-      - echo "Dependencies need to update"
-    env:
-      - CONFIG_FLAG=
-
-matrix:
-  include:
-    # Build every commit:
-    - <<: *x86_64-linux
-    - <<: *i686-linux
-    - <<: *pedanticism
-    - <<: *assertions
-    - <<: *baseruby
-    - <<: *rubyspec
-    - <<: *dependency
-    # Build every commit (Allowed Failures):
-    - <<: *ASAN
-    - <<: *MSAN
-    - <<: *UBSAN
-    # Cron only:
-    - <<: *jemalloc
-    - <<: *VM_CHECK_MODE
-    - <<: *SUPPORT_JOKE
-    - <<: *WITH_COROUTINE_UCONTEXT
-    - <<: *WITH_COROUTINE_COPY
-    - <<: *TOKEN_THREADED_CODE
-    - <<: *CALL_THREADED_CODE
-    - <<: *NO_THREADED_CODE
-  allow_failures:
-    - name: -fsanitize=address
-    - name: -fsanitize=memory
-    - name: -fsanitize=undefined
-  fast_finish: true
-
-before_script:
-  - date # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
-  - echo JOBS=${JOBS} SETARCH=${SETARCH}
-  - $SETARCH uname -a
-  - $SETARCH uname -r
-  - rm -fr .ext autom4te.cache
-  - echo $TERM
-  - |-
-    [ -d ~/.downloaded-cache ] ||
-    mkdir ~/.downloaded-cache
-  - ln -s ~/.downloaded-cache
-  - "> config.status"
-  - "> .rbconfig.time"
-  - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-  - date; make touch-unicode-files
-  - date; make -s $JOBS $UPDATE_UNICODE up
-  - date; make -s $JOBS srcs
-  - rm -f config.status Makefile rbconfig.rb .rbconfig.time
-  - |-
-    if [ -d ~/config_2nd ]; then
-      cp -pr ~/config_2nd build
-    else
-      mkdir build
-    fi
-  - mkdir config_1st config_2nd
-  - chmod -R a-w .
-  - chmod -R u+w build config_1st config_2nd
-  - cd build
-  - ccache --show-stats
-  - |-
-    case "$CC" in
-    gcc*)   CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-diagnostics-color";;
-    clang*) CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-color-diagnostics";;
-    esac
-  - |-
-    [ ! -f config.cache ] ||
-    [ "$CC" = "`sed -n s/^ac_cv_prog_CC=//p config.cache`" ] ||
-    (set -x; exec rm config.cache)
-  - $SETARCH ../configure -C --disable-install-doc --prefix=$RUBY_PREFIX $CONFIG_FLAG
-  - cp -pr config.cache config.status .ext/include ../config_1st
-  - $SETARCH make reconfig
-  - cp -pr config.cache config.status .ext/include ../config_2nd
-  - (cd .. && exec diff -ru config_1st config_2nd)
-  - chmod u+w ..
-  - rm -rf ~/config_2nd
-  - mv ../config_2nd ~
-  - chmod u-w ..
-  - $SETARCH make -s $JOBS
-  - |-
-    date; : # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
-    if ! make install; then
-      if [ "$(uname)" = Darwin ]; then
-        # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
-        set -x
-        date
-        ./miniruby -e 'ARGV.map{|path|[path,File.stat(path)]}.sort_by{|path,st|st.mtime}.each{|path,st|p mtime:st.mtime.to_f, ctime:st.ctime.to_f, path:path}' .ext/.timestamp/.RUBYCOMMONDIR*time .ext/common/bigdecimal/*.rb ../ext/bigdecimal/lib/bigdecimal/*.rb . .. .ext .ext/common .ext/common/bigdecimal ext/bigdecimal ../ext ../ext/bigdecimal ../ext/bigdecimal/lib ../ext/bigdecimal/lib/bigdecimal
-        make COPY='cp -f' install
-      else
-        exit 1
-      fi
-    fi
-  - ccache --show-stats
-  - |-
-    [ -z "${GEMS_FOR_TEST}" ] ||
-    $RUBY_PREFIX/bin/gem install --no-document $GEMS_FOR_TEST
-  - echo "raise 'do not load ~/.irbrc in test'" > ~/.irbrc
-
-script:
-  - $SETARCH make -s test -o showflags TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
-  - travis_wait 50 $SETARCH make -s test-all -o exts TESTOPTS="${TESTOPTS} ${TEST_ALL_OPTS}" RUBYOPT="-w"
-  - $SETARCH make -s test-spec MSPECOPT=-ff # not using `-j` because sometimes `mspec -j` silently dies
-  - $SETARCH make -s -o showflags leaked-globals
-
-# Branch matrix.  Not all branches are Travis-ready so we limit branches here.
-branches:
-  only:
-    - master
-    - ruby_2_4
-    - ruby_2_5
-    - ruby_2_6
-
-# We want to be notified when something happens.
-notifications:
-  irc:
-    channels:
-      - "chat.freenode.net#ruby-core"
-    on_success: change # [always|never|change] # default: always
-    on_failure: always # [always|never|change] # default: always
-    template:
-      - "%{message} by @%{author}: See %{build_url}"
-
-  slack:
-    rooms:
-      - secure: ah7UEHBvncXT7bM5mvYIQAO+tIyV/wl7nXLb7wQD16dO2v8Gragy0mWjB79Q09hrrMGmp6H9bCDpdGS80boIA5EHaHoG4QaP0i9bsSt8U2AMWgZtfyIgQKJ4H2kXkGlrjO+AXTgnIkP7LNjdgAVUUTGQPb26T3QmoN2Splt+fIQ= # ruby:<token>#alerts
-    on_pull_requests: false
-    on_success: change
-    on_failure: always
-
-  email:
-    - ko1c-failure@atdot.net
diff --git a/BSDL b/BSDL
index a009caefea..66d93598aa 100644
--- a/BSDL
+++ b/BSDL
@@ -4,10 +4,10 @@ Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 1. Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
+   notice, this list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright
-notice, this list of conditions and the following disclaimer in the
-documentation and/or other materials provided with the distribution.
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
 
 THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ffdf2dd4b8..35e79dd3b9 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,4 +1 @@
-Please see the [official issue tracker] and wiki [HowToContribute].
-
-[official issue tracker]: https://bugs.ruby-lang.org
-[HowToContribute]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToContribute
+See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing/contributing_md.html), which includes setup and build instructions.
diff --git a/COPYING b/COPYING
index 48e5a96de7..428ce03ed7 100644
--- a/COPYING
+++ b/COPYING
@@ -1,3 +1,5 @@
+{日本語}[rdoc-ref:COPYING.ja]
+
 Ruby is copyrighted free software by Yukihiro Matsumoto <matz@netlab.jp>.
 You can redistribute it and/or modify it under either the terms of the
 2-clause BSDL (see the file BSDL), or the conditions below:
diff --git a/COPYING.ja b/COPYING.ja
index 230376bc60..5de2dbcc8f 100644
--- a/COPYING.ja
+++ b/COPYING.ja
@@ -1,3 +1,5 @@
+{English}[rdoc-ref:COPYING]
+
 本プログラムはフリーソフトウェアです．2-clause BSDL
 または以下に示す条件で本プログラムを再配布できます
 2-clause BSDLについてはBSDLファイルを参照して下さい．
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000000..2108276e72
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,766 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
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+version = "1.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
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+version = "2.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
+
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+ "capstone-sys",
+ "static_assertions",
+]
+
+[[package]]
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+version = "0.18.0"
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+checksum = "a4e8087cab6731295f5a2a2bd82989ba4f41d3a428aab2e7c98d8f4db38aac05"
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+
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+[[package]]
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+[[package]]
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+ "cpufeatures",
+ "rand_core",
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+ "encode_unicode",
+ "libc",
+ "windows-sys 0.61.2",
+]
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+ "libc",
+]
+
+[[package]]
+name = "encode_unicode"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
+
+[[package]]
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+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
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+ "windows-sys 0.52.0",
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+checksum = "e51093e27b0797c359783294ca4f0a911c270184cb10f85783b118614a1501be"
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+
+[[package]]
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+ "cfg-if",
+ "libc",
+ "r-efi",
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+version = "0.0.1"
+dependencies = [
+ "capstone",
+ "insta",
+ "jit",
+ "rand",
+ "yjit",
+]
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000000..33010e65fb
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,64 @@
+# This is the root Cargo [workspace](https://doc.rust-lang.org/cargo/reference/workspaces.html)
+# and the root package for all the rust code that are statically linked into ruby. Rust tooling
+# limitations means all Rust code need to share a single archive library (staticlib) at the
+# integration point with non-rust code. (See rustlang/rust#44322 and #104707 for a taste of
+# the linking challenges.)
+#
+# Do not add required dependencies. This is a policy that helps downstream consumers and give
+# us tight control over what we ship. All of the optional dependencies are used exclusively
+# during development.
+#
+# Release builds avoid Cargo entirely because offline builds can fail even when none of the
+# optional dependencies are built (rust-lang/cargo#10352).
+
+[workspace]
+members = ["zjit", "yjit", "jit"]
+
+[package]
+name = "ruby"
+version = "0.0.0"
+edition = "2024"
+rust-version = "1.85.0"
+publish = false # Don't publish to crates.io
+
+[dependencies]
+yjit = { path = "yjit", optional = true }
+zjit = { path = "zjit", optional = true }
+
+[lib]
+crate-type = ["staticlib"]
+path = "ruby.rs"
+
+[features]
+disasm = ["yjit?/disasm", "zjit?/disasm"]
+runtime_checks = ["yjit?/runtime_checks", "zjit?/runtime_checks"]
+yjit = [ "dep:yjit" ]
+zjit = [ "dep:zjit" ]
+
+[profile.dev]
+opt-level = 1 # On 0, functions use so much stack space that we get stray `SystemStackError`s
+debug = true
+debug-assertions = true
+overflow-checks = true
+
+[profile.test]
+inherits = "dev"
+opt-level = 0
+
+[profile.dev_nodebug]
+inherits = "dev"
+
+[profile.stats]
+inherits = "release"
+
+[profile.release]
+# NOTE: --enable-yjit and zjit builds use `rustc` without going through Cargo. You
+# might want to update the `rustc` invocation if you change this profile.
+opt-level = 3
+# The extra robustness that comes from checking for arithmetic overflow is
+# worth the performance cost for the compiler.
+overflow-checks = true
+# Generate debug info
+debug = true
+# Use ThinLTO. Much smaller output for a small amount of build time increase.
+lto = "thin"
diff --git a/LEGAL b/LEGAL
index 565c4c9cde..2777aa2c14 100644
--- a/LEGAL
+++ b/LEGAL
@@ -7,92 +7,118 @@ All the files in this distribution are covered under either the Ruby's
 license (see the file COPYING) or public-domain except some files
 mentioned below.
 
-ccan/build_assert/build_assert.h::
-ccan/check_type/check_type.h::
-ccan/container_of/container_of.h::
-ccan/str/str.h::
+[addr2line.c]
 
-  These files are licensed under the CC0.
+  A part of this file is from FreeBSD.
 
   >>>
-    https://creativecommons.org/choose/zero/
+    Copyright (c) 1986, 1988, 1991, 1993::
+    The Regents of the University of California.  All rights reserved.
 
-ccan/list/list.h::
+    (c) UNIX System Laboratories, Inc.
 
-  This file is licensed under the MIT License.
+    All or some portions of this file are derived from material licensed
+    to the University of California by American Telephone and Telegraph
+    Co. or Unix System Laboratories, Inc. and are reproduced herein with
+    the permission of UNIX System Laboratories, Inc.
 
-  >>>
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    4. Neither the name of the University nor the names of its contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
 
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
+    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
 
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
-include/ruby/onigmo.h::
-include/ruby/oniguruma.h::
-regcomp.c::
-regenc.c::
-regenc.h::
-regerror.c::
-regexec.c::
-regint.h::
-regparse.c::
-regparse.h::
-enc/ascii.c::
-enc/big5.c::
-enc/cp949.c::
-enc/emacs_mule.c::
-enc/encdb.c::
-enc/euc_jp.c::
-enc/euc_kr.c::
-enc/euc_tw.c::
-enc/gb18030.c::
-enc/gb2312.c::
-enc/gbk.c::
-enc/iso_8859_1.c::
-enc/iso_8859_10.c::
-enc/iso_8859_11.c::
-enc/iso_8859_13.c::
-enc/iso_8859_14.c::
-enc/iso_8859_15.c::
-enc/iso_8859_16.c::
-enc/iso_8859_2.c::
-enc/iso_8859_3.c::
-enc/iso_8859_4.c::
-enc/iso_8859_5.c::
-enc/iso_8859_6.c::
-enc/iso_8859_7.c::
-enc/iso_8859_8.c::
-enc/iso_8859_9.c::
-enc/koi8_r.c::
-enc/koi8_u.c::
-enc/shift_jis.c::
-enc/unicode.c::
-enc/us_ascii.c::
-enc/utf_16be.c::
-enc/utf_16le.c::
-enc/utf_32be.c::
-enc/utf_32le.c::
-enc/utf_8.c::
-enc/windows_1251.c::
+	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
+
+
+[ccan/build_assert/build_assert.h]
+[ccan/check_type/check_type.h]
+[ccan/container_of/container_of.h]
+[ccan/str/str.h]
+
+  These files are licensed under the {CC0}[https://creativecommons.org/choose/zero/].
+
+[ccan/list/list.h]
+
+  This file is licensed under the {MIT License}[rdoc-ref:@MIT+License].
+
+[coroutine]
+
+  Unless otherwise specified, these files are licensed under the
+  {MIT License}[rdoc-ref:@MIT+License].
+
+[include/ruby/onigmo.h]
+[include/ruby/oniguruma.h]
+[regcomp.c]
+[regenc.c]
+[regenc.h]
+[regerror.c]
+[regexec.c]
+[regint.h]
+[regparse.c]
+[regparse.h]
+[enc/ascii.c]
+[enc/big5.c]
+[enc/cp949.c]
+[enc/emacs_mule.c]
+[enc/encdb.c]
+[enc/euc_jp.c]
+[enc/euc_kr.c]
+[enc/euc_tw.c]
+[enc/gb18030.c]
+[enc/gb2312.c]
+[enc/gbk.c]
+[enc/iso_8859_1.c]
+[enc/iso_8859_10.c]
+[enc/iso_8859_11.c]
+[enc/iso_8859_13.c]
+[enc/iso_8859_14.c]
+[enc/iso_8859_15.c]
+[enc/iso_8859_16.c]
+[enc/iso_8859_2.c]
+[enc/iso_8859_3.c]
+[enc/iso_8859_4.c]
+[enc/iso_8859_5.c]
+[enc/iso_8859_6.c]
+[enc/iso_8859_7.c]
+[enc/iso_8859_8.c]
+[enc/iso_8859_9.c]
+[enc/koi8_r.c]
+[enc/koi8_u.c]
+[enc/shift_jis.c]
+[enc/unicode.c]
+[enc/us_ascii.c]
+[enc/utf_16be.c]
+[enc/utf_16le.c]
+[enc/utf_32be.c]
+[enc/utf_32le.c]
+[enc/utf_8.c]
+[enc/windows_1251.c]
+[enc/windows_31j.c]
 
   Onigmo (Oniguruma-mod) LICENSE
 
   >>>
-    Copyright (c) 2002-2009  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>  
-    Copyright (c) 2011-2014  K.Takata  <kentkt AT csc DOT jp>  
+    Copyright (c) 2002-2009::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    Copyright (c) 2011-2014::  K.Takata  <kentkt AT csc DOT jp>
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -119,7 +145,7 @@ enc/windows_1251.c::
   Oniguruma LICENSE
 
   >>>
-    Copyright (c) 2002-2009  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>  
+    Copyright (c) 2002-2009::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -150,10 +176,69 @@ enc/windows_1251.c::
     When this software is partly used or it is distributed with Ruby,
     this of Ruby follows the license of Ruby.
 
-enc/trans/GB/GB12345%UCS.src::
-enc/trans/GB/UCS%GB12345.src::
-enc/trans/GB/GB2312%UCS.src::
-enc/trans/GB/UCS%GB2312.src::
+[enc/windows_1250.c]
+[enc/windows_1252.c]
+
+  >>>
+    Copyright (c) 2006-2007::  Byte      <byte AT mail DOT kna DOT ru>
+                               K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[enc/cesu_8.c]
+[enc/windows_1253.c]
+[enc/windows_1254.c]
+[enc/windows_1257.c]
+
+  >>>
+    Copyright (c) 2002-2007::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[enc/trans/GB/GB12345%UCS.src]
+[enc/trans/GB/UCS%GB12345.src]
+[enc/trans/GB/GB2312%UCS.src]
+[enc/trans/GB/UCS%GB2312.src]
 
   These files have this explanatory texts.
 
@@ -165,12 +250,12 @@ enc/trans/GB/UCS%GB2312.src::
     files for any particular purpose, and has ceased to publish the files many
     years ago.
 
-enc/trans/JIS/JISX0201-KANA%UCS.src::
-enc/trans/JIS/JISX0208\@1990%UCS.src::
-enc/trans/JIS/JISX0212%UCS.src::
-enc/trans/JIS/UCS%JISX0201-KANA.src::
-enc/trans/JIS/UCS%JISX0208@1990.src::
-enc/trans/JIS/UCS%JISX0212.src::
+[enc/trans/JIS/JISX0201-KANA%UCS.src]
+[enc/trans/JIS/JISX0208\@1990%UCS.src]
+[enc/trans/JIS/JISX0212%UCS.src]
+[enc/trans/JIS/UCS%JISX0201-KANA.src]
+[enc/trans/JIS/UCS%JISX0208@1990.src]
+[enc/trans/JIS/UCS%JISX0212.src]
 
   These files are copyrighted as the following.
 
@@ -179,49 +264,64 @@ enc/trans/JIS/UCS%JISX0212.src::
 
     For terms of use, see http://www.unicode.org/terms_of_use.html
 
-enc/trans/JIS/JISX0213-1%UCS@BMP.src::
-enc/trans/JIS/JISX0213-1%UCS@SIP.src::
-enc/trans/JIS/JISX0213-2%UCS@BMP.src::
-enc/trans/JIS/JISX0213-2%UCS@SIP.src::
+[enc/trans/JIS/JISX0213-1%UCS@BMP.src]
+[enc/trans/JIS/JISX0213-1%UCS@SIP.src]
+[enc/trans/JIS/JISX0213-2%UCS@BMP.src]
+[enc/trans/JIS/JISX0213-2%UCS@SIP.src]
 
   These files are copyrighted as the following.
 
   >>>
-    Copyright (C) 2001 earthian@tama.or.jp, All Rights Reserved.  
-    Copyright (C) 2001 I'O, All Rights Reserved.  
-    Copyright (C) 2006 Project X0213, All Rights Reserved.  
+    Copyright (C) 2001:: earthian@tama.or.jp, All Rights Reserved.
+    Copyright (C) 2001:: I'O, All Rights Reserved.
+    Copyright (C) 2006:: Project X0213, All Rights Reserved.
     You can use, modify, distribute this table freely.
 
-enc/trans/JIS/UCS@BMP%JISX0213-1.src::
-enc/trans/JIS/UCS@BMP%JISX0213-2.src::
-enc/trans/JIS/UCS@SIP%JISX0213-1.src::
-enc/trans/JIS/UCS@SIP%JISX0213-2.src::
+[enc/trans/JIS/UCS@BMP%JISX0213-1.src]
+[enc/trans/JIS/UCS@BMP%JISX0213-2.src]
+[enc/trans/JIS/UCS@SIP%JISX0213-1.src]
+[enc/trans/JIS/UCS@SIP%JISX0213-2.src]
 
   These files are copyrighted as the following.
 
   >>>
-    Copyright (C) 2001 earthian@tama.or.jp, All Rights Reserved.  
-    Copyright (C) 2001 I'O, All Rights Reserved.  
+    Copyright (C) 2001:: earthian@tama.or.jp, All Rights Reserved.
+    Copyright (C) 2001:: I'O, All Rights Reserved.
     You can use, modify, distribute this table freely.
 
-configure::
+[enc/trans/ucm/glibc-BIG5-2.3.3.ucm]
+[enc/trans/ucm/glibc-BIG5HKSCS-2.3.3.ucm]
+
+  >>>
+    Copyright (C) 2001-2005:: International Business Machines
+                              Corporation and others.  All Rights Reserved.
+
+[enc/trans/ucm/windows-950-2000.ucm]
+[enc/trans/ucm/windows-950_hkscs-2001.ucm]
+
+  >>>
+    Copyright (C) 2001-2002:: International Business Machines
+                              Corporation and others.  All Rights Reserved.
+
+
+[configure]
 
   This file is free software.
 
   >>>
-    Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+    Copyright (C) 1992-1996, 1998-2012:: Free Software Foundation, Inc.
 
     This configure script is free software; the Free Software Foundation
     gives unlimited permission to copy, distribute and modify it.
 
-tool/config.guess::
-tool/config.sub::
+[tool/config.guess]
+[tool/config.sub]
 
   As long as you distribute these files with the file configure, they
   are covered under the Ruby's license.
 
   >>>
-    Copyright 1992-2018 Free Software Foundation, Inc.
+    Copyright 1992-2018:: Free Software Foundation, Inc.
 
     This file is free software; you can redistribute it and/or modify it
     under the terms of the GNU General Public License as published by
@@ -243,14 +343,43 @@ tool/config.sub::
     program.  This Exception is an additional permission under section 7
     of the GNU General Public License, version 3 ("GPLv3").
 
-parse.c::
+[tool/lib/test/*]
+[tool/lib/core_assertions.rb]
+
+  Some of methods on these files are based on MiniTest 4. MiniTest 4 is
+  distributed under the MIT License.
 
-  This file is licensed under the GPL, but is incorporated into Ruby and
+  >>>
+    Copyright (c) Ryan Davis, seattle.rb
+
+    Permission is hereby granted, free of charge, to any person obtaining
+    a copy of this software and associated documentation files (the
+    'Software'), to deal in the Software without restriction, including
+    without limitation the rights to use, copy, modify, merge, publish,
+    distribute, sublicense, and/or sell copies of the Software, and to
+    permit persons to whom the Software is furnished to do so, subject to
+    the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+[parse.c]
+[parse.h]
+
+  These files are licensed under the GPL, but are incorporated into Ruby and
   redistributed under the terms of the Ruby license, as permitted by the
   exception to the GPL below.
 
   >>>
-    Copyright (C) 1984, 1989-1990, 2000-2015, 2018 Free Software Foundation, Inc.
+    Copyright (C) 1984, 1989-1990, 2000-2015, 2018:: Free Software Foundation, Inc.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -278,12 +407,12 @@ parse.c::
     This special exception was added by the Free Software Foundation in
     version 2.2 of Bison.
 
-missing/dtoa.c::
+[missing/dtoa.c]
 
   This file is under these licenses.
 
   >>>
-    Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
+    Copyright (c) 1991, 2000, 2001:: by Lucent Technologies.
 
     Permission to use, copy, modify, and distribute this software for any
     purpose without fee is hereby granted, provided that this entire notice
@@ -297,8 +426,8 @@ missing/dtoa.c::
     OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
 
   >>>
-    Copyright (c) 2004-2008 David Schultz <das@FreeBSD.ORG>  
-    All rights reserved.
+    Copyright (c) 2004-2008:: David Schultz <das@FreeBSD.ORG>
+                              All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -321,32 +450,34 @@ missing/dtoa.c::
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-win32/win32.{c,h}::
+[win32/win32.c]
+[include/ruby/win32.h]
 
   You can apply the Artistic License to these files. (or GPL,
   alternatively)
 
   >>>
-    Copyright (c) 1993, Intergraph Corporation
+    Copyright (c) 1993:: Intergraph Corporation
 
     You may distribute under the terms of either the GNU General Public
     License or the Artistic License, as specified in the perl README file.
 
-missing/mt19937.c::
+[missing/mt19937.c]
 
   This file is under the new-style BSD license.
 
   >>>
-    A C-program for MT19937, with initialization improved 2002/2/10.
-    Coded by Takuji Nishimura and Makoto Matsumoto.  
+    A C-program for MT19937, with initialization improved 2002/2/10.::
+    Coded by Takuji Nishimura and Makoto Matsumoto.
+
     This is a faster version by taking Shawn Cokus's optimization,
     Matthe Bellew's simplification, Isaku Wada's real version.
 
     Before using, initialize the state by using init_genrand(seed)
     or init_by_array(init_key, key_length).
 
-    Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
-    All rights reserved.
+    Copyright (C) 1997 - 2002:: Makoto Matsumoto and Takuji Nishimura,
+                                All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -382,13 +513,13 @@ missing/mt19937.c::
 
   The Wayback Machine url: http://web.archive.org/web/19990429082237/http://www.math.keio.ac.jp/matumoto/emt.html
 
-missing/procstat_vm.c::
+[missing/procstat_vm.c]
 
   This file is under the new-style BSD license.
 
   >>>
-    Copyright (c) 2007 Robert N. M. Watson  
-    All rights reserved.
+    Copyright (c) 2007:: Robert N. M. Watson
+                         All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -413,151 +544,65 @@ missing/procstat_vm.c::
 
     $FreeBSD: head/usr.bin/procstat/procstat_vm.c 261780 2014-02-11 21:57:37Z jhb $
 
-vsnprintf.c::
+[vsnprintf.c]
 
-  This file is under the old-style BSD license.  Note that the
-  paragraph 3 below is now null and void.
+  This file is under the {old-style BSD license}[rdoc-ref:@Old-style+BSD+license].
 
   >>>
-    Copyright (c) 1990, 1993  
+    Copyright (c) 1990, 1993::
     The Regents of the University of California.  All rights reserved.
 
     This code is derived from software contributed to Berkeley by
     Chris Torek.
 
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    3. Neither the name of the University nor the names of its contributors
-       may be used to endorse or promote products derived from this software
-       without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-    SUCH DAMAGE.
-
-    IMPORTANT NOTE:
-    --------------
-    From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
-    paragraph 3 above is now null and void.
-
-st.c::
-strftime.c::
-include/ruby/st.h::
-missing/acosh.c::
-missing/alloca.c::
-missing/dup2.c::
-missing/erf.c::
-missing/finite.c::
-missing/hypot.c::
-missing/isinf.c::
-missing/isnan.c::
-missing/lgamma_r.c::
-missing/memcmp.c::
-missing/memmove.c::
-missing/strchr.c::
-missing/strerror.c::
-missing/strstr.c::
-missing/tgamma.c::
-ext/date/date_strftime.c::
-ext/digest/sha1/sha1.c::
-ext/digest/sha1/sha1.h::
-ext/sdbm/_sdbm.c::
-ext/sdbm/sdbm.h::
+[st.c]
+[strftime.c]
+[include/ruby/st.h]
+[missing/acosh.c]
+[missing/alloca.c]
+[missing/erf.c]
+[missing/hypot.c]
+[missing/lgamma_r.c]
+[missing/memcmp.c]
+[missing/memmove.c]
+[missing/strchr.c]
+[missing/strerror.c]
+[missing/strstr.c]
+[missing/tgamma.c]
+[ext/date/date_strftime.c]
+[ext/digest/sha1/sha1.c]
+[ext/digest/sha1/sha1.h]
 
   These files are all under public domain.
 
-missing/crypt.c::
+[missing/crypt.c]
 
-  This file is under the old-style BSD license.  Note that the
-  paragraph 3 below is now null and void.
+  This file is under the {old-style BSD license}[rdoc-ref:@Old-style+BSD+license].
 
   >>>
-    Copyright (c) 1989, 1993  
+    Copyright (c) 1989, 1993::
     The Regents of the University of California.  All rights reserved.
 
     This code is derived from software contributed to Berkeley by
     Tom Truscott.
 
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    3. Neither the name of the University nor the names of its contributors
-       may be used to endorse or promote products derived from this software
-       without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-    SUCH DAMAGE.
+[missing/setproctitle.c]
 
-missing/setproctitle.c::
-
-  This file is under the old-style BSD license.  Note that the
-  paragraph 3 below is now null and void.
+  This file is under the {old-style BSD license}[rdoc-ref:@Old-style+BSD+license].
 
   >>>
-    Copyright 2003 Damien Miller  
-    Copyright (c) 1983, 1995-1997 Eric P. Allman  
-    Copyright (c) 1988, 1993  
+    Copyright 2003:: Damien Miller
+    Copyright (c) 1983, 1995-1997:: Eric P. Allman
+    Copyright (c) 1988, 1993::
     The Regents of the University of California.  All rights reserved.
 
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    3. Neither the name of the University nor the names of its contributors
-       may be used to endorse or promote products derived from this software
-       without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-    SUCH DAMAGE.
-
-missing/strlcat.c::
-missing/strlcpy.c::
+[missing/strlcat.c]
+[missing/strlcpy.c]
 
   These files are under an ISC-style license.
 
   >>>
-    Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+    Copyright (c) 1998, 2015:: Todd C. Miller <Todd.Miller@courtesan.com>
 
     Permission to use, copy, modify, and distribute this software for any
     purpose with or without fee is hereby granted, provided that the above
@@ -571,26 +616,26 @@ missing/strlcpy.c::
     ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-missing/langinfo.c::
+[missing/langinfo.c]
 
   This file is from http://www.cl.cam.ac.uk/~mgk25/ucs/langinfo.c.
   Ruby uses a modified version. The file contains the following
   author/copyright notice:
 
   >>>
-    Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11  
+    Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11::
     Permission to use, copy, modify, and distribute this software
     for any purpose and without fee is hereby granted. The author
     disclaims all warranties with regard to this software.
 
-ext/digest/md5/md5.c::
-ext/digest/md5/md5.h::
+[ext/digest/md5/md5.c]
+[ext/digest/md5/md5.h]
 
   These files are under the following license.  Ruby uses modified
   versions of them.
 
   >>>
-    Copyright (C) 1999, 2000 Aladdin Enterprises.  All rights reserved.
+    Copyright (C) 1999, 2000:: Aladdin Enterprises.  All rights reserved.
 
     This software is provided 'as-is', without any express or implied
     warranty.  In no event will the authors be held liable for any damages
@@ -611,8 +656,8 @@ ext/digest/md5/md5.h::
     L. Peter Deutsch
     ghost@aladdin.com
 
-ext/digest/rmd160/rmd160.c::
-ext/digest/rmd160/rmd160.h::
+[ext/digest/rmd160/rmd160.c]
+[ext/digest/rmd160/rmd160.h]
 
   These files have the following copyright information, and by the
   author we are allowed to use it under the new-style BSD license.
@@ -622,16 +667,16 @@ ext/digest/rmd160/rmd160.h::
               (Arranged for libc by Todd C. Miller)
     DATE::    1 March 1996
 
-    Copyright (c) Katholieke Universiteit Leuven
+    Copyright (c):: Katholieke Universiteit Leuven
     1996, All Rights Reserved
 
-ext/digest/sha2/sha2.c::
-ext/digest/sha2/sha2.h::
+[ext/digest/sha2/sha2.c]
+[ext/digest/sha2/sha2.h]
 
   These files are under the new-style BSD license.
 
   >>>
-    Copyright 2000 Aaron D. Gifford.  All rights reserved.
+    Copyright 2000:: Aaron D. Gifford.  All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -657,57 +702,30 @@ ext/digest/sha2/sha2.h::
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-ext/json/generator/generator.c::
-
-  The file contains the following copyright notice.
-
-  >>>
-    Copyright 2001-2004 Unicode, Inc.
-
-    Disclaimer::
+[ext/json/vendor/fpconv.c]
 
-      This source code is provided as is by Unicode, Inc. No claims are
-      made as to fitness for any particular purpose. No warranties of any
-      kind are expressed or implied. The recipient agrees to determine
-      applicability of information provided. If this file has been
-      purchased on magnetic or optical media from Unicode, Inc., the
-      sole remedy for any claim will be exchange of defective media
-      within 90 days of receipt.
+  This file is under the {Boost Software License}[rdoc-ref:@Boost+Software+License+1.0].
 
-    Limitations on Rights to Redistribute This Code::
-
-      Unicode, Inc. hereby grants the right to freely use the information
-      supplied in this file in the creation of products supporting the
-      Unicode Standard, and to make copies of this file in any form
-      for internal or external distribution as long as this notice
-      remains attached.
-
-ext/nkf/nkf-utf8/config.h::
-ext/nkf/nkf-utf8/nkf.c::
-ext/nkf/nkf-utf8/utf8tbl.c::
-
-  These files are under the following license.  So to speak, it is
-  copyrighted semi-public-domain software.
+[ext/json/vendor/jeaiii-ltoa.h]
 
   >>>
-    Copyright (C) 1987, Fujitsu LTD. (Itaru ICHIKAWA)
+    Copyright (c) 2024,2025 Enrico Thierbach - https://github.com/radiospiel
+    Copyright (c) 2022 James Edward Anhalt III - https://github.com/jeaiii/itoa
 
-    Everyone is permitted to do anything on this program
-    including copying, modifying, improving,
-    as long as you don't try to pretend that you wrote it.
-    i.e., the above copyright notice has to appear in all copies.
-    Binary distribution requires original version messages.
-    You don't have to ask before copying, redistribution or publishing.
-    THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE.
+    {MIT License}[rdoc-ref:@MIT+License]
 
-ext/psych::
-test/psych::
+[ext/json/vendor/ryu.h]
+  This file is adapted from the Ryu algorithm by Ulf Adams https://github.com/ulfjack/ryu.
+  It is dual-licensed under {Apache License 2.0}[rdoc-ref:@Apache+License+2.0] OR
+  {Boost Software License 1.0}[rdoc-ref:@Boost+Software+License+1.0].
 
-  The files under these directories are under the following license, except for
-  ext/psych/yaml.
+[ext/psych]
+[test/psych]
+
+  The files under these directories are under the following license.
 
   >>>
-    Copyright 2009 Aaron Patterson, et al.
+    Copyright 2009:: Aaron Patterson, et al.
 
     Permission is hereby granted, free of charge, to any person obtaining a copy of
     this software and associated documentation files (the 'Software'), to deal in
@@ -727,39 +745,28 @@ test/psych::
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.
 
-ext/psych/yaml::
-
-  The files under this directory are under the following license.
+[ext/pty/pty.c]
 
   >>>
-    Copyright (c) 2006 Kirill Simonov
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy of
-    this software and associated documentation files (the "Software"), to deal in
-    the Software without restriction, including without limitation the rights to
-    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-    of the Software, and to permit persons to whom the Software is furnished to do
-    so, subject to the following conditions:
+    C) Copyright 1998:: by Akinori Ito.
 
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
+    This software may be redistributed freely for this purpose, in full
+    or in part, provided that this entire copyright notice is included
+    on any copies of this software and applications and derivations thereof.
 
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-    SOFTWARE.
+    This software is provided on an "as is" basis, without warranty of any
+    kind, either expressed or implied, as to any matter including, but not
+    limited to warranty of fitness of purpose, or merchantability, or
+    results obtained from use of this software.
 
-ext/socket/addrinfo.h::
-ext/socket/getaddrinfo.c::
-ext/socket/getnameinfo.c::
+[ext/socket/addrinfo.h]
+[ext/socket/getaddrinfo.c]
+[ext/socket/getnameinfo.c]
 
   These files are under the new-style BSD license.
 
   >>>
-    Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project.
+    Copyright (C) 1995, 1996, 1997, 1998, and 1999:: WIDE Project.
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -786,16 +793,16 @@ ext/socket/getnameinfo.c::
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-ext/win32ole/win32ole.c::
+[ext/win32ole/win32ole.c]
 
   You can apply the Artistic License to this file. (or GPL,
   alternatively)
 
   >>>
-    (c) 1995 Microsoft Corporation. All rights reserved.
+    (c) 1995:: Microsoft Corporation. All rights reserved.
     Developed by ActiveWare Internet Corp., http://www.ActiveWare.com
 
-    Other modifications Copyright (c) 1997, 1998 by Gurusamy Sarathy
+    Other modifications Copyright (c) 1997, 1998:: by Gurusamy Sarathy
     <gsar@umich.edu> and Jan Dubois <jan.dubois@ibm.net>
 
     You may distribute under the terms of either the GNU General Public
@@ -804,20 +811,17 @@ ext/win32ole/win32ole.c::
 
   The Wayback Machine url: http://web.archive.org/web/19970607104352/http://www.activeware.com:80/
 
-lib/rdoc/generator/template/darkfish/css/fonts.css::
-
-  This file is licensed under the SIL Open Font License.
+[lib/rdoc/generator/template/darkfish/css/fonts.css]
 
-  >>>
-    http://scripts.sil.org/OFL
+  This file is licensed under the {SIL Open Font License}[http://scripts.sil.org/OFL].
 
-spec/mspec::
-spec/ruby::
+[spec/mspec]
+[spec/ruby]
 
   The files under these directories are under the following license.
 
   >>>
-    Copyright (c) 2008 Engine Yard, Inc. All rights reserved.
+    Copyright (c) 2008:: Engine Yard, Inc. All rights reserved.
 
     Permission is hereby granted, free of charge, to any person
     obtaining a copy of this software and associated documentation
@@ -840,17 +844,17 @@ spec/ruby::
     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     OTHER DEALINGS IN THE SOFTWARE.
 
-lib/rubygems.rb::
-lib/rubygems::
-test/rubygems::
+[lib/rubygems.rb]
+[lib/rubygems]
+[test/rubygems]
 
   RubyGems is under the following license.
 
   >>>
     RubyGems is copyrighted free software by Chad Fowler, Rich Kilmer, Jim
     Weirich and others.  You can redistribute it and/or modify it under
-    either the terms of the MIT license (see the file MIT.txt), or the
-    conditions below:
+    either the terms of the {MIT license}[rdoc-ref:@MIT+License], or the conditions
+    below:
 
     1. You may make and give away verbatim copies of the source form of the
        software without restriction, provided that you duplicate all of the
@@ -901,20 +905,117 @@ test/rubygems::
        WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
        PURPOSE.
 
-lib/bundler::
-lib/bundler.rb::
-lib/bundler.gemspec::
-spec/bundler::
-man/bundle-*,gemfile.*::
+[lib/bundler]
+[lib/bundler.rb]
+[spec/bundler]
 
   Bundler is under the following license.
 
   >>>
-    Portions copyright (c) 2010 Andre Arko  
-    Portions copyright (c) 2009 Engine Yard  
+    Portions copyright (c) 2010:: Andre Arko
+    Portions copyright (c) 2009:: Engine Yard
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[lib/bundler/vendor/thor]
+
+  Thor is under the following license.
+
+  >>>
+    Copyright (c) 2008 Yehuda Katz, Eric Hodel, et al.
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[lib/rubygems/vendor/molinillo]
+
+  molinillo is under the following license.
+
+  >>>
+    Copyright (c) 2014 Samuel E. Giddins segiddins@segiddins.me
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[lib/bundler/vendor/pub_grub]
+
+  pub_grub is under the following license.
+
+  >>>
+    Copyright (c) 2018 John Hawthorn
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[lib/bundler/vendor/connection_pool]
+
+  connection_pool is under the following license.
+
+  >>>
+    Copyright (c) 2011 Mike Perham
 
-    MIT License::
+    {MIT License}[rdoc-ref:@MIT+License]
 
+[lib/bundler/vendor/net-http-persistent]
+
+  net-http-persistent is under the following license.
+
+  >>>
+    Copyright (c) Eric Hodel, Aaron Patterson
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[lib/did_you_mean]
+[lib/did_you_mean.rb]
+[test/did_you_mean]
+
+  did_you_mean is under the following license.
+
+  >>>
+    Copyright (c) 2014-2016 Yuki Nishijima
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[lib/error_highlight]
+[lib/error_highlight.rb]
+[test/error_highlight]
+
+  error_highlight is under the following license.
+
+  >>>
+    Copyright (c) 2021 Yusuke Endoh
+
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[benchmark/so_ackermann.rb]
+[benchmark/so_array.rb]
+[benchmark/so_binary_trees.rb]
+[benchmark/so_concatenate.rb]
+[benchmark/so_count_words.yml]
+[benchmark/so_exception.rb]
+[benchmark/so_fannkuch.rb]
+[benchmark/so_fasta.rb]
+[benchmark/so_k_nucleotide.yml]
+[benchmark/so_lists.rb]
+[benchmark/so_mandelbrot.rb]
+[benchmark/so_matrix.rb]
+[benchmark/so_meteor_contest.rb]
+[benchmark/so_nbody.rb]
+[benchmark/so_nested_loop.rb]
+[benchmark/so_nsieve.rb]
+[benchmark/so_nsieve_bits.rb]
+[benchmark/so_object.rb]
+[benchmark/so_partial_sums.rb]
+[benchmark/so_pidigits.rb]
+[benchmark/so_random.rb]
+[benchmark/so_reverse_complement.yml]
+[benchmark/so_sieve.rb]
+[benchmark/so_spectralnorm.rb]
+
+  These files are very old copy of then-called "The Great Computer Language
+  Shootout".  LEGAL SITUATION OF THESE FILES ARE UNCLEAR because the original
+  site has been lost.  Upstream diverged to delete several benchmarks listed
+  above.
+
+== MIT License
+>>>
       Permission is hereby granted, free of charge, to any person obtaining
       a copy of this software and associated documentation files (the
       "Software"), to deal in the Software without restriction, including
@@ -933,3 +1034,267 @@ man/bundle-*,gemfile.*::
       LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
       OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
       WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+== Old-style BSD license
+>>>
+      Redistribution and use in source and binary forms, with or without
+      modification, are permitted provided that the following conditions
+      are met:
+      1. Redistributions of source code must retain the above copyright
+         notice, this list of conditions and the following disclaimer.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, this list of conditions and the following disclaimer in the
+         documentation and/or other materials provided with the distribution.
+      3. Neither the name of the University nor the names of its contributors
+         may be used to endorse or promote products derived from this software
+         without specific prior written permission.
+
+      THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+      ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+      IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+      ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+      FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+      DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+      OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+      HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+      LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+      OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+      SUCH DAMAGE.
+
+      IMPORTANT NOTE::
+
+      From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
+      paragraph 3 above is now null and void.
+
+== Boost Software License 1.0
+
+>>>
+      Boost Software License - Version 1.0 - August 17th, 2003
+
+      Permission is hereby granted, free of charge, to any person or organization
+      obtaining a copy of the software and accompanying documentation covered by
+      this license (the "Software") to use, reproduce, display, distribute,
+      execute, and transmit the Software, and to prepare derivative works of the
+      Software, and to permit third-parties to whom the Software is furnished to
+      do so, all subject to the following:
+
+      The copyright notices in the Software and this entire statement, including
+      the above license grant, this restriction and the following disclaimer,
+      must be included in all copies of the Software, in whole or in part, and
+      all derivative works of the Software, unless such copies or derivative
+      works are solely in the form of machine-executable object code generated by
+      a source language processor.
+
+      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+      IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+      FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+      SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+      FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+      ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+      DEALINGS IN THE SOFTWARE.
+
+== Apache License 2.0
+
+>>>
+      Apache License
+      Version 2.0, January 2004
+      http://www.apache.org/licenses/
+
+      TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+      1. Definitions.
+
+         "License" shall mean the terms and conditions for use, reproduction,
+         and distribution as defined by Sections 1 through 9 of this document.
+
+         "Licensor" shall mean the copyright owner or entity authorized by
+         the copyright owner that is granting the License.
+
+         "Legal Entity" shall mean the union of the acting entity and all
+         other entities that control, are controlled by, or are under common
+         control with that entity. For the purposes of this definition,
+         "control" means (i) the power, direct or indirect, to cause the
+         direction or management of such entity, whether by contract or
+         otherwise, or (ii) ownership of fifty percent (50%) or more of the
+         outstanding shares, or (iii) beneficial ownership of such entity.
+
+         "You" (or "Your") shall mean an individual or Legal Entity
+         exercising permissions granted by this License.
+
+         "Source" form shall mean the preferred form for making modifications,
+         including but not limited to software source code, documentation
+         source, and configuration files.
+
+         "Object" form shall mean any form resulting from mechanical
+         transformation or translation of a Source form, including but
+         not limited to compiled object code, generated documentation,
+         and conversions to other media types.
+
+         "Work" shall mean the work of authorship, whether in Source or
+         Object form, made available under the License, as indicated by a
+         copyright notice that is included in or attached to the work
+         (an example is provided in the Appendix below).
+
+         "Derivative Works" shall mean any work, whether in Source or Object
+         form, that is based on (or derived from) the Work and for which the
+         editorial revisions, annotations, elaborations, or other modifications
+         represent, as a whole, an original work of authorship. For the purposes
+         of this License, Derivative Works shall not include works that remain
+         separable from, or merely link (or bind by name) to the interfaces of,
+         the Work and Derivative Works thereof.
+
+         "Contribution" shall mean any work of authorship, including
+         the original version of the Work and any modifications or additions
+         to that Work or Derivative Works thereof, that is intentionally
+         submitted to Licensor for inclusion in the Work by the copyright owner
+         or by an individual or Legal Entity authorized to submit on behalf of
+         the copyright owner. For the purposes of this definition, "submitted"
+         means any form of electronic, verbal, or written communication sent
+         to the Licensor or its representatives, including but not limited to
+         communication on electronic mailing lists, source code control systems,
+         and issue tracking systems that are managed by, or on behalf of, the
+         Licensor for the purpose of discussing and improving the Work, but
+         excluding communication that is conspicuously marked or otherwise
+         designated in writing by the copyright owner as "Not a Contribution."
+
+         "Contributor" shall mean Licensor and any individual or Legal Entity
+         on behalf of whom a Contribution has been received by Licensor and
+         subsequently incorporated within the Work.
+
+      2. Grant of Copyright License. Subject to the terms and conditions of
+         this License, each Contributor hereby grants to You a perpetual,
+         worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+         copyright license to reproduce, prepare Derivative Works of,
+         publicly display, publicly perform, sublicense, and distribute the
+         Work and such Derivative Works in Source or Object form.
+
+      3. Grant of Patent License. Subject to the terms and conditions of
+         this License, each Contributor hereby grants to You a perpetual,
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+             notices within Derivative Works that You distribute, alongside
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+
+         You may add Your own copyright statement to Your modifications and
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+         for any such Derivative Works as a whole, provided Your use,
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+         the conditions stated in this License.
+
+      5. Submission of Contributions. Unless You explicitly state otherwise,
+         any Contribution intentionally submitted for inclusion in the Work
+         by You to the Licensor shall be under the terms and conditions of
+         this License, without any additional terms or conditions.
+         Notwithstanding the above, nothing herein shall supersede or modify
+         the terms of any separate license agreement you may have executed
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+
+      6. Trademarks. This License does not grant permission to use the trade
+         names, trademarks, service marks, or product names of the Licensor,
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+         agreed to in writing, Licensor provides the Work (and each
+         Contributor provides its Contributions) on an "AS IS" BASIS,
+         WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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+      8. Limitation of Liability. In no event and under no legal theory,
+         whether in tort (including negligence), contract, or otherwise,
+         unless required by applicable law (such as deliberate and grossly
+         negligent acts) or agreed to in writing, shall any Contributor be
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+
+      END OF TERMS AND CONDITIONS
+
+      APPENDIX: How to apply the Apache License to your work.
+
+      >>>
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+         boilerplate notice, with the fields enclosed by brackets "[]"
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+         same "printed page" as the copyright notice for easier
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+      Copyright [yyyy] [name of copyright owner]
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+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
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diff --git a/NEWS b/NEWS
deleted file mode 100644
index 958385f6f9..0000000000
--- a/NEWS
+++ /dev/null
@@ -1,464 +0,0 @@
-# -*- rdoc -*-
-
-= NEWS for Ruby 2.7.0
-
-This document is a list of user visible feature changes made between
-releases except for bug fixes.
-
-Note that each entry is kept so brief that no reason behind or reference
-information is supplied with.  For a full list of changes with all
-sufficient information, see the ChangeLog file or Redmine
-(e.g. <tt>https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER</tt>)
-
-== Changes since the 2.6.0 release
-
-=== Language changes
-
-* Pattern matching is introduced as an experimental feature. [Feature #14912]
-
-* Method reference operator, <code>.:</code> is introduced as an
-  experimental feature.  [Feature #12125] [Feature #13581]
-
-* Automatic conversion of keyword arguments and positional arguments is
-  deprecated, and conversion will be removed in Ruby 3.  [Feature #14183]
-
-  * When a method call passes a Hash at the last argument, and when it
-    passes no keywords, and when the called method accepts keywords, a
-    warning is emitted.  To continue treating as keywords, add a double
-    splat operator to avoid the warning and ensure correct behavior in
-    Ruby 3.
-
-     def foo(key: 42); end; foo({key: 42})   # warned
-     def foo(**kw);    end; foo({key: 42})   # warned
-     def foo(key: 42); end; foo(**{key: 42}) # OK
-     def foo(**kw);    end; foo(**{key: 42}) # OK
-
-  * When a method call passes keywords to a method that accepts keywords,
-    but it does not pass enough required positional arguments, the
-    keywords are treated as a final required positional argument, and a
-    warning is emitted.  Pass the argument as a hash instead of keywords
-    to avoid the warning and ensure correct behavior in Ruby 3.
-
-     def foo(h, **kw); end; foo(key: 42)      # warned
-     def foo(h, key: 42); end; foo(key: 42)   # warned
-     def foo(h, **kw); end; foo({key: 42})    # OK
-     def foo(h, key: 42); end; foo({key: 42}) # OK
-
-  * When a method accepts specific keywords but not a keyword splat, and
-    a hash or keywords splat is passed to the method that includes both
-    Symbol and non-Symbol keys, the hash will continue to be split, and
-    a warning will be emitted.  You will need to update the calling code
-    to pass separate hashes to ensure correct behavior in Ruby 3.
-
-     def foo(h={}, key: 42); end; foo("key" => 43, key: 42)   # warned
-     def foo(h={}, key: 42); end; foo({"key" => 43, key: 42}) # warned
-     def foo(h={}, key: 42); end; foo({"key" => 43}, key: 42) # OK
-     def foo(h={}, key: 42); end; foo({"key" => 43}, key: 42) # OK
-
-  * If a method does not accept keywords, and is called with keywords,
-    the keywords are still treated as a positional hash, with no warning.
-    This behavior will continue to work in Ruby 3.
-
-     def foo(opt={});  end; foo( key: 42 )   # OK
-
-* Non-symbols are allowed as a keyword argument keys if method accepts
-  arbitrary keywords. [Feature #14183]
-
-   def foo(**kw); p kw; end; foo("str" => 1) #=> {"str"=>1}
-
-* <code>**nil</code> is allowed in method definitions to explicitly mark
-  that the method accepts no keywords. Calling such a method with keywords
-  will result in an ArgumentError. [Feature #14183]
-
-   def foo(h, **nil); end; foo(key: 1)       # ArgumentError
-   def foo(h, **nil); end; foo(**{key: 1})   # ArgumentError
-   def foo(h, **nil); end; foo("str" => 1)   # ArgumentError
-   def foo(h, **nil); end; foo({key: 1})     # OK
-   def foo(h, **nil); end; foo({"str" => 1}) # OK
-
-* Passing an empty keyword splat to a method that does not accept keywords
-  no longer passes an empty hash, unless the empty hash is necessary for
-  a required parameter, in which case a warning will be emitted.  Remove
-  the double splat to continue passing a positional hash.  [Feature #14183]
-
-    h = {}; def foo(*a) a end; foo(**h) # []
-    h = {}; def foo(a) a end; foo(**h)  # {} and warning
-    h = {}; def foo(*a) a end; foo(h)   # [{}]
-    h = {}; def foo(a) a end; foo(h)    # {}
-
-* Proc.new and Kernel#proc with no block in a method called with a block is
-  warned now.
-
-* Kernel#lambda with no block in a method called with a block errs.
-
-* Non-Symbol keys in a keyword arguments hash were prohibited in 2.6.0,
-  but are now allowed again.  [Bug #15658]
-
-* Numbered parameter as the default block parameter is introduced as an
-  experimental feature.  [Feature #4475]
-
-* A beginless range is experimentally introduced.  It might not be as useful
-  as an endless range, but would be good for DSL purpose.  [Feature #14799]
-
-     ary[..3]  # identical to ary[0..3]
-     where(sales: ..100)
-
-* Setting <code>$;</code> to non-nil value is warned now.  Use of it in
-  String#split is warned too.
-
-* Setting <code>$,</code> to non-nil value is warned now.  Use of it in
-  Array#join is warned too.
-
-* Quoted here-document identifier must end within the same line.
-
-     <<"EOS
-     " # This has been warned since 2.4
-     EOS
-
-
-* The flip-flop syntax deprecation is reverted. [Feature #5400]
-
-* Comment lines can be placed between fluent dot now.
-
-    foo
-      # .bar
-      .baz # => foo.baz
-
-* Calling a private method with a literal <code>self</code> as the receiver
-  is now allowed. [Feature #11297] [Feature #16123]
-
-=== Core classes updates (outstanding ones only)
-
-Complex::
-
-  New method::
-
-    * Added Complex#<=>. So 0 <=> 0i will not raise NoMethodError. [Bug #15857]
-
-Dir::
-
-  Modified method::
-
-    * Dir#glob and Dir#[] no longer allow NUL-separated glob pattern.
-      Use Array instead.  [Feature #14643]
-
-Encoding::
-
-  * Added new encoding CESU-8 [Feature #15931]
-
-Enumerable::
-
-  New methods::
-
-    * Added Enumerable#filter_map.  [Feature #15323]
-
-    * Added Enumerable#tally.  [Feature #11076]
-
-Enumerator::
-
-  New method::
-
-    * Added Enumerator::Lazy#eager that generates a non-lazy enumerator
-      from a lazy enumerator.  [Feature #15901]
-
-    * Added Enumerator::Yielder#to_proc so that a Yielder object
-      can be directly passed to another method as a block
-      argument.  [Feature #15618]
-
-Fiber::
-
-  New method::
-
-    * Added Fiber#raise that behaves like Fiber#resume but raises an
-      exception on the resumed fiber.  [Feature #10344]
-
-FrozenError::
-
-  New method::
-
-    * Added FrozenError#receiver to return the frozen object that
-      modification was attempted on.  To set this object when raising
-      FrozenError in Ruby code, pass it as the second argument to
-      FrozenError.new.
-
-GC::
-
-  New method::
-
-    * Added GC.compact method for compacting the heap.
-      This function compacts live objects in the heap so that fewer pages may
-      be used, and the heap may be more CoW friendly. [Feature #15626]
-
-      Details on the algorithm and caveats can be found here:
-      https://bugs.ruby-lang.org/issues/15626
-
-IO::
-
-  New method::
-
-    * Added IO#set_encoding_by_bom to check the BOM and set the external
-      encoding.  [Bug #15210]
-
-Integer::
-
-  Modified method::
-
-    * Integer#[] now supports range operation.  [Feature #8842]
-
-         0b01001101[2, 4]  #=> 0b0011
-         0b01001100[2..5]  #=> 0b0011
-         0b01001100[2...6] #=> 0b0011
-             ^^^^
-
-NilClass / TrueClass / FalseClass::
-
-  Modified method::
-
-    * NilClass#to_s, TrueClass#to_s and FalseClass#to_s now always returns a
-      frozen String. The returned String is always the same for each of these
-      values. This change is experimental. [Feature #16150]
-
-Module::
-
-  New method::
-
-    * Added Module#const_source_location to retrieve the location where a
-      constant is defined.  [Feature #10771]
-
-  Modified method::
-
-    * Module#autoload? now takes an +inherit+ optional argument, like as
-      Module#const_defined?.  [Feature #15777]
-
-    * Module#name now always return a frozen String. The returned String is
-      always the same for a given Module. This change is
-      experimental. [Feature #16150]
-
-ObjectSpace::WeakMap::
-
-  Modified method::
-
-    * ObjectSpace::WeakMap#[]= now accepts special objects as either key or
-      values.  [Feature #16035]
-
-Regexp / String::
-
-    * Update Unicode version and Emoji version from 11.0.0 to
-      12.0.0.  [Feature #15321]
-
-    * Update Unicode version to 12.1.0, adding support for
-      U+32FF SQUARE ERA NAME REIWA.  [Feature #15195]
-
-RubyVM::
-
-  Removed method::
-
-    * +RubyVM.resolve_feature_path+ moved to
-      <code>$LOAD_PATH.resolve_feature_path</code>.  [Feature #15903] [Feature #15230]
-
-Symbol::
-
-  Modified method::
-
-    * Symbol#to_s now always returns a frozen String. The returned String
-      is always the same for a given Symbol.  This change is
-      experimental.  [Feature #16150]
-
-Time::
-
-  New methods::
-
-    * Added Time#ceil method.  [Feature #15772]
-
-    * Added Time#floor method.  [Feature #15653]
-
-  Modified method::
-
-    * Time#inspect is separated from Time#to_s and it shows its sub
-      second.  [Feature #15958]
-
-UnboundMethod::
-
-  New methods::
-
-    * Added UnboundMethod#bind_call method.  [Feature #15955]
-
-      <code>umethod.bind_call(obj, ...)</code> is semantically equivalent
-      to <code>umethod.bind(obj).call(...)</code>.  This idiom is used in
-      some libraries to call a method that is overridden.  The added
-      method does the same without allocation of intermediate Method
-      object.
-
-          class Foo
-            def add_1(x)
-              x + 1
-            end
-          end
-          class Bar < Foo
-            def add_1(x) # override
-              x + 2
-            end
-          end
-
-          obj = Bar.new
-          p obj.add_1(1) #=> 3
-          p Foo.instance_method(:add_1).bind(obj).call(1) #=> 2
-          p Foo.instance_method(:add_1).bind_call(obj, 1) #=> 2
-
-
-$LOAD_PATH::
-
-  New method::
-
-    * Added <code>$LOAD_PATH.resolve_feature_path</code>.  [Feature #15903] [Feature #15230]
-
-=== Stdlib updates (outstanding ones only)
-
-Bundler::
-
-  * Upgrade to Bundler 2.1.0.pre.1
-    Bundled from https://github.com/bundler/bundler/commit/a53709556b95a914e874b22ed2116a46b0528852
-
-CGI::
-
-  * CGI.escapeHTML becomes 2~5x faster when there's at least one escaped character.
-
-CSV::
-
-  * Upgrade to 3.0.9.
-    See https://github.com/ruby/csv/blob/master/NEWS.md.
-
-Date::
-
-  * Date.jisx0301, Date#jisx0301, and Date.parse support the new Japanese
-    era.  [Feature #15742]
-
-Delegator::
-
-  * Object#DelegateClass accepts a block and module_evals it in the context
-    of the returned class, similar to Class.new and Struct.new.
-
-ERB::
-
-  * Prohibit marshaling ERB instance.
-
-IRB::
-
-  * Introduce syntax highlight inspired by pry.gem to Binding#irb source lines,
-    REPL input, and inspect output of some core-class objects.
-
-  * Introduce multiline mode by Reline.
-
-  * Show documents when completion.
-
-  * Enable auto indent and save/load history by default.
-
-Net::FTP::
-
-  * Add features and options.  [Feature #15964]
-
-Net::IMAP::
-
-  * Add Server Name Indication (SNI) support.  [Feature #15594]
-
-open-uri::
-
-  * Warn open-uri's "open" method at Kernel.
-    Use URI.open instead.  [Misc #15893]
-
-  * The default charset of text/* media type is UTF-8 instead of
-    ISO-8859-1.  [Bug #15933]
-
-Pathname::
-
-  * Delegates 3 arguments from Pathname.glob to Dir.glob to
-    accept base: keyword.
-
-Racc::
-
-  * Merge 1.4.15 from upstream repository and added cli of racc.
-
-Reline::
-
-  * New stdlib that is compatible with readline stdlib by pure Ruby and also
-    has a multiline mode.
-
-RSS::
-
-  * Upgrade to RSS 0.2.8.
-    See https://github.com/ruby/rss/blob/master/NEWS.md.
-
-RubyGems::
-
-  * Upgrade to RubyGems 3.1.0.pre1
-    Bundled from https://github.com/rubygems/rubygems/commit/97b264f0fa248c864b6ee9a23d3ff1cdd217dddb
-
-=== Compatibility issues (excluding feature bug fixes)
-
-* Removed unmaintained libraries.
-  * CMath
-  * Scanf
-  * Shell
-  * Synchronizer
-  * ThreadsWait
-
-=== Stdlib compatibility issues (excluding feature bug fixes)
-
-profile.rb, Profiler__::
-
-  * Removed from standard library. No one maintains it from Ruby 2.0.0.
-
-=== C API updates
-
-* C API declarations with +ANYARGS+ are changed not to use +ANYARGS+
-  https://github.com/ruby/ruby/pull/2404
-
-=== Implementation improvements
-
-Fiber::
-
-  * Allow selecting different coroutine implementation by using
-    `--with-coroutine=`, e.g.
-
-         ./confgure --with-coroutine=ucontext
-         ./confgure --with-coroutine=copy
-
-  * Replace previous stack cache with fiber pool cache. The fiber pool
-    allocates many stacks in a single memory region. Stack allocation
-    becomes O(log N) and fiber creation is amortized O(1). Around 10x
-    performance improvement was measured in micro-benchmarks.
-
-Thread::
-
-  * VM stack memory allocation is now combined with native thread stack,
-    improving thread allocation performance and reducing allocation related
-    failures. ~10x performance improvement was measured in micro-benchmarks.
-
-JIT::
-
-  * JIT-ed code is recompiled to less-optimized code when an optimization assumption is invalidated.
-
-  * Method inlining is performed when a method is considered as pure.
-    This optimization is still experimental and many methods are NOT considered as pure yet.
-
-  * Default value of +--jit-max-cache+ is changed from 1,000 to 100
-
-  * Default value of +--jit-min-calls+ is changed from 5 to 10,000
-
-=== Miscellaneous changes
-
-* Support for IA64 architecture has been removed. Hardware for testing was
-  difficult to find, native fiber code is difficult to implement, and it added
-  non-trivial complexity to the interpreter. [Feature #15894]
-
-* Require compilers to support C99 [Misc #15347]
-
-  * Details of our dialect: https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/C99
-
-* Ruby's upstream repository is changed from Subversion to Git.
-
-  * https://git.ruby-lang.org/ruby.git
-
-  * RUBY_REVISION class is changed from Integer to String.
-
-  * RUBY_DESCRIPTION includes Git revision instead of Subversion's one.
diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000000..9ff290ad75
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,269 @@
+# NEWS for Ruby 4.1.0
+
+This document is a list of user-visible feature changes
+since the **4.0.0** release, except for bug fixes.
+
+Note that each entry is kept to a minimum, see links for details.
+
+## Language changes
+
+* `Module#clone` and `Module#dup` no longer rewrite the lexical scope of
+  copied methods. Constants and class variables resolve through the
+  original class, consistent with inheritance and mixins.
+  [[Feature #21981]]
+
+## Core classes updates
+
+Note: We're only listing outstanding class updates.
+
+* Array
+
+    * `Array#pack` accepts a new format `R` and `r` for unpacking unsigned
+      and signed LEB128 encoded integers. [[Feature #21785]]
+    * `Array#pack` accepts a new format `^` that returns the current offset.
+      Useful when combined with variable width formats like LEB128. [[Feature #21796]]
+
+* ENV
+
+    * `ENV.fetch_values` is added. It returns an array of values for the
+      given names, raising `KeyError` for missing names unless a block is
+      given. [[Feature #21781]]
+
+* Kernel
+
+    * `Kernel#autoload_relative` and `Module#autoload_relative` are added.
+      These methods work like `autoload`, but resolve the file path relative
+      to the file where the method is called, similar to `require_relative`.
+      This makes it easier to autoload constants from files in the same
+      directory without hardcoding absolute paths or manipulating `$LOAD_PATH`.
+      [[Feature #15330]]
+
+* MatchData
+
+    * `MatchData#integer_at` is added.  It converts the matched substring to
+      integer and return the result.  [[Feature #21932]]
+
+* Regexp
+
+    * All instances of `Regexp` are now frozen, not just literals.
+      Subclasses of `Regexp` are not frozen for compatibility.
+      [[Feature #8948]]
+
+* Set
+
+    * A deprecated behavior, `Set#to_set`, `Range#to_set`, and
+      `Enumerable#to_set` accepting arguments, was removed.  [[Feature #21390]]
+
+## Stdlib updates
+
+### The following bundled gems are added.
+
+
+We only list stdlib changes that are notable feature changes.
+
+Other changes are listed in the following sections. We also listed release
+history from the previous bundled version that is Ruby 3.4.0 if it has GitHub
+releases.
+
+### The following bundled gems are promoted from default gems.
+
+* tsort 0.2.0
+* win32-registry 0.1.2
+
+### The following default gem is added.
+
+### The following default gems are updated.
+
+* RubyGems 4.1.0.dev
+  * 4.0.3 to [v4.0.4][RubyGems-v4.0.4], [v4.0.5][RubyGems-v4.0.5], [v4.0.6][RubyGems-v4.0.6], [v4.0.7][RubyGems-v4.0.7], [v4.0.8][RubyGems-v4.0.8], [v4.0.9][RubyGems-v4.0.9], [v4.0.10][RubyGems-v4.0.10], [v4.0.11][RubyGems-v4.0.11], [v4.0.12][RubyGems-v4.0.12], [v4.0.13][RubyGems-v4.0.13]
+* bundler 4.1.0.dev
+  * 4.0.3 to [v4.0.4][bundler-v4.0.4], [v4.0.5][bundler-v4.0.5], [v4.0.6][bundler-v4.0.6], [v4.0.7][bundler-v4.0.7], [v4.0.8][bundler-v4.0.8], [v4.0.9][bundler-v4.0.9], [v4.0.10][bundler-v4.0.10], [v4.0.11][bundler-v4.0.11], [v4.0.12][bundler-v4.0.12], [v4.0.13][bundler-v4.0.13]
+* erb 6.0.4
+  * 6.0.1 to [v6.0.1.1][erb-v6.0.1.1], [v6.0.2][erb-v6.0.2], [v6.0.3][erb-v6.0.3], [v6.0.4][erb-v6.0.4]
+* ipaddr 1.2.9
+  * 1.2.8 to [v1.2.9][ipaddr-v1.2.9]
+* json 2.19.8
+  * 2.18.0 to [v2.18.1][json-v2.18.1], [v2.19.0][json-v2.19.0], [v2.19.1][json-v2.19.1], [v2.19.2][json-v2.19.2], [v2.19.3][json-v2.19.3], [v2.19.4][json-v2.19.4], [v2.19.5][json-v2.19.5], [v2.19.6][json-v2.19.6], [v2.19.7][json-v2.19.7]
+* openssl 4.0.2
+  * 4.0.0 to [v4.0.1][openssl-v4.0.1], [v4.0.2][openssl-v4.0.2]
+* prism 1.9.0
+  * 1.7.0 to [v1.8.0][prism-v1.8.0], [v1.8.1][prism-v1.8.1], [v1.9.0][prism-v1.9.0]
+* psych 5.4.0
+* resolv 0.7.1
+  * 0.7.0 to [v0.7.1][resolv-v0.7.1]
+* stringio 3.2.1.dev
+* strscan 3.1.9.dev
+  * 3.1.6 to [v3.1.7][strscan-v3.1.7], [v3.1.8][strscan-v3.1.8]
+* syntax_suggest 3.0.0
+* timeout 0.6.1
+  * 0.6.0 to [v0.6.1][timeout-v0.6.1]
+* zlib 3.2.3
+  * 3.2.2 to [v3.2.3][zlib-v3.2.3]
+
+### The following bundled gems are updated.
+
+* minitest 6.0.6
+* rake 13.4.2
+  * 13.3.1 to [v13.4.0][rake-v13.4.0], [v13.4.1][rake-v13.4.1], [v13.4.2][rake-v13.4.2]
+* test-unit 3.7.8
+  * 3.7.5 to [3.7.6][test-unit-3.7.6], [3.7.7][test-unit-3.7.7], [3.7.8][test-unit-3.7.8]
+* net-imap 0.6.4
+  * 0.6.2 to [v0.6.3][net-imap-v0.6.3], [v0.6.4][net-imap-v0.6.4]
+* rbs 4.0.2
+  * 3.10.0 to [v3.10.1][rbs-v3.10.1], [v3.10.2][rbs-v3.10.2], [v3.10.3][rbs-v3.10.3], [v3.10.4][rbs-v3.10.4], [v4.0.0.dev.5][rbs-v4.0.0.dev.5], [v4.0.0][rbs-v4.0.0], [v4.0.2][rbs-v4.0.2]
+* typeprof 0.32.0
+* mutex_m 0.3.0
+* bigdecimal 4.1.2
+  * 4.0.1 to [v4.1.0][bigdecimal-v4.1.0], [v4.1.1][bigdecimal-v4.1.1], [v4.1.2][bigdecimal-v4.1.2]
+* resolv-replace 0.2.0
+  * 0.1.1 to [v0.2.0][resolv-replace-v0.2.0]
+* syslog 0.4.0
+  * 0.3.0 to [v0.4.0][syslog-v0.4.0]
+* repl_type_completor 0.1.15
+  * 0.1.12 to [v0.1.13][repl_type_completor-v0.1.13], [v0.1.14][repl_type_completor-v0.1.14], [v0.1.15][repl_type_completor-v0.1.15]
+* pstore 0.2.1
+  * 0.2.0 to [v0.2.1][pstore-v0.2.1]
+* rdoc 7.2.0
+  * 7.0.3 to [v7.0.4][rdoc-v7.0.4], [v7.1.0][rdoc-v7.1.0], [v7.2.0][rdoc-v7.2.0]
+* win32ole 1.9.3
+  * 1.9.2 to [v1.9.3][win32ole-v1.9.3]
+* irb 1.18.0
+  * 1.16.0 to [v1.17.0][irb-v1.17.0], [v1.18.0][irb-v1.18.0]
+
+### RubyGems and Bundler
+
+Ruby 4.0 bundled RubyGems and Bundler version 4. see the following links for details.
+
+## Supported platforms
+
+## Compatibility issues
+
+## Stdlib compatibility issues
+
+## C API updates
+
+### Embedded TypedData
+
+* The `RUBY_TYPED_EMBEDDABLE` flag is now public and documented and can be used by C extensions.
+  It allows allocating C structs directly into Ruby object slots, which reduces pointer chasing,
+  and in some case memory usage.
+  See the C extension documentation for details. [[Feature #21853]]
+
+* Added new C23 inspired allocator functions, that takes the previous memory size.
+  This allow the Ruby GC to better keep track of memory usage, improving its heuristics.
+  It also improves the performance of system allocators that support C23 `free_sized`.
+
+  However, it is important to note that passing an incorrect size to these function is undefined
+  behavior and may result in crashes or memory leaks.
+
+  - `ruby_xfree_sized(void *ptr, size_t size)`
+  - `ruby_xrealloc_sized(void *ptr, size_t newsiz, size_t oldsiz)`
+  - `ruby_xrealloc2_sized(void *ptr, size_t newelems, size_t newsiz, size_t oldelems)`
+
+  [[Feature #21861]]
+
+### Removed APIs
+
+The following APIs, which have been deprecated for many years, are removed.
+[[Feature #21768]]
+
+* old postponed job functions,
+* untyped data object type/functions,
+* old APIs to allocate a data object,
+* taintedness/trustedness enums/macros,
+* `rb_gc_force_recycle` function,
+* `rb_iterate` function,
+* and some functions and constants for internal use.
+
+## Implementation improvements
+
+### Ractor
+
+A lot of work has gone into making Ractors more stable, performant, and usable. These improvements bring Ractor implementation closer to leaving experimental status.
+
+## JIT
+
+[Feature #8948]: https://bugs.ruby-lang.org/issues/8948
+[Feature #15330]: https://bugs.ruby-lang.org/issues/15330
+[Feature #21390]: https://bugs.ruby-lang.org/issues/21390
+[Feature #21768]: https://bugs.ruby-lang.org/issues/21768
+[Feature #21785]: https://bugs.ruby-lang.org/issues/21785
+[Feature #21796]: https://bugs.ruby-lang.org/issues/21796
+[Feature #21853]: https://bugs.ruby-lang.org/issues/21853
+[Feature #21861]: https://bugs.ruby-lang.org/issues/21861
+[Feature #21932]: https://bugs.ruby-lang.org/issues/21932
+[Feature #21981]: https://bugs.ruby-lang.org/issues/21981
+[RubyGems-v4.0.4]: https://github.com/rubygems/rubygems/releases/tag/v4.0.4
+[RubyGems-v4.0.5]: https://github.com/rubygems/rubygems/releases/tag/v4.0.5
+[RubyGems-v4.0.6]: https://github.com/rubygems/rubygems/releases/tag/v4.0.6
+[RubyGems-v4.0.7]: https://github.com/rubygems/rubygems/releases/tag/v4.0.7
+[RubyGems-v4.0.8]: https://github.com/rubygems/rubygems/releases/tag/v4.0.8
+[RubyGems-v4.0.9]: https://github.com/rubygems/rubygems/releases/tag/v4.0.9
+[RubyGems-v4.0.10]: https://github.com/rubygems/rubygems/releases/tag/v4.0.10
+[RubyGems-v4.0.11]: https://github.com/rubygems/rubygems/releases/tag/v4.0.11
+[RubyGems-v4.0.12]: https://github.com/rubygems/rubygems/releases/tag/v4.0.12
+[RubyGems-v4.0.13]: https://github.com/rubygems/rubygems/releases/tag/v4.0.13
+[bundler-v4.0.4]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.4
+[bundler-v4.0.5]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.5
+[bundler-v4.0.6]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.6
+[bundler-v4.0.7]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.7
+[bundler-v4.0.8]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.8
+[bundler-v4.0.9]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.9
+[bundler-v4.0.10]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.10
+[bundler-v4.0.11]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.11
+[bundler-v4.0.12]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.12
+[bundler-v4.0.13]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.13
+[erb-v6.0.1.1]: https://github.com/ruby/erb/releases/tag/v6.0.1.1
+[erb-v6.0.2]: https://github.com/ruby/erb/releases/tag/v6.0.2
+[erb-v6.0.3]: https://github.com/ruby/erb/releases/tag/v6.0.3
+[erb-v6.0.4]: https://github.com/ruby/erb/releases/tag/v6.0.4
+[ipaddr-v1.2.9]: https://github.com/ruby/ipaddr/releases/tag/v1.2.9
+[json-v2.18.1]: https://github.com/ruby/json/releases/tag/v2.18.1
+[json-v2.19.0]: https://github.com/ruby/json/releases/tag/v2.19.0
+[json-v2.19.1]: https://github.com/ruby/json/releases/tag/v2.19.1
+[json-v2.19.2]: https://github.com/ruby/json/releases/tag/v2.19.2
+[json-v2.19.3]: https://github.com/ruby/json/releases/tag/v2.19.3
+[json-v2.19.4]: https://github.com/ruby/json/releases/tag/v2.19.4
+[json-v2.19.5]: https://github.com/ruby/json/releases/tag/v2.19.5
+[json-v2.19.6]: https://github.com/ruby/json/releases/tag/v2.19.6
+[json-v2.19.7]: https://github.com/ruby/json/releases/tag/v2.19.7
+[openssl-v4.0.1]: https://github.com/ruby/openssl/releases/tag/v4.0.1
+[openssl-v4.0.2]: https://github.com/ruby/openssl/releases/tag/v4.0.2
+[prism-v1.8.0]: https://github.com/ruby/prism/releases/tag/v1.8.0
+[prism-v1.8.1]: https://github.com/ruby/prism/releases/tag/v1.8.1
+[prism-v1.9.0]: https://github.com/ruby/prism/releases/tag/v1.9.0
+[resolv-v0.7.1]: https://github.com/ruby/resolv/releases/tag/v0.7.1
+[strscan-v3.1.7]: https://github.com/ruby/strscan/releases/tag/v3.1.7
+[strscan-v3.1.8]: https://github.com/ruby/strscan/releases/tag/v3.1.8
+[timeout-v0.6.1]: https://github.com/ruby/timeout/releases/tag/v0.6.1
+[zlib-v3.2.3]: https://github.com/ruby/zlib/releases/tag/v3.2.3
+[rake-v13.4.0]: https://github.com/ruby/rake/releases/tag/v13.4.0
+[rake-v13.4.1]: https://github.com/ruby/rake/releases/tag/v13.4.1
+[rake-v13.4.2]: https://github.com/ruby/rake/releases/tag/v13.4.2
+[test-unit-3.7.6]: https://github.com/test-unit/test-unit/releases/tag/3.7.6
+[test-unit-3.7.7]: https://github.com/test-unit/test-unit/releases/tag/3.7.7
+[test-unit-3.7.8]: https://github.com/test-unit/test-unit/releases/tag/3.7.8
+[net-imap-v0.6.3]: https://github.com/ruby/net-imap/releases/tag/v0.6.3
+[net-imap-v0.6.4]: https://github.com/ruby/net-imap/releases/tag/v0.6.4
+[rbs-v3.10.1]: https://github.com/ruby/rbs/releases/tag/v3.10.1
+[rbs-v3.10.2]: https://github.com/ruby/rbs/releases/tag/v3.10.2
+[rbs-v3.10.3]: https://github.com/ruby/rbs/releases/tag/v3.10.3
+[rbs-v3.10.4]: https://github.com/ruby/rbs/releases/tag/v3.10.4
+[rbs-v4.0.0.dev.5]: https://github.com/ruby/rbs/releases/tag/v4.0.0.dev.5
+[rbs-v4.0.0]: https://github.com/ruby/rbs/releases/tag/v4.0.0
+[rbs-v4.0.2]: https://github.com/ruby/rbs/releases/tag/v4.0.2
+[bigdecimal-v4.1.0]: https://github.com/ruby/bigdecimal/releases/tag/v4.1.0
+[bigdecimal-v4.1.1]: https://github.com/ruby/bigdecimal/releases/tag/v4.1.1
+[bigdecimal-v4.1.2]: https://github.com/ruby/bigdecimal/releases/tag/v4.1.2
+[resolv-replace-v0.2.0]: https://github.com/ruby/resolv-replace/releases/tag/v0.2.0
+[syslog-v0.4.0]: https://github.com/ruby/syslog/releases/tag/v0.4.0
+[repl_type_completor-v0.1.13]: https://github.com/ruby/repl_type_completor/releases/tag/v0.1.13
+[repl_type_completor-v0.1.14]: https://github.com/ruby/repl_type_completor/releases/tag/v0.1.14
+[repl_type_completor-v0.1.15]: https://github.com/ruby/repl_type_completor/releases/tag/v0.1.15
+[pstore-v0.2.1]: https://github.com/ruby/pstore/releases/tag/v0.2.1
+[rdoc-v7.0.4]: https://github.com/ruby/rdoc/releases/tag/v7.0.4
+[rdoc-v7.1.0]: https://github.com/ruby/rdoc/releases/tag/v7.1.0
+[rdoc-v7.2.0]: https://github.com/ruby/rdoc/releases/tag/v7.2.0
+[win32ole-v1.9.3]: https://github.com/ruby/win32ole/releases/tag/v1.9.3
+[irb-v1.17.0]: https://github.com/ruby/irb/releases/tag/v1.17.0
+[irb-v1.18.0]: https://github.com/ruby/irb/releases/tag/v1.18.0
diff --git a/README.EXT b/README.EXT
deleted file mode 100644
index 48b8d964c4..0000000000
--- a/README.EXT
+++ /dev/null
@@ -1 +0,0 @@
-Moved to doc/extension.rdoc
diff --git a/README.EXT.ja b/README.EXT.ja
deleted file mode 100644
index f884ecbb0e..0000000000
--- a/README.EXT.ja
+++ /dev/null
@@ -1 +0,0 @@
-doc/extension.ja.rdocに移動しました
diff --git a/README.ja.md b/README.ja.md
index 984a5658ea..9bbc3a83a5 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -1,11 +1,10 @@
-[![Build Status](https://travis-ci.org/ruby/ruby.svg?branch=master)](https://travis-ci.org/ruby/ruby)
-[![wercker status](https://app.wercker.com/status/e5e7e1704f62b76525022aa424aef6ef/s/master "wercker status")](https://app.wercker.com/project/byKey/e5e7e1704f62b76525022aa424aef6ef)
-[![Build status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
-[![Build Status](https://dev.azure.com/rubylang/ruby/_apis/build/status/ruby.ruby?branchName=master)](https://dev.azure.com/rubylang/ruby/_build/latest?definitionId=3&branchName=master)
-![](https://github.com/ruby/ruby/workflows/macos/badge.svg)
-![](https://github.com/ruby/ruby/workflows/ubuntu/badge.svg)
-![](https://github.com/ruby/ruby/workflows/windows/badge.svg)
+[![Actions Status: MinGW](https://github.com/ruby/ruby/workflows/MinGW/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MinGW")
+[![Actions Status: Ubuntu](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Ubuntu")
+[![Actions Status: Windows](https://github.com/ruby/ruby/workflows/Windows/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Windows")
+[![AppVeyor status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
+[![Travis Status](https://app.travis-ci.com/ruby/ruby.svg?branch=master)](https://app.travis-ci.com/ruby/ruby)
 
+[English](rdoc-ref:README.md)
 
 # Rubyとは
 
@@ -27,7 +26,7 @@ Rubyはテキスト処理関係の能力などに優れ，Perlと同じくらい
 *   ダイナミックローディング (アーキテクチャによる)
 *   移植性が高い．多くのUnix-like/POSIX互換プラットフォーム上で動くだけでなく，Windows， macOS，
     Haikuなどの上でも動く cf.
-    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#platform-maintainers
+    https://docs.ruby-lang.org/en/master/maintainers_md.html#label-Platform+Maintainers
 
 
 ## 入手法
@@ -42,26 +41,19 @@ https://www.ruby-lang.org/ja/downloads/
 
 ミラーをGitHubに公開しています． 以下のコマンドでリポジトリを取得できます．
 
-    $ git clone https://github.com/ruby/ruby.git
+```console
+$ git clone https://github.com/ruby/ruby.git
+```
 
 他のブランチの一覧は次のコマンドで見られます．
 
-    $ git ls-remote https://github.com/ruby/ruby.git
+```console
+$ git ls-remote https://github.com/ruby/ruby.git
+```
 
 Rubyリポジトリの本来のmasterは https://git.ruby-lang.org/ruby.git にあります．
 コミッタはこちらを使います．
 
-### Subversion
-
-古いRubyのバージョンのソースコードは次のコマンドで取得できます．
-
-    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
-
-他に開発中のブランチの一覧は次のコマンドで見られます．
-
-    $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
-
-
 ## ホームページ
 
 RubyのホームページのURLは
@@ -72,38 +64,33 @@ https://www.ruby-lang.org/
 
 ## メーリングリスト
 
-Rubyのメーリングリストがあります．参加希望の方は
+Rubyのメーリングリストがあります．参加希望の方は [ruby-list-request@ml.ruby-lang.org] まで件名に
 
-mailto:ruby-list-request@ruby-lang.org
-
-まで本文に
-
-    subscribe
+    join
 
 と書いて送って下さい．
 
-Ruby開発者向けメーリングリストもあります．こちらではrubyのバグ，将来の仕様拡張など実装上の問題について議論されています． 参加希望の方は
-
-mailto:ruby-dev-request@ruby-lang.org
-
-までruby-listと同様の方法でメールしてください．
+Ruby開発者向けメーリングリストもあります．こちらではrubyのバグ，将来の仕様拡張など実装上の問題について議論されています．
+参加希望の方は [ruby-dev-request@ml.ruby-lang.org] までruby-listと同様の方法でメールしてください．
 
 Ruby拡張モジュールについて話し合うruby-extメーリングリストと数学関係の話題について話し合うruby-mathメーリングリストと
 英語でrubyについて話し合うruby-talkメーリングリストもあります．参加方法はどれも同じです．
 
+[ruby-list-request@ml.ruby-lang.org]: mailto:ruby-list-request@ml.ruby-lang.org?subject=join
+[ruby-dev-request@ml.ruby-lang.org]: mailto:ruby-dev-request@ml.ruby-lang.org?subject=join
+
 ## コンパイル・インストール
 
 以下の手順で行ってください．
 
-1.  もし `configure` ファイルが見つからない，もしくは `configure.ac` より古いようなら， `autoconf` を実行して
-    新しく `configure` を生成する
+1.  (Gitリポジトリから取得したソースをビルドする場合) `./autogen.sh` を実行して新しく `configure` を生成する
 
 2.  `configure` を実行して `Makefile` などを生成する
 
     環境によってはデフォルトのCコンパイラ用オプションが付きます． `configure` オプションで `optflags=..`
     `warnflags=..` 等で上書きできます．
 
-3.  (必要ならば)`defines.h` を編集する
+3.  (必要ならば)`include/ruby/defines.h` を編集する
 
     多分，必要無いと思います．
 
@@ -169,15 +156,18 @@ UNIXであれば `configure` がほとんどの差異を吸収してくれるは
 
 ## 配布条件
 
-[COPYING.ja](COPYING.ja) ファイルを参照してください．
+[COPYING.ja](https://docs.ruby-lang.org/en/master/COPYING_ja.html) ファイルを参照してください．
 
 ## フィードバック
 
-Rubyに関する質問は Ruby-Talk（英語）や Ruby-List（日本語） (https://www.ruby-lang.org/ja/community/mailing-lists) や，
-stackoverflow (https://ja.stackoverflow.com/) などのWebサイトに投稿してください．
+Rubyに関する質問は [Ruby-Talk]（英語）や [Ruby-List]（日本語）や，
+[stackoverflow] などのWebサイトに投稿してください．
 
 バグ報告は https://bugs.ruby-lang.org で受け付けています．
 
+[Ruby-Talk]: https://www.ruby-lang.org/en/community/mailing-lists
+[Ruby-List]: https://www.ruby-lang.org/ja/community/mailing-lists
+[stackoverflow]: https://ja.stackoverflow.com/
 
 ## 著者
 
diff --git a/README.md b/README.md
index c2e4eea6e7..02435b419e 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,11 @@
-[![Build Status](https://travis-ci.org/ruby/ruby.svg?branch=master)](https://travis-ci.org/ruby/ruby)
-[![wercker status](https://app.wercker.com/status/e5e7e1704f62b76525022aa424aef6ef/s/master "wercker status")](https://app.wercker.com/project/byKey/e5e7e1704f62b76525022aa424aef6ef)
-[![Build status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
-[![Build Status](https://dev.azure.com/rubylang/ruby/_apis/build/status/ruby.ruby?branchName=master)](https://dev.azure.com/rubylang/ruby/_build/latest?definitionId=3&branchName=master)
-![](https://github.com/ruby/ruby/workflows/macos/badge.svg)
-![](https://github.com/ruby/ruby/workflows/ubuntu/badge.svg)
-![](https://github.com/ruby/ruby/workflows/windows/badge.svg)
+[![Actions Status: MinGW](https://github.com/ruby/ruby/workflows/MinGW/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MinGW")
+[![Actions Status: Ubuntu](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Ubuntu")
+[![Actions Status: Windows](https://github.com/ruby/ruby/workflows/Windows/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Windows")
+[![Travis Status](https://app.travis-ci.com/ruby/ruby.svg?branch=master)](https://app.travis-ci.com/ruby/ruby)
 
-# What's Ruby
+[日本語](rdoc-ref:README.ja.md)
+
+# What is Ruby?
 
 Ruby is an interpreted object-oriented programming language often
 used for web development. It also offers many scripting features
@@ -15,18 +14,17 @@ It is simple, straightforward, and extensible.
 
 ## Features of Ruby
 
-*   Simple Syntax
-*   **Normal** Object-oriented Features (e.g. class, method calls)
-*   **Advanced** Object-oriented Features (e.g. mix-in, singleton-method)
-*   Operator Overloading
-*   Exception Handling
-*   Iterators and Closures
-*   Garbage Collection
-*   Dynamic Loading of Object Files (on some architectures)
-*   Highly Portable (works on many Unix-like/POSIX compatible platforms as
-    well as Windows, macOS, Haiku, etc.) cf.
-    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#platform-maintainers
-
+* Simple Syntax
+* **Normal** Object-oriented Features (e.g. class, method calls)
+* **Advanced** Object-oriented Features (e.g. mix-in, singleton-method)
+* Operator Overloading
+* Exception Handling
+* Iterators and Closures
+* Garbage Collection
+* Dynamic Loading of Object Files (on some architectures)
+* Highly Portable (works on many Unix-like/POSIX compatible platforms as
+  well as Windows, macOS, etc.) cf.
+    https://docs.ruby-lang.org/en/master/maintainers_md.html#label-Platform+Maintainers
 
 ## How to get Ruby
 
@@ -35,7 +33,10 @@ like rvm, see:
 
 https://www.ruby-lang.org/en/downloads/
 
-### Git
+You can download release packages and the snapshot of the repository. If you want to
+download whole versions of Ruby, please visit https://www.ruby-lang.org/en/downloads/releases/.
+
+### Download with Git
 
 The mirror of the Ruby source tree can be checked out with the following command:
 
@@ -49,125 +50,44 @@ to see the list of branches:
 You may also want to use https://git.ruby-lang.org/ruby.git (actual master of Ruby source)
 if you are a committer.
 
-### Subversion
-
-Stable branches for older Ruby versions can be checked out with the following command:
-
-    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
-
-Try the following command to see the list of branches:
-
-    $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
+## How to build
 
+See [Building Ruby](https://docs.ruby-lang.org/en/master/contributing/building_ruby_md.html)
 
 ## Ruby home page
 
 https://www.ruby-lang.org/
 
+## Documentation
+
+- [English](https://docs.ruby-lang.org/en/master/index.html)
+- [Japanese](https://docs.ruby-lang.org/ja/master/index.html)
+
 ## Mailing list
 
 There is a mailing list to discuss Ruby. To subscribe to this list, please
 send the following phrase:
 
-    subscribe
-
-in the mail body (not subject) to the address
-[ruby-talk-request@ruby-lang.org](mailto:ruby-talk-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe).
-
-## How to compile and install
-
-1.  If you want to use Microsoft Visual C++ to compile Ruby, read
-    [win32/README.win32](win32/README.win32) instead of this document.
-
-2.  If `./configure` does not exist or is older than `configure.ac`, run
-    `autoconf` to (re)generate configure.
-
-3.  Run `./configure`, which will generate `config.h` and `Makefile`.
-
-    Some C compiler flags may be added by default depending on your
-    environment. Specify `optflags=..` and `warnflags=..` as necessary to
-    override them.
-
-4.  Edit `defines.h` if you need. Usually this step will not be needed.
+    join
 
-5.  Remove comment mark(`#`) before the module names from `ext/Setup` (or add
-    module names if not present), if you want to link modules statically.
+in the mail subject (not body) to the address [ruby-talk-request@ml.ruby-lang.org].
 
-    If you don't want to compile non static extension modules (probably on
-    architectures which do not allow dynamic loading), remove comment mark
-    from the line "`#option nodynamic`" in `ext/Setup`.
-
-    Usually this step will not be needed.
-
-6.  Run `make`.
-
-    * On Mac, set RUBY\_CODESIGN environment variable with a signing identity.
-      It uses the identity to sign `ruby` binary. See also codesign(1).
-
-7.  Optionally, run '`make check`' to check whether the compiled Ruby
-    interpreter works well. If you see the message "`check succeeded`", your
-    Ruby works as it should (hopefully).
-
-8.  Optionally, run `make update-gems` and `make extract-gems`.
-
-    If you want to install bundled gems, run `make update-gems` and
-    `make extract-gems` before running `make install`.
-
-9.  Run '`make install`'.
-
-    This command will create the following directories and install files into
-    them.
-
-    *   `${DESTDIR}${prefix}/bin`
-    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib`
-    *   `${DESTDIR}${prefix}/lib/ruby`
-    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby`
-    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby`
-    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib/ruby/gems/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/share/man/man1`
-    *   `${DESTDIR}${prefix}/share/ri/${MAJOR}.${MINOR}.${TEENY}/system`
-
-
-    If Ruby's API version is '*x.y.z*', the `${MAJOR}` is '*x*', the
-    `${MINOR}` is '*y*', and the `${TEENY}` is '*z*'.
-
-    **NOTE**: teeny of the API version may be different from one of Ruby's
-    program version
-
-    You may have to be a super user to install Ruby.
-
-If you fail to compile Ruby, please send the detailed error report with the
-error log and machine/OS type, to help others.
-
-Some extension libraries may not get compiled because of lack of necessary
-external libraries and/or headers, then you will need to run '`make distclean-ext`'
-to remove old configuration after installing them in such case.
+[ruby-talk-request@ml.ruby-lang.org]: mailto:ruby-talk-request@ml.ruby-lang.org?subject=join
 
 ## Copying
 
-See the file [COPYING](COPYING).
+See the file [COPYING](rdoc-ref:COPYING).
 
 ## Feedback
 
-Questions about the Ruby language can be asked on the Ruby-Talk mailing list
-(https://www.ruby-lang.org/en/community/mailing-lists) or on websites like
-(https://stackoverflow.com).
-
-Bugs should be reported at https://bugs.ruby-lang.org. Read [HowToReport] for more information.
+Questions about the Ruby language can be asked on the [Ruby-Talk](https://www.ruby-lang.org/en/community/mailing-lists) mailing list
+or on websites like https://stackoverflow.com.
 
-[HowToReport]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToReport
+Bugs should be reported at https://bugs.ruby-lang.org. Read ["Reporting Issues"](https://docs.ruby-lang.org/en/master/contributing/reporting_issues_md.html) for more information.
 
 ## Contributing
 
-See the file [CONTRIBUTING.md](CONTRIBUTING.md)
+See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing/contributing_md.html), which includes setup and build instructions.
 
 ## The Author
 
diff --git a/aclocal.m4 b/aclocal.m4
index ed7d14ef63..e69de29bb2 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1,47 +0,0 @@
-# generated automatically by aclocal 1.16.1 -*- Autoconf -*-
-
-# Copyright (C) 1996-2018 Free Software Foundation, Inc.
-
-# This file is free software; the Free Software Foundation
-# gives unlimited permission to copy and/or distribute it,
-# with or without modifications, as long as this notice is preserved.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
-# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
-# PARTICULAR PURPOSE.
-
-m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
-m4_include([tool/m4/_colorize_result_prepare.m4])
-m4_include([tool/m4/ac_msg_result.m4])
-m4_include([tool/m4/colorize_result.m4])
-m4_include([tool/m4/ruby_append_option.m4])
-m4_include([tool/m4/ruby_append_options.m4])
-m4_include([tool/m4/ruby_check_builtin_func.m4])
-m4_include([tool/m4/ruby_check_builtin_setjmp.m4])
-m4_include([tool/m4/ruby_check_printf_prefix.m4])
-m4_include([tool/m4/ruby_check_setjmp.m4])
-m4_include([tool/m4/ruby_check_signedness.m4])
-m4_include([tool/m4/ruby_check_sizeof.m4])
-m4_include([tool/m4/ruby_check_sysconf.m4])
-m4_include([tool/m4/ruby_cppoutfile.m4])
-m4_include([tool/m4/ruby_decl_attribute.m4])
-m4_include([tool/m4/ruby_default_arch.m4])
-m4_include([tool/m4/ruby_define_if.m4])
-m4_include([tool/m4/ruby_defint.m4])
-m4_include([tool/m4/ruby_dtrace_available.m4])
-m4_include([tool/m4/ruby_dtrace_postprocess.m4])
-m4_include([tool/m4/ruby_func_attribute.m4])
-m4_include([tool/m4/ruby_mingw32.m4])
-m4_include([tool/m4/ruby_prepend_option.m4])
-m4_include([tool/m4/ruby_prog_gnu_ld.m4])
-m4_include([tool/m4/ruby_replace_funcs.m4])
-m4_include([tool/m4/ruby_replace_type.m4])
-m4_include([tool/m4/ruby_rm_recursive.m4])
-m4_include([tool/m4/ruby_setjmp_type.m4])
-m4_include([tool/m4/ruby_stack_grow_direction.m4])
-m4_include([tool/m4/ruby_try_cflags.m4])
-m4_include([tool/m4/ruby_try_ldflags.m4])
-m4_include([tool/m4/ruby_type_attribute.m4])
-m4_include([tool/m4/ruby_universal_arch.m4])
-m4_include([tool/m4/ruby_werror_flag.m4])
diff --git a/addr2line.c b/addr2line.c
index 635194b96b..19a6a425c1 100644
--- a/addr2line.c
+++ b/addr2line.c
@@ -8,12 +8,16 @@
 
 **********************************************************************/
 
-#if defined(__clang__)
+#if defined(__clang__) && defined(__has_warning)
+#if __has_warning("-Wgnu-empty-initializer")
 #pragma clang diagnostic ignored "-Wgnu-empty-initializer"
+#endif
+#if __has_warning("-Wgcc-compat")
 #pragma clang diagnostic ignored "-Wgcc-compat"
 #endif
+#endif
 
-#include "ruby/config.h"
+#include "ruby/internal/config.h"
 #include "ruby/defines.h"
 #include "ruby/missing.h"
 #include "addr2line.h"
@@ -25,11 +29,7 @@
 #include <libproc.h>
 #endif
 
-#ifdef HAVE_STDBOOL_H
-#include <stdbool.h>
-#else
-#include "missing/stdbool.h"
-#endif
+#include "ruby/internal/stdbool.h"
 
 #if defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H)
 
@@ -56,13 +56,26 @@
 #  ifdef _AIX
 #pragma alloca
 #  else
-#   ifndef alloca		/* predefined by HP cc +Olibcalls */
+#   ifndef alloca                /* predefined by HP cc +Olibcalls */
 void *alloca();
 #   endif
 #  endif /* AIX */
-# endif	/* HAVE_ALLOCA_H */
+# endif        /* HAVE_ALLOCA_H */
+# ifndef UNREACHABLE
+#  define UNREACHABLE __builtin_unreachable()
+# endif
+# ifndef UNREACHABLE_RETURN
+#  define UNREACHABLE_RETURN(_) __builtin_unreachable()
+# endif
 #endif /* __GNUC__ */
 
+#ifndef UNREACHABLE
+# define UNREACHABLE abort()
+#endif
+#ifndef UNREACHABLE_RETURN
+# define UNREACHABLE_RETURN(_) return (abort(), (_))
+#endif
+
 #ifdef HAVE_DLADDR
 # include <dlfcn.h>
 #endif
@@ -131,7 +144,7 @@ void *alloca();
 #define DW_LNE_define_file              0x03
 #define DW_LNE_set_discriminator        0x04  /* DWARF4 */
 
-PRINTF_ARGS(static int kprintf(const char *fmt, ...), 1, 2);
+#define kprintf(...) fprintf(errout, "" __VA_ARGS__)
 
 typedef struct line_info {
     const char *dirname;
@@ -163,11 +176,15 @@ typedef struct obj_info {
     struct dwarf_section debug_info;
     struct dwarf_section debug_line;
     struct dwarf_section debug_ranges;
+    struct dwarf_section debug_str_offsets;
+    struct dwarf_section debug_addr;
+    struct dwarf_section debug_rnglists;
     struct dwarf_section debug_str;
+    struct dwarf_section debug_line_str;
     struct obj_info *next;
 } obj_info_t;
 
-#define DWARF_SECTION_COUNT 5
+#define DWARF_SECTION_COUNT 9
 
 static struct dwarf_section *
 obj_dwarf_section_at(obj_info_t *obj, int n)
@@ -177,10 +194,14 @@ obj_dwarf_section_at(obj_info_t *obj, int n)
         &obj->debug_info,
         &obj->debug_line,
         &obj->debug_ranges,
-        &obj->debug_str
+        &obj->debug_str_offsets,
+        &obj->debug_addr,
+        &obj->debug_rnglists,
+        &obj->debug_str,
+        &obj->debug_line_str
     };
     if (n < 0 || DWARF_SECTION_COUNT <= n) {
-        abort();
+        UNREACHABLE_RETURN(0);
     }
     return ary[n];
 }
@@ -194,107 +215,125 @@ struct debug_section_definition {
 static char binary_filename[PATH_MAX + 1];
 
 static unsigned long
-uleb128(char **p)
+uleb128(const char **p)
 {
     unsigned long r = 0;
     int s = 0;
     for (;;) {
-	unsigned char b = *(unsigned char *)(*p)++;
-	if (b < 0x80) {
-	    r += (unsigned long)b << s;
-	    break;
-	}
-	r += (b & 0x7f) << s;
-	s += 7;
+        unsigned char b = (unsigned char)*(*p)++;
+        if (b < 0x80) {
+            r += (unsigned long)b << s;
+            break;
+        }
+        r += (b & 0x7f) << s;
+        s += 7;
     }
     return r;
 }
 
 static long
-sleb128(char **p)
+sleb128(const char **p)
 {
     long r = 0;
     int s = 0;
     for (;;) {
-	unsigned char b = *(unsigned char *)(*p)++;
-	if (b < 0x80) {
-	    if (b & 0x40) {
-		r -= (0x80 - b) << s;
-	    }
-	    else {
-		r += (b & 0x3f) << s;
-	    }
-	    break;
-	}
-	r += (b & 0x7f) << s;
-	s += 7;
+        unsigned char b = (unsigned char)*(*p)++;
+        if (b < 0x80) {
+            if (b & 0x40) {
+                r -= (0x80 - b) << s;
+            }
+            else {
+                r += (b & 0x3f) << s;
+            }
+            break;
+        }
+        r += (b & 0x7f) << s;
+        s += 7;
     }
     return r;
 }
 
 static const char *
-get_nth_dirname(unsigned long dir, char *p)
+get_nth_dirname(unsigned long dir, const char *p, FILE *errout)
 {
     if (!dir--) {
-	return "";
+        return "";
     }
     while (dir--) {
-	while (*p) p++;
-	p++;
-	if (!*p) {
-	    kprintf("Unexpected directory number %lu in %s\n",
-		    dir, binary_filename);
-	    return "";
-	}
+        while (*p) p++;
+        p++;
+        if (!*p) {
+            kprintf("Unexpected directory number %lu in %s\n",
+                    dir, binary_filename);
+            return "";
+        }
     }
     return p;
 }
 
+static const char *parse_ver5_debug_line_header(
+    const char *p, int idx, uint8_t format,
+    obj_info_t *obj, const char **out_path,
+    uint64_t *out_directory_index, FILE *errout);
+
 static void
-fill_filename(int file, char *include_directories, char *filenames, line_info_t *line, obj_info_t *obj)
+fill_filename(int file, uint8_t format, uint16_t version, const char *include_directories,
+              const char *filenames, line_info_t *line, obj_info_t *obj, FILE *errout)
 {
     int i;
-    char *p = filenames;
-    char *filename;
+    const char *p = filenames;
+    const char *filename;
     unsigned long dir;
-    for (i = 1; i <= file; i++) {
-	filename = p;
-	if (!*p) {
-	    /* Need to output binary file name? */
-	    kprintf("Unexpected file number %d in %s at %tx\n",
-		    file, binary_filename, filenames - obj->mapped);
-	    return;
-	}
-	while (*p) p++;
-	p++;
-	dir = uleb128(&p);
-	/* last modified. */
-	uleb128(&p);
-	/* size of the file. */
-	uleb128(&p);
-
-	if (i == file) {
-	    line->filename = filename;
-	    line->dirname = get_nth_dirname(dir, include_directories);
-	}
+    if (version >= 5) {
+        const char *path;
+        uint64_t directory_index = -1;
+        parse_ver5_debug_line_header(filenames, file, format, obj, &path, &directory_index, errout);
+        line->filename = path;
+        parse_ver5_debug_line_header(include_directories, (int)directory_index, format, obj, &path, NULL, errout);
+        line->dirname = path;
+    }
+    else {
+        for (i = 1; i <= file; i++) {
+            filename = p;
+            if (!*p) {
+#ifndef __APPLE__
+                /* Need to output binary file name? */
+                kprintf("Unexpected file number %d in %s at %tx\n",
+                        file, binary_filename, filenames - obj->mapped);
+#endif
+                return;
+            }
+            while (*p) p++;
+            p++;
+            dir = uleb128(&p);
+            /* last modified. */
+            uleb128(&p);
+            /* size of the file. */
+            uleb128(&p);
+
+            if (i == file) {
+                line->filename = filename;
+                line->dirname = get_nth_dirname(dir, include_directories, errout);
+            }
+        }
     }
 }
 
 static void
 fill_line(int num_traces, void **traces, uintptr_t addr, int file, int line,
-	  char *include_directories, char *filenames,
-	  obj_info_t *obj, line_info_t *lines, int offset)
+          uint8_t format, uint16_t version, const char *include_directories, const char *filenames,
+          obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
     int i;
     addr += obj->base_addr - obj->vmaddr;
     for (i = offset; i < num_traces; i++) {
-	uintptr_t a = (uintptr_t)traces[i];
-	/* We assume one line code doesn't result >100 bytes of native code.
+        uintptr_t a = (uintptr_t)traces[i];
+        /* We assume one line code doesn't result >100 bytes of native code.
        We may want more reliable way eventually... */
-	if (addr < a && a < addr + 100) {
-	    fill_filename(file, include_directories, filenames, &lines[i], obj);
-	    lines[i].line = line;
-	}
+        if (addr < a && a < addr + 100) {
+            fill_filename(file, format, version, include_directories, filenames, &lines[i], obj, errout);
+            lines[i].line = line;
+        }
     }
 }
 
@@ -317,7 +356,7 @@ struct LineNumberProgramHeader {
 };
 
 static int
-parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
+parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgramHeader *header, FILE *errout)
 {
     const char *p = *pp;
     header->unit_length = *(uint32_t *)p;
@@ -325,8 +364,8 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
 
     header->format = 4;
     if (header->unit_length == 0xffffffff) {
-	header->unit_length = *(uint64_t *)p;
-	p += sizeof(uint64_t);
+        header->unit_length = *(uint64_t *)p;
+        p += sizeof(uint64_t);
         header->format = 8;
     }
 
@@ -334,7 +373,13 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
 
     header->version = *(uint16_t *)p;
     p += sizeof(uint16_t);
-    if (header->version > 4) return -1;
+    if (header->version > 5) return -1;
+
+    if (header->version >= 5) {
+        /* address_size = *(uint8_t *)p++; */
+        /* segment_selector_size = *(uint8_t *)p++; */
+        p += 2;
+    }
 
     header->header_length = header->format == 4 ? *(uint32_t *)p : *(uint64_t *)p;
     p += header->format;
@@ -355,20 +400,27 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
     /* header->standard_opcode_lengths = (uint8_t *)p - 1; */
     p += header->opcode_base - 1;
 
-    header->include_directories = p;
+    if (header->version >= 5) {
+        header->include_directories = p;
+        p = parse_ver5_debug_line_header(p, -1, header->format, obj, NULL, NULL, errout);
+        header->filenames = p;
+    }
+    else {
+        header->include_directories = p;
 
-    /* temporary measure for compress-debug-sections */
-    if (p >= header->cu_end) return -1;
+        /* temporary measure for compress-debug-sections */
+        if (p >= header->cu_end) return -1;
 
-    /* skip include directories */
-    while (*p) {
-	p = memchr(p, '\0', header->cu_end - p);
-	if (!p) return -1;
-	p++;
-    }
-    p++;
+        /* skip include directories */
+        while (*p) {
+            p = memchr(p, '\0', header->cu_end - p);
+            if (!p) return -1;
+            p++;
+        }
+        p++;
 
-    header->filenames = p;
+        header->filenames = p;
+    }
 
     *pp = header->cu_start;
 
@@ -376,8 +428,8 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
 }
 
 static int
-parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
-		obj_info_t *obj, line_info_t *lines, int offset)
+parse_debug_line_cu(int num_traces, void **traces, const char **debug_line,
+                obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
     const char *p = (const char *)*debug_line;
     struct LineNumberProgramHeader header;
@@ -394,106 +446,109 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
     /* int epilogue_begin = 0; */
     /* unsigned int isa = 0; */
 
-    if (parse_debug_line_header(&p, &header))
+    if (parse_debug_line_header(obj, &p, &header, errout))
         return -1;
     is_stmt = header.default_is_stmt;
 
-#define FILL_LINE()						    \
-    do {							    \
-	fill_line(num_traces, traces, addr, file, line,		    \
-                  (char *)header.include_directories,               \
-                  (char *)header.filenames,                         \
-		  obj, lines, offset);				    \
-	/*basic_block = prologue_end = epilogue_begin = 0;*/	    \
+#define FILL_LINE()                                                 \
+    do {                                                            \
+        fill_line(num_traces, traces, addr, file, line,             \
+                  header.format,                                    \
+                  header.version,                                   \
+                  header.include_directories,                       \
+                  header.filenames,                                 \
+                  obj, lines, offset, errout);                      \
+        /*basic_block = prologue_end = epilogue_begin = 0;*/        \
     } while (0)
 
     while (p < header.cu_end) {
-	unsigned long a;
-	unsigned char op = *p++;
-	switch (op) {
-	case DW_LNS_copy:
-	    FILL_LINE();
-	    break;
-	case DW_LNS_advance_pc:
-	    a = uleb128((char **)&p);
-	    addr += a;
-	    break;
-	case DW_LNS_advance_line: {
-	    long a = sleb128((char **)&p);
-	    line += a;
-	    break;
-	}
-	case DW_LNS_set_file:
-	    file = (unsigned int)uleb128((char **)&p);
-	    break;
-	case DW_LNS_set_column:
-	    /*column = (unsigned int)*/(void)uleb128((char **)&p);
-	    break;
-	case DW_LNS_negate_stmt:
-	    is_stmt = !is_stmt;
-	    break;
-	case DW_LNS_set_basic_block:
-	    /*basic_block = 1; */
-	    break;
-	case DW_LNS_const_add_pc:
-	    a = ((255UL - header.opcode_base) / header.line_range) *
-		header.minimum_instruction_length;
-	    addr += a;
-	    break;
-	case DW_LNS_fixed_advance_pc:
-	    a = *(unsigned char *)p++;
-	    addr += a;
-	    break;
-	case DW_LNS_set_prologue_end:
-	    /* prologue_end = 1; */
-	    break;
-	case DW_LNS_set_epilogue_begin:
-	    /* epilogue_begin = 1; */
-	    break;
-	case DW_LNS_set_isa:
-	    /* isa = (unsigned int)*/(void)uleb128((char **)&p);
-	    break;
-	case 0:
-	    a = *(unsigned char *)p++;
-	    op = *p++;
-	    switch (op) {
-	    case DW_LNE_end_sequence:
-		/* end_sequence = 1; */
-		FILL_LINE();
-		addr = 0;
-		file = 1;
-		line = 1;
-		/* column = 0; */
-		is_stmt = header.default_is_stmt;
-		/* end_sequence = 0; */
-		/* isa = 0; */
-		break;
-	    case DW_LNE_set_address:
-		addr = *(unsigned long *)p;
-		p += sizeof(unsigned long);
-		break;
-	    case DW_LNE_define_file:
-		kprintf("Unsupported operation in %s\n",
-			binary_filename);
-		break;
-	    case DW_LNE_set_discriminator:
-		/* TODO:currently ignore */
-		uleb128((char **)&p);
-		break;
-	    default:
-		kprintf("Unknown extended opcode: %d in %s\n",
-			op, binary_filename);
-	    }
-	    break;
-	default: {
+        unsigned long a;
+        unsigned char op = *p++;
+        switch (op) {
+        case DW_LNS_copy:
+            FILL_LINE();
+            break;
+        case DW_LNS_advance_pc:
+            a = uleb128(&p) * header.minimum_instruction_length;
+            addr += a;
+            break;
+        case DW_LNS_advance_line: {
+            long a = sleb128(&p);
+            line += a;
+            break;
+        }
+        case DW_LNS_set_file:
+            file = (unsigned int)uleb128(&p);
+            break;
+        case DW_LNS_set_column:
+            /*column = (unsigned int)*/(void)uleb128(&p);
+            break;
+        case DW_LNS_negate_stmt:
+            is_stmt = !is_stmt;
+            break;
+        case DW_LNS_set_basic_block:
+            /*basic_block = 1; */
+            break;
+        case DW_LNS_const_add_pc:
+            a = ((255UL - header.opcode_base) / header.line_range) *
+                header.minimum_instruction_length;
+            addr += a;
+            break;
+        case DW_LNS_fixed_advance_pc:
+            a = *(uint16_t *)p;
+            p += sizeof(uint16_t);
+            addr += a;
+            break;
+        case DW_LNS_set_prologue_end:
+            /* prologue_end = 1; */
+            break;
+        case DW_LNS_set_epilogue_begin:
+            /* epilogue_begin = 1; */
+            break;
+        case DW_LNS_set_isa:
+            /* isa = (unsigned int)*/(void)uleb128(&p);
+            break;
+        case 0:
+            a = uleb128(&p);
+            op = *p++;
+            switch (op) {
+            case DW_LNE_end_sequence:
+                /* end_sequence = 1; */
+                FILL_LINE();
+                addr = 0;
+                file = 1;
+                line = 1;
+                /* column = 0; */
+                is_stmt = header.default_is_stmt;
+                /* end_sequence = 0; */
+                /* isa = 0; */
+                break;
+            case DW_LNE_set_address:
+                addr = *(unsigned long *)p;
+                p += sizeof(unsigned long);
+                break;
+            case DW_LNE_define_file:
+                kprintf("Unsupported operation in %s\n",
+                        binary_filename);
+                break;
+            case DW_LNE_set_discriminator:
+                /* TODO:currently ignore */
+                uleb128(&p);
+                break;
+            default:
+                kprintf("Unknown extended opcode: %d in %s\n",
+                        op, binary_filename);
+            }
+            break;
+        default: {
             uint8_t adjusted_opcode = op - header.opcode_base;
             uint8_t operation_advance = adjusted_opcode / header.line_range;
             /* NOTE: this code doesn't support VLIW */
             addr += operation_advance * header.minimum_instruction_length;
             line += header.line_base + (adjusted_opcode % header.line_range);
-	    FILL_LINE();
-	}
-	}
+            FILL_LINE();
+        }
+        }
     }
     *debug_line = (char *)p;
     return 0;
@@ -501,17 +556,17 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
 
 static int
 parse_debug_line(int num_traces, void **traces,
-		 char *debug_line, unsigned long size,
-		 obj_info_t *obj, line_info_t *lines, int offset)
+                 const char *debug_line, unsigned long size,
+                 obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
-    char *debug_line_end = debug_line + size;
+    const char *debug_line_end = debug_line + size;
     while (debug_line < debug_line_end) {
-	if (parse_debug_line_cu(num_traces, traces, &debug_line, obj, lines, offset))
-	    return -1;
+        if (parse_debug_line_cu(num_traces, traces, &debug_line, obj, lines, offset, errout))
+            return -1;
     }
     if (debug_line != debug_line_end) {
-	kprintf("Unexpected size of .debug_line in %s\n",
-		binary_filename);
+        kprintf("Unexpected size of .debug_line in %s\n",
+                binary_filename);
     }
     return 0;
 }
@@ -519,7 +574,7 @@ parse_debug_line(int num_traces, void **traces,
 /* read file and fill lines */
 static uintptr_t
 fill_lines(int num_traces, void **traces, int check_debuglink,
-	   obj_info_t **objp, line_info_t *lines, int offset);
+           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout);
 
 static void
 append_obj(obj_info_t **objp)
@@ -530,13 +585,25 @@ append_obj(obj_info_t **objp)
 }
 
 #ifdef USE_ELF
+/* Ideally we should check 4 paths to follow gnu_debuglink:
+ *
+ *   - /usr/lib/debug/.build-id/ab/cdef1234.debug
+ *   - /usr/bin/ruby.debug
+ *   - /usr/bin/.debug/ruby.debug
+ *   - /usr/lib/debug/usr/bin/ruby.debug.
+ *
+ * but we handle only two cases for now as the two formats are
+ * used by some linux distributions.
+ *
+ * See GDB's info for detail.
+ * https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
+ */
+
+// check the path pattern of "/usr/lib/debug/usr/bin/ruby.debug"
 static void
 follow_debuglink(const char *debuglink, int num_traces, void **traces,
-		 obj_info_t **objp, line_info_t *lines, int offset)
+                 obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
-    /* Ideally we should check 4 paths to follow gnu_debuglink,
-       but we handle only one case for now as this format is used
-       by some linux distributions. See GDB's info for detail. */
     static const char global_debug_dir[] = "/usr/lib/debug";
     const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
     char *p;
@@ -545,13 +612,13 @@ follow_debuglink(const char *debuglink, int num_traces, void **traces,
 
     p = strrchr(binary_filename, '/');
     if (!p) {
-	return;
+        return;
     }
     p[1] = '\0';
 
     len = strlen(binary_filename);
     if (len >= PATH_MAX - global_debug_dir_len)
-	len = PATH_MAX - global_debug_dir_len - 1;
+        len = PATH_MAX - global_debug_dir_len - 1;
     memmove(binary_filename + global_debug_dir_len, binary_filename, len);
     memcpy(binary_filename, global_debug_dir, global_debug_dir_len);
     len += global_debug_dir_len;
@@ -561,7 +628,39 @@ follow_debuglink(const char *debuglink, int num_traces, void **traces,
     o2 = *objp;
     o2->base_addr = o1->base_addr;
     o2->path = o1->path;
-    fill_lines(num_traces, traces, 0, objp, lines, offset);
+    fill_lines(num_traces, traces, 0, objp, lines, offset, errout);
+}
+
+// check the path pattern of "/usr/lib/debug/.build-id/ab/cdef1234.debug"
+static void
+follow_debuglink_build_id(const char *build_id, size_t build_id_size, int num_traces, void **traces,
+                          obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
+{
+    static const char global_debug_dir[] = "/usr/lib/debug/.build-id/";
+    static const char debug_suffix[] = ".debug";
+    const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
+    char *p;
+    obj_info_t *o1 = *objp, *o2;
+    size_t i;
+
+    if (PATH_MAX < global_debug_dir_len + build_id_size * 2 + sizeof(debug_suffix)) return;
+
+    memcpy(binary_filename, global_debug_dir, global_debug_dir_len);
+    p = binary_filename + global_debug_dir_len;
+    for (i = 0; i < build_id_size; i++) {
+        static const char tbl[] = "0123456789abcdef";
+        unsigned char n = build_id[i];
+        *p++ = tbl[n / 16];
+        *p++ = tbl[n % 16];
+        if (i == 0) *p++ = '/';
+    }
+    memcpy(p, debug_suffix, sizeof(debug_suffix));
+
+    append_obj(objp);
+    o2 = *objp;
+    o2->base_addr = o1->base_addr;
+    o2->path = o1->path;
+    fill_lines(num_traces, traces, 0, objp, lines, offset, errout);
 }
 #endif
 
@@ -765,7 +864,23 @@ enum
     DW_FORM_addrx1 = 0x29,
     DW_FORM_addrx2 = 0x2a,
     DW_FORM_addrx3 = 0x2b,
-    DW_FORM_addrx4 = 0x2c
+    DW_FORM_addrx4 = 0x2c,
+
+    /* GNU extensions for referring to .gnu_debugaltlink dwz-compressed info */
+    DW_FORM_GNU_ref_alt = 0x1f20,
+    DW_FORM_GNU_strp_alt = 0x1f21
+};
+
+/* Range list entry encodings */
+enum {
+    DW_RLE_end_of_list = 0x00,
+    DW_RLE_base_addressx = 0x01,
+    DW_RLE_startx_endx = 0x02,
+    DW_RLE_startx_length = 0x03,
+    DW_RLE_offset_pair = 0x04,
+    DW_RLE_base_address = 0x05,
+    DW_RLE_start_end = 0x06,
+    DW_RLE_start_length = 0x07
 };
 
 enum {
@@ -773,27 +888,34 @@ enum {
     VAL_cstr = 1,
     VAL_data = 2,
     VAL_uint = 3,
-    VAL_int = 4
+    VAL_int = 4,
+    VAL_addr = 5
 };
 
 # define ABBREV_TABLE_SIZE 256
 typedef struct {
     obj_info_t *obj;
-    char *file;
-    char *current_cu;
+    const char *file;
+    uint8_t current_version;
+    const char *current_cu;
     uint64_t current_low_pc;
-    char *debug_line_cu_end;
-    char *debug_line_files;
-    char *debug_line_directories;
-    char *p;
-    char *cu_end;
-    char *pend;
-    char *q0;
-    char *q;
+    uint64_t current_str_offsets_base;
+    uint64_t current_addr_base;
+    uint64_t current_rnglists_base;
+    const char *debug_line_cu_end;
+    uint8_t debug_line_format;
+    uint16_t debug_line_version;
+    const char *debug_line_files;
+    const char *debug_line_directories;
+    const char *p;
+    const char *cu_end;
+    const char *pend;
+    const char *q0;
+    const char *q;
     int format; // 4 or 8
     uint8_t address_size;
     int level;
-    char *abbrev_table[ABBREV_TABLE_SIZE];
+    const char *abbrev_table[ABBREV_TABLE_SIZE];
 } DebugInfoReader;
 
 typedef struct {
@@ -804,9 +926,10 @@ typedef struct {
 
 typedef struct {
     union {
-        char *ptr;
+        const char *ptr;
         uint64_t uint64;
         int64_t int64;
+        uint64_t addr_idx;
     } as;
     uint64_t off;
     uint64_t at;
@@ -815,8 +938,11 @@ typedef struct {
     int type;
 } DebugInfoValue;
 
-/* TODO: Big Endian */
+#if defined(WORDS_BIGENDIAN)
+#define MERGE_2INTS(a,b,sz) (((uint64_t)(a)<<sz)|(b))
+#else
 #define MERGE_2INTS(a,b,sz) (((uint64_t)(b)<<sz)|(a))
+#endif
 
 static uint16_t
 get_uint16(const uint8_t *p)
@@ -837,39 +963,39 @@ get_uint64(const uint8_t *p)
 }
 
 static uint8_t
-read_uint8(char **ptr)
+read_uint8(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 1);
-    return *p;
+    const char *p = *ptr;
+    *ptr = (p + 1);
+    return (uint8_t)*p;
 }
 
 static uint16_t
-read_uint16(char **ptr)
+read_uint16(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 2);
-    return get_uint16(p);
+    const char *p = *ptr;
+    *ptr = (p + 2);
+    return get_uint16((const uint8_t *)p);
 }
 
 static uint32_t
-read_uint24(char **ptr)
+read_uint24(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 3);
-    return (*p << 16) | get_uint16(p+1);
+    const char *p = *ptr;
+    *ptr = (p + 3);
+    return ((uint8_t)*p << 16) | get_uint16((const uint8_t *)p+1);
 }
 
 static uint32_t
-read_uint32(char **ptr)
+read_uint32(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 4);
-    return get_uint32(p);
+    const char *p = *ptr;
+    *ptr = (p + 4);
+    return get_uint32((const uint8_t *)p);
 }
 
 static uint64_t
-read_uint64(char **ptr)
+read_uint64(const char **ptr)
 {
     const unsigned char *p = (const unsigned char *)*ptr;
     *ptr = (char *)(p + 8);
@@ -877,7 +1003,7 @@ read_uint64(char **ptr)
 }
 
 static uintptr_t
-read_uintptr(char **ptr)
+read_uintptr(const char **ptr)
 {
     const unsigned char *p = (const unsigned char *)*ptr;
     *ptr = (char *)(p + SIZEOF_VOIDP);
@@ -918,13 +1044,34 @@ debug_info_reader_init(DebugInfoReader *reader, obj_info_t *obj)
     reader->p = obj->debug_info.ptr;
     reader->pend = obj->debug_info.ptr + obj->debug_info.size;
     reader->debug_line_cu_end = obj->debug_line.ptr;
+    reader->current_low_pc = 0;
+    reader->current_str_offsets_base = 0;
+    reader->current_addr_base = 0;
+    reader->current_rnglists_base = 0;
+}
+
+static void
+di_skip_die_attributes(const char **p)
+{
+    for (;;) {
+        uint64_t at = uleb128(p);
+        uint64_t form = uleb128(p);
+        if (!at && !form) break;
+        switch (form) {
+          default:
+            break;
+          case DW_FORM_implicit_const:
+            sleb128(p);
+            break;
+        }
+    }
 }
 
 static void
 di_read_debug_abbrev_cu(DebugInfoReader *reader)
 {
     uint64_t prev = 0;
-    char *p = reader->q0;
+    const char *p = reader->q0;
     for (;;) {
         uint64_t abbrev_number = uleb128(&p);
         if (abbrev_number <= prev) break;
@@ -934,26 +1081,23 @@ di_read_debug_abbrev_cu(DebugInfoReader *reader)
         prev = abbrev_number;
         uleb128(&p); /* tag */
         p++; /* has_children */
-        /* skip content */
-        for (;;) {
-            uint64_t at = uleb128(&p);
-            uint64_t form = uleb128(&p);
-            if (!at && !form) break;
-        }
+        di_skip_die_attributes(&p);
     }
 }
 
 static int
-di_read_debug_line_cu(DebugInfoReader *reader)
+di_read_debug_line_cu(DebugInfoReader *reader, FILE *errout)
 {
     const char *p;
     struct LineNumberProgramHeader header;
 
     p = (const char *)reader->debug_line_cu_end;
-    if (parse_debug_line_header(&p, &header))
+    if (parse_debug_line_header(reader->obj, &p, &header, errout))
         return -1;
 
     reader->debug_line_cu_end = (char *)header.cu_end;
+    reader->debug_line_format = header.format;
+    reader->debug_line_version = header.version;
     reader->debug_line_directories = (char *)header.include_directories;
     reader->debug_line_files = (char *)header.filenames;
 
@@ -961,6 +1105,13 @@ di_read_debug_line_cu(DebugInfoReader *reader)
 }
 
 static void
+set_addr_idx_value(DebugInfoValue *v, uint64_t n)
+{
+    v->as.addr_idx = n;
+    v->type = VAL_addr;
+}
+
+static void
 set_uint_value(DebugInfoValue *v, uint64_t n)
 {
     v->as.uint64 = n;
@@ -975,7 +1126,7 @@ set_int_value(DebugInfoValue *v, int64_t n)
 }
 
 static void
-set_cstr_value(DebugInfoValue *v, char *s)
+set_cstr_value(DebugInfoValue *v, const char *s)
 {
     v->as.ptr = s;
     v->off = 0;
@@ -983,7 +1134,7 @@ set_cstr_value(DebugInfoValue *v, char *s)
 }
 
 static void
-set_cstrp_value(DebugInfoValue *v, char *s, uint64_t off)
+set_cstrp_value(DebugInfoValue *v, const char *s, uint64_t off)
 {
     v->as.ptr = s;
     v->off = off;
@@ -991,7 +1142,7 @@ set_cstrp_value(DebugInfoValue *v, char *s, uint64_t off)
 }
 
 static void
-set_data_value(DebugInfoValue *v, char *s)
+set_data_value(DebugInfoValue *v, const char *s)
 {
     v->as.ptr = s;
     v->type = VAL_data;
@@ -1007,19 +1158,46 @@ get_cstr_value(DebugInfoValue *v)
     }
 }
 
-static void
-debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoValue *v)
+static const char *
+resolve_strx(DebugInfoReader *reader, uint64_t idx)
+{
+    const char *p = reader->obj->debug_str_offsets.ptr + reader->current_str_offsets_base;
+    uint64_t off;
+    if (reader->format == 4) {
+        off = ((uint32_t *)p)[idx];
+    }
+    else {
+        off = ((uint64_t *)p)[idx];
+    }
+    return reader->obj->debug_str.ptr + off;
+}
+
+static bool
+debug_info_reader_read_addr_value_member(DebugInfoReader *reader, DebugInfoValue *v, int size)
+{
+    if (size == 4) {
+        set_uint_value(v, read_uint32(&reader->p));
+    } else if (size == 8) {
+        set_uint_value(v, read_uint64(&reader->p));
+    } else {
+        return false;
+    }
+    return true;
+}
+
+#define debug_info_reader_read_addr_value(reader, v, mem) \
+    if (!debug_info_reader_read_addr_value_member((reader), (v), (reader)->mem)) { \
+        kprintf("unknown " #mem ":%d", (reader)->mem); \
+        return false; \
+    }
+
+
+static bool
+debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoValue *v, FILE *errout)
 {
     switch (form) {
       case DW_FORM_addr:
-        if (reader->address_size == 4) {
-            set_uint_value(v, read_uint32(&reader->p));
-        } else if (reader->address_size == 8) {
-            set_uint_value(v, read_uint64(&reader->p));
-        } else {
-            fprintf(stderr,"unknown address_size:%d", reader->address_size);
-            abort();
-        }
+        debug_info_reader_read_addr_value(reader, v, address_size);
         break;
       case DW_FORM_block2:
         v->size = read_uint16(&reader->p);
@@ -1071,13 +1249,12 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         set_uint_value(v, read_uleb128(reader));
         break;
       case DW_FORM_ref_addr:
-        if (reader->address_size == 4) {
-            set_uint_value(v, read_uint32(&reader->p));
-        } else if (reader->address_size == 8) {
-            set_uint_value(v, read_uint64(&reader->p));
+        if (reader->current_version <= 2) {
+            // DWARF Version 2 specifies that references have
+            // the same size as an address on the target system
+            debug_info_reader_read_addr_value(reader, v, address_size);
         } else {
-            fprintf(stderr,"unknown address_size:%d", reader->address_size);
-            abort();
+            debug_info_reader_read_addr_value(reader, v, format);
         }
         break;
       case DW_FORM_ref1:
@@ -1119,11 +1296,10 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         set_uint_value(v, 1);
         break;
       case DW_FORM_strx:
-        set_uint_value(v, uleb128(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, uleb128(&reader->p)));
         break;
       case DW_FORM_addrx:
-        /* TODO: read .debug_addr */
-        set_uint_value(v, uleb128(&reader->p));
+        set_addr_idx_value(v, uleb128(&reader->p));
         break;
       case DW_FORM_ref_sup4:
         set_uint_value(v, read_uint32(&reader->p));
@@ -1138,8 +1314,7 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         reader->p += v->size;
         break;
       case DW_FORM_line_strp:
-        set_uint_value(v, read_uint(reader));
-        /* *p = reader->file + reader->line->sh_offset + ret; */
+        set_cstrp_value(v, reader->obj->debug_line_str.ptr, read_uint(reader));
         break;
       case DW_FORM_ref_sig8:
         set_uint_value(v, read_uint64(&reader->p));
@@ -1157,45 +1332,53 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         set_uint_value(v, read_uint64(&reader->p));
         break;
       case DW_FORM_strx1:
-        set_uint_value(v, read_uint8(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint8(&reader->p)));
         break;
       case DW_FORM_strx2:
-        set_uint_value(v, read_uint16(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint16(&reader->p)));
         break;
       case DW_FORM_strx3:
-        set_uint_value(v, read_uint24(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint24(&reader->p)));
         break;
       case DW_FORM_strx4:
-        set_uint_value(v, read_uint32(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint32(&reader->p)));
         break;
       case DW_FORM_addrx1:
-        set_uint_value(v, read_uint8(&reader->p));
+        set_addr_idx_value(v, read_uint8(&reader->p));
         break;
       case DW_FORM_addrx2:
-        set_uint_value(v, read_uint16(&reader->p));
+        set_addr_idx_value(v, read_uint16(&reader->p));
         break;
       case DW_FORM_addrx3:
-        set_uint_value(v, read_uint24(&reader->p));
+        set_addr_idx_value(v, read_uint24(&reader->p));
         break;
       case DW_FORM_addrx4:
-        set_uint_value(v, read_uint32(&reader->p));
+        set_addr_idx_value(v, read_uint32(&reader->p));
+        break;
+      /* we have no support for actually reading the real values of these refs out
+       * of the .gnu_debugaltlink dwz-compressed debuginfo at the moment, but "read"
+       * them anyway so that we advance the reader by the right amount. */
+      case DW_FORM_GNU_ref_alt:
+      case DW_FORM_GNU_strp_alt:
+        read_uint(reader);
+        set_uint_value(v, 0);
         break;
       case 0:
         goto fail;
         break;
     }
-    return;
+    return true;
 
   fail:
-    fprintf(stderr, "%d: unsupported form: %#"PRIx64"\n", __LINE__, form);
-    exit(1);
+    kprintf("%d: unsupported form: %#"PRIx64"\n", __LINE__, form);
+    return false;
 }
 
 /* find abbrev in current compilation unit */
-static char *
-di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
+static const char *
+di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number, FILE *errout)
 {
-    char *p;
+    const char *p;
     if (abbrev_number < ABBREV_TABLE_SIZE) {
         return reader->abbrev_table[abbrev_number];
     }
@@ -1203,77 +1386,67 @@ di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
     /* skip 255th record */
     uleb128(&p); /* tag */
     p++; /* has_children */
-    /* skip content */
-    for (;;) {
-        uint64_t at = uleb128(&p);
-        uint64_t form = uleb128(&p);
-        if (!at && !form) break;
-    }
+    di_skip_die_attributes(&p);
     for (uint64_t n = uleb128(&p); abbrev_number != n; n = uleb128(&p)) {
         if (n == 0) {
-            fprintf(stderr,"%d: Abbrev Number %"PRId64" not found\n",__LINE__, abbrev_number);
-            exit(1);
+            kprintf("%d: Abbrev Number %"PRId64" not found\n",__LINE__, abbrev_number);
+            return NULL;
         }
         uleb128(&p); /* tag */
         p++; /* has_children */
-        /* skip content */
-        for (;;) {
-            uint64_t at = uleb128(&p);
-            uint64_t form = uleb128(&p);
-            if (!at && !form) break;
-        }
+        di_skip_die_attributes(&p);
     }
     return p;
 }
 
 #if 0
 static void
-hexdump0(const unsigned char *p, size_t n)
+hexdump0(const unsigned char *p, size_t n, FILE *errout)
 {
     size_t i;
-    fprintf(stderr, "     0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F\n");
+    kprintf("     0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F\n");
     for (i=0; i < n; i++){
         switch (i & 15) {
           case 0:
-            fprintf(stderr, "%02zd: %02X ", i/16, p[i]);
+            kprintf("%02" PRIdSIZE ": %02X ", i/16, p[i]);
             break;
           case 15:
-            fprintf(stderr, "%02X\n", p[i]);
+            kprintf("%02X\n", p[i]);
             break;
           default:
-            fprintf(stderr, "%02X ", p[i]);
+            kprintf("%02X ", p[i]);
             break;
         }
     }
     if ((i & 15) != 15) {
-        fprintf(stderr, "\n");
+        kprintf("\n");
     }
 }
-#define hexdump(p,n) hexdump0((const unsigned char *)p, n)
+#define hexdump(p,n,e) hexdump0((const unsigned char *)p, n, e)
 
 static void
-div_inspect(DebugInfoValue *v)
+div_inspect(DebugInfoValue *v, FILE *errout)
 {
     switch (v->type) {
       case VAL_uint:
-        fprintf(stderr,"%d: type:%d size:%zx v:%lx\n",__LINE__,v->type,v->size,v->as.uint64);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:%"PRIx64"\n",__LINE__,v->type,v->size,v->as.uint64);
         break;
       case VAL_int:
-        fprintf(stderr,"%d: type:%d size:%zx v:%ld\n",__LINE__,v->type,v->size,(int64_t)v->as.uint64);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:%"PRId64"\n",__LINE__,v->type,v->size,(int64_t)v->as.uint64);
         break;
       case VAL_cstr:
-        fprintf(stderr,"%d: type:%d size:%zx v:'%s'\n",__LINE__,v->type,v->size,v->as.ptr);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:'%s'\n",__LINE__,v->type,v->size,v->as.ptr);
         break;
       case VAL_data:
-        fprintf(stderr,"%d: type:%d size:%zx v:\n",__LINE__,v->type,v->size);
-        hexdump(v->as.ptr, 16);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:\n",__LINE__,v->type,v->size);
+        hexdump(v->as.ptr, 16, errout);
         break;
     }
 }
 #endif
 
 static DIE *
-di_read_die(DebugInfoReader *reader, DIE *die)
+di_read_die(DebugInfoReader *reader, DIE *die, FILE *errout)
 {
     uint64_t abbrev_number = uleb128(&reader->p);
     if (abbrev_number == 0) {
@@ -1281,7 +1454,7 @@ di_read_die(DebugInfoReader *reader, DIE *die)
         return NULL;
     }
 
-    reader->q = di_find_abbrev(reader, abbrev_number);
+    if (!(reader->q = di_find_abbrev(reader, abbrev_number, errout))) return NULL;
 
     die->pos = reader->p - reader->obj->debug_info.ptr - 1;
     die->tag = (int)uleb128(&reader->q); /* tag */
@@ -1293,27 +1466,109 @@ di_read_die(DebugInfoReader *reader, DIE *die)
 }
 
 static DebugInfoValue *
-di_read_record(DebugInfoReader *reader, DebugInfoValue *vp)
+di_read_record(DebugInfoReader *reader, DebugInfoValue *vp, FILE *errout)
 {
     uint64_t at = uleb128(&reader->q);
     uint64_t form = uleb128(&reader->q);
     if (!at || !form) return NULL;
     vp->at = at;
     vp->form = form;
-    debug_info_reader_read_value(reader, form, vp);
+    if (!debug_info_reader_read_value(reader, form, vp, errout)) return NULL;
     return vp;
 }
 
-static void
-di_skip_records(DebugInfoReader *reader)
+static bool
+di_skip_records(DebugInfoReader *reader, FILE *errout)
 {
     for (;;) {
-        DebugInfoValue v = {{}};
+        DebugInfoValue v = {{0}};
         uint64_t at = uleb128(&reader->q);
         uint64_t form = uleb128(&reader->q);
-        if (!at || !form) return;
-        debug_info_reader_read_value(reader, form, &v);
+        if (!at || !form) return true;
+        if (!debug_info_reader_read_value(reader, form, &v, errout)) return false;
+    }
+}
+
+typedef struct addr_header {
+    const char *ptr;
+    uint64_t unit_length;
+    uint8_t format;
+    uint8_t address_size;
+    /* uint8_t segment_selector_size; */
+} addr_header_t;
+
+static bool
+addr_header_init(obj_info_t *obj, addr_header_t *header, FILE *errout)
+{
+    const char *p = obj->debug_addr.ptr;
+
+    header->ptr = p;
+
+    if (!p) return true;
+
+    header->unit_length = *(uint32_t *)p;
+    p += sizeof(uint32_t);
+
+    header->format = 4;
+    if (header->unit_length == 0xffffffff) {
+        header->unit_length = *(uint64_t *)p;
+        p += sizeof(uint64_t);
+        header->format = 8;
+    }
+
+    p += 2; /* version */
+    header->address_size = *p++;
+    if (header->address_size != 4 && header->address_size != 8) {
+        kprintf("unknown address_size:%d", header->address_size);
+        return false;
+    }
+    p++; /* segment_selector_size */
+    return true;
+}
+
+static uint64_t
+read_addr(addr_header_t *header, uint64_t addr_base, uint64_t idx) {
+    if (header->address_size == 4) {
+        return ((uint32_t*)(header->ptr + addr_base))[idx];
+    }
+    else {
+        return ((uint64_t*)(header->ptr + addr_base))[idx];
+    }
+}
+
+typedef struct rnglists_header {
+    uint64_t unit_length;
+    uint8_t format;
+    uint8_t address_size;
+    uint32_t offset_entry_count;
+} rnglists_header_t;
+
+static bool
+rnglists_header_init(obj_info_t *obj, rnglists_header_t *header, FILE *errout)
+{
+    const char *p = obj->debug_rnglists.ptr;
+
+    if (!p) return true;
+
+    header->unit_length = *(uint32_t *)p;
+    p += sizeof(uint32_t);
+
+    header->format = 4;
+    if (header->unit_length == 0xffffffff) {
+        header->unit_length = *(uint64_t *)p;
+        p += sizeof(uint64_t);
+        header->format = 8;
+    }
+
+    p += 2; /* version */
+    header->address_size = *p++;
+    if (header->address_size != 4 && header->address_size != 8) {
+        kprintf("unknown address_size:%d", header->address_size);
+        return false;
     }
+    p++; /* segment_selector_size */
+    header->offset_entry_count = *(uint32_t *)p;
+    return true;
 }
 
 typedef struct {
@@ -1326,35 +1581,54 @@ typedef struct {
 } ranges_t;
 
 static void
-ranges_set(ranges_t *ptr, DebugInfoValue *v)
+ranges_set(ranges_t *ptr, DebugInfoValue *v, addr_header_t *addr_header, uint64_t addr_base)
 {
+    uint64_t n = 0;
+    if (v->type == VAL_uint) {
+        n = v->as.uint64;
+    }
+    else if (v->type == VAL_addr) {
+        n = read_addr(addr_header, addr_base, v->as.addr_idx);
+    }
     switch (v->at) {
       case DW_AT_low_pc:
-        ptr->low_pc = v->as.uint64;
+        ptr->low_pc = n;
         ptr->low_pc_set = true;
         break;
       case DW_AT_high_pc:
         if (v->form == DW_FORM_addr) {
-            ptr->high_pc = v->as.uint64;
+            ptr->high_pc = n;
         }
         else {
-            ptr->high_pc = ptr->low_pc + v->as.uint64;
+            ptr->high_pc = ptr->low_pc + n;
         }
         ptr->high_pc_set = true;
         break;
       case DW_AT_ranges:
-        ptr->ranges = v->as.uint64;
+        ptr->ranges = n;
         ptr->ranges_set = true;
         break;
     }
 }
 
+static uint64_t
+read_dw_form_addr(DebugInfoReader *reader, const char **ptr, FILE *errout)
+{
+    const char *p = *ptr;
+    *ptr = p + reader->address_size;
+    if (reader->address_size == 4) {
+        return read_uint32(&p);
+    } else {
+        return read_uint64(&p);
+    }
+}
+
 static uintptr_t
-ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
+ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_header_t *rnglists_header, FILE *errout)
 {
     if (ptr->high_pc_set) {
         if (ptr->ranges_set || !ptr->low_pc_set) {
-            exit(1);
+            return UINTPTR_MAX;
         }
         if (ptr->low_pc <= addr && addr <= ptr->high_pc) {
             return (uintptr_t)ptr->low_pc;
@@ -1362,8 +1636,66 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
     }
     else if (ptr->ranges_set) {
         /* TODO: support base address selection entry */
-        char *p = reader->obj->debug_ranges.ptr + ptr->ranges;
+        const char *p;
         uint64_t base = ptr->low_pc_set ? ptr->low_pc : reader->current_low_pc;
+        bool base_valid = true;
+        if (reader->current_version >= 5) {
+            if (rnglists_header->offset_entry_count == 0) {
+                // DW_FORM_sec_offset
+                p = reader->obj->debug_rnglists.ptr + ptr->ranges + reader->current_rnglists_base;
+            }
+            else {
+                // DW_FORM_rnglistx
+                const char *offset_array = reader->obj->debug_rnglists.ptr + reader->current_rnglists_base;
+                if (rnglists_header->format == 4) {
+                    p = offset_array + ((uint32_t *)offset_array)[ptr->ranges];
+                }
+                else {
+                    p = offset_array + ((uint64_t *)offset_array)[ptr->ranges];
+                }
+            }
+            for (;;) {
+                uint8_t rle = read_uint8(&p);
+                uintptr_t from = 0, to = 0;
+                if (rle == DW_RLE_end_of_list) break;
+                switch (rle) {
+                  case DW_RLE_base_addressx:
+                    uleb128(&p);
+                    base_valid = false; /* not supported yet */
+                    break;
+                  case DW_RLE_startx_endx:
+                    uleb128(&p);
+                    uleb128(&p);
+                    break;
+                  case DW_RLE_startx_length:
+                    uleb128(&p);
+                    uleb128(&p);
+                    break;
+                  case DW_RLE_offset_pair:
+                    if (!base_valid) break;
+                    from = (uintptr_t)base + uleb128(&p);
+                    to = (uintptr_t)base + uleb128(&p);
+                    break;
+                  case DW_RLE_base_address:
+                    base = read_dw_form_addr(reader, &p, errout);
+                    base_valid = true;
+                    break;
+                  case DW_RLE_start_end:
+                    from = (uintptr_t)read_dw_form_addr(reader, &p, errout);
+                    to = (uintptr_t)read_dw_form_addr(reader, &p, errout);
+                    break;
+                  case DW_RLE_start_length:
+                    from = (uintptr_t)read_dw_form_addr(reader, &p, errout);
+                    to = from + uleb128(&p);
+                    break;
+                }
+                if (from <= addr && addr < to) {
+                    return from;
+                }
+            }
+            return 0;
+        }
+        p = reader->obj->debug_ranges.ptr + ptr->ranges;
         for (;;) {
             uintptr_t from = read_uintptr(&p);
             uintptr_t to = read_uintptr(&p);
@@ -1373,7 +1705,7 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
                 base = to;
             }
             else if (base + from <= addr && addr < base + to) {
-                return from;
+                return (uintptr_t)base + from;
             }
         }
     }
@@ -1382,42 +1714,42 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
             return (uintptr_t)ptr->low_pc;
         }
     }
-    return false;
+    return 0;
 }
 
 #if 0
 static void
-ranges_inspect(DebugInfoReader *reader, ranges_t *ptr)
+ranges_inspect(DebugInfoReader *reader, ranges_t *ptr, FILE *errout)
 {
     if (ptr->high_pc_set) {
         if (ptr->ranges_set || !ptr->low_pc_set) {
-            fprintf(stderr,"low_pc_set:%d high_pc_set:%d ranges_set:%d\n",ptr->low_pc_set,ptr->high_pc_set,ptr->ranges_set);
-            exit(1);
+            kprintf("low_pc_set:%d high_pc_set:%d ranges_set:%d\n",ptr->low_pc_set,ptr->high_pc_set,ptr->ranges_set);
+            return;
         }
-        fprintf(stderr,"low_pc:%"PRIx64" high_pc:%"PRIx64"\n",ptr->low_pc,ptr->high_pc);
+        kprintf("low_pc:%"PRIx64" high_pc:%"PRIx64"\n",ptr->low_pc,ptr->high_pc);
     }
     else if (ptr->ranges_set) {
         char *p = reader->obj->debug_ranges.ptr + ptr->ranges;
-        fprintf(stderr,"low_pc:%"PRIx64" ranges:%"PRIx64" %lx ",ptr->low_pc,ptr->ranges, p-reader->obj->mapped);
+        kprintf("low_pc:%"PRIx64" ranges:%"PRIx64" %lx ",ptr->low_pc,ptr->ranges, p-reader->obj->mapped);
         for (;;) {
             uintptr_t from = read_uintptr(&p);
             uintptr_t to = read_uintptr(&p);
             if (!from && !to) break;
-            fprintf(stderr,"%"PRIx64"-%"PRIx64" ",ptr->low_pc+from,ptr->low_pc+to);
+            kprintf("%"PRIx64"-%"PRIx64" ",ptr->low_pc+from,ptr->low_pc+to);
         }
-        fprintf(stderr,"\n");
+        kprintf("\n");
     }
     else if (ptr->low_pc_set) {
-        fprintf(stderr,"low_pc:%"PRIx64"\n",ptr->low_pc);
+        kprintf("low_pc:%"PRIx64"\n",ptr->low_pc);
     }
     else {
-        fprintf(stderr,"empty\n");
+        kprintf("empty\n");
     }
 }
 #endif
 
 static int
-di_read_cu(DebugInfoReader *reader)
+di_read_cu(DebugInfoReader *reader, FILE *errout)
 {
     uint64_t unit_length;
     uint16_t version;
@@ -1431,6 +1763,7 @@ di_read_cu(DebugInfoReader *reader)
     }
     reader->cu_end = reader->p + unit_length;
     version = read_uint16(&reader->p);
+    reader->current_version = version;
     if (version > 5) {
         return -1;
     }
@@ -1443,56 +1776,102 @@ di_read_cu(DebugInfoReader *reader)
         debug_abbrev_offset = read_uint(reader);
         reader->address_size = read_uint8(&reader->p);
     }
+    if (reader->address_size != 4 && reader->address_size != 8) {
+        kprintf("unknown address_size:%d", reader->address_size);
+        return -1;
+    }
     reader->q0 = reader->obj->debug_abbrev.ptr + debug_abbrev_offset;
 
     reader->level = 0;
     di_read_debug_abbrev_cu(reader);
-    if (di_read_debug_line_cu(reader)) return -1;
+    if (di_read_debug_line_cu(reader, errout)) return -1;
 
-#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER_BUILD_DATE)
-    /* Though DWARF specifies "the applicable base address defaults to the base
-       address of the compilation unit", but GCC seems to use zero as default */
-#else
     do {
         DIE die;
 
-        if (!di_read_die(reader, &die)) continue;
+        if (!di_read_die(reader, &die, errout)) continue;
 
         if (die.tag != DW_TAG_compile_unit) {
-            di_skip_records(reader);
+            if (!di_skip_records(reader, errout)) return -1;
             break;
         }
 
+        reader->current_str_offsets_base = 0;
+        reader->current_addr_base = 0;
+        reader->current_rnglists_base = 0;
+
+        DebugInfoValue low_pc = {{0}};
         /* enumerate abbrev */
         for (;;) {
-            DebugInfoValue v = {{}};
-            if (!di_read_record(reader, &v)) break;
+            DebugInfoValue v = {{0}};
+            if (!di_read_record(reader, &v, errout)) break;
             switch (v.at) {
               case DW_AT_low_pc:
-                reader->current_low_pc = v.as.uint64;
+                // clang may output DW_AT_addr_base after DW_AT_low_pc.
+                // We need to resolve the DW_FORM_addr* after DW_AT_addr_base is parsed.
+                low_pc = v;
+                break;
+              case DW_AT_str_offsets_base:
+                reader->current_str_offsets_base = v.as.uint64;
+                break;
+              case DW_AT_addr_base:
+                reader->current_addr_base = v.as.uint64;
+                break;
+              case DW_AT_rnglists_base:
+                reader->current_rnglists_base = v.as.uint64;
                 break;
             }
         }
+        // Resolve the DW_FORM_addr of DW_AT_low_pc
+        switch (low_pc.type) {
+            case VAL_uint:
+                reader->current_low_pc = low_pc.as.uint64;
+                break;
+            case VAL_addr:
+                {
+                    addr_header_t header = {0};
+                    if (!addr_header_init(reader->obj, &header, errout)) return -1;
+                    reader->current_low_pc = read_addr(&header, reader->current_addr_base, low_pc.as.addr_idx);
+                }
+                break;
+        }
     } while (0);
-#endif
+
     return 0;
 }
 
 static void
-read_abstract_origin(DebugInfoReader *reader, uint64_t abstract_origin, line_info_t *line)
+read_abstract_origin(DebugInfoReader *reader, uint64_t form, uint64_t abstract_origin, line_info_t *line, FILE *errout)
 {
-    char *p = reader->p;
-    char *q = reader->q;
+    const char *p = reader->p;
+    const char *q = reader->q;
     int level = reader->level;
     DIE die;
 
-    reader->p = reader->current_cu + abstract_origin;
-    if (!di_read_die(reader, &die)) goto finish;
+    switch (form) {
+      case DW_FORM_ref1:
+      case DW_FORM_ref2:
+      case DW_FORM_ref4:
+      case DW_FORM_ref8:
+      case DW_FORM_ref_udata:
+        reader->p = reader->current_cu + abstract_origin;
+        break;
+      case DW_FORM_ref_addr:
+        goto finish; /* not supported yet */
+      case DW_FORM_ref_sig8:
+        goto finish; /* not supported yet */
+      case DW_FORM_ref_sup4:
+      case DW_FORM_ref_sup8:
+        goto finish; /* not supported yet */
+      default:
+        goto finish;
+    }
+    if (!di_read_die(reader, &die, errout)) goto finish;
 
     /* enumerate abbrev */
     for (;;) {
-        DebugInfoValue v = {{}};
-        if (!di_read_record(reader, &v)) break;
+        DebugInfoValue v = {{0}};
+        if (!di_read_record(reader, &v, errout)) break;
         switch (v.at) {
           case DW_AT_name:
             line->sname = get_cstr_value(&v);
@@ -1506,36 +1885,44 @@ read_abstract_origin(DebugInfoReader *reader, uint64_t abstract_origin, line_inf
     reader->level = level;
 }
 
-static void
+static bool
 debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
-         line_info_t *lines, int offset) {
+                line_info_t *lines, int offset, FILE *errout)
+{
+
+    addr_header_t addr_header = {0};
+    if (!addr_header_init(reader->obj, &addr_header, errout)) return false;
+
+    rnglists_header_t rnglists_header = {0};
+    if (!rnglists_header_init(reader->obj, &rnglists_header, errout)) return false;
+
     while (reader->p < reader->cu_end) {
         DIE die;
-        ranges_t ranges = {};
-        line_info_t line = {};
+        ranges_t ranges = {0};
+        line_info_t line = {0};
 
-        if (!di_read_die(reader, &die)) continue;
-        /* fprintf(stderr,"%d:%tx: <%d>\n",__LINE__,die.pos,reader->level,die.tag); */
+        if (!di_read_die(reader, &die, errout)) continue;
+        /* kprintf("%d:%tx: <%d>\n",__LINE__,die.pos,reader->level,die.tag); */
 
         if (die.tag != DW_TAG_subprogram && die.tag != DW_TAG_inlined_subroutine) {
           skip_die:
-            di_skip_records(reader);
+            if (!di_skip_records(reader, errout)) return false;
             continue;
         }
 
         /* enumerate abbrev */
         for (;;) {
-            DebugInfoValue v = {{}};
+            DebugInfoValue v = {{0}};
             /* ptrdiff_t pos = reader->p - reader->p0; */
-            if (!di_read_record(reader, &v)) break;
-            /* fprintf(stderr,"\n%d:%tx: AT:%lx FORM:%lx\n",__LINE__,pos,v.at,v.form); */
-            /* div_inspect(&v); */
+            if (!di_read_record(reader, &v, errout)) break;
+            /* kprintf("\n%d:%tx: AT:%lx FORM:%lx\n",__LINE__,pos,v.at,v.form); */
+            /* div_inspect(&v, errout); */
             switch (v.at) {
               case DW_AT_name:
                 line.sname = get_cstr_value(&v);
                 break;
               case DW_AT_call_file:
-                fill_filename((int)v.as.uint64, reader->debug_line_directories, reader->debug_line_files, &line, reader->obj);
+                fill_filename((int)v.as.uint64, reader->debug_line_format, reader->debug_line_version, reader->debug_line_directories, reader->debug_line_files, &line, reader->obj, errout);
                 break;
               case DW_AT_call_line:
                 line.line = (int)v.as.uint64;
@@ -1543,7 +1930,7 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
               case DW_AT_low_pc:
               case DW_AT_high_pc:
               case DW_AT_ranges:
-                ranges_set(&ranges, &v);
+                ranges_set(&ranges, &v, &addr_header, reader->current_addr_base);
                 break;
               case DW_AT_declaration:
                 goto skip_die;
@@ -1551,18 +1938,19 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
                 /* 1 or 3 */
                 break; /* goto skip_die; */
               case DW_AT_abstract_origin:
-                read_abstract_origin(reader, v.as.uint64, &line);
+                read_abstract_origin(reader, v.form, v.as.uint64, &line, errout);
                 break; /* goto skip_die; */
             }
         }
-        /* ranges_inspect(reader, &ranges); */
-        /* fprintf(stderr,"%d:%tx: %x ",__LINE__,diepos,die.tag); */
+        /* ranges_inspect(reader, &ranges, errout); */
+        /* kprintf("%d:%tx: %x ",__LINE__,diepos,die.tag); */
         for (int i=offset; i < num_traces; i++) {
             uintptr_t addr = (uintptr_t)traces[i];
             uintptr_t offset = addr - reader->obj->base_addr + reader->obj->vmaddr;
-            uintptr_t saddr = ranges_include(reader, &ranges, offset);
+            uintptr_t saddr = ranges_include(reader, &ranges, offset, &rnglists_header, errout);
+            if (saddr == UINTPTR_MAX) return false;
             if (saddr) {
-                /* fprintf(stderr, "%d:%tx: %d %lx->%lx %x %s: %s/%s %d %s %s %s\n",__LINE__,die.pos, i,addr,offset, die.tag,line.sname,line.dirname,line.filename,line.line,reader->obj->path,line.sname,lines[i].sname); */
+                /* kprintf("%d:%tx: %d %lx->%lx %x %s: %s/%s %d %s %s %s\n",__LINE__,die.pos, i,addr,offset, die.tag,line.sname,line.dirname,line.filename,line.line,reader->obj->path,line.sname,lines[i].sname); */
                 if (lines[i].sname) {
                     line_info_t *lp = malloc(sizeof(line_info_t));
                     memcpy(lp, &lines[i], sizeof(line_info_t));
@@ -1579,32 +1967,86 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
             }
         }
     }
+    return true;
+}
+
+// This function parses the following attributes of Line Number Program Header in DWARF 5:
+//
+// * directory_entry_format_count
+// * directory_entry_format
+// * directories_count
+// * directories
+//
+// or
+//
+// * file_name_entry_format_count
+// * file_name_entry_format
+// * file_names_count
+// * file_names
+//
+// It records DW_LNCT_path and DW_LNCT_directory_index at the index "idx".
+static const char *
+parse_ver5_debug_line_header(const char *p, int idx, uint8_t format,
+                             obj_info_t *obj, const char **out_path,
+                             uint64_t *out_directory_index, FILE *errout)
+{
+    int i, j;
+    int entry_format_count = *(uint8_t *)p++;
+    const char *entry_format = p;
+
+    /* skip the part of entry_format */
+    for (i = 0; i < entry_format_count * 2; i++) uleb128(&p);
+
+    int entry_count = (int)uleb128(&p);
+
+    DebugInfoReader reader = {0};
+    debug_info_reader_init(&reader, obj);
+    reader.format = format;
+    reader.p = p;
+    for (j = 0; j < entry_count; j++) {
+        const char *format = entry_format;
+        for (i = 0; i < entry_format_count; i++) {
+            DebugInfoValue v = {{0}};
+            unsigned long dw_lnct = uleb128(&format);
+            unsigned long dw_form = uleb128(&format);
+            if (!debug_info_reader_read_value(&reader, dw_form, &v, errout)) return 0;
+            if (dw_lnct == 1 /* DW_LNCT_path */ && v.type == VAL_cstr && out_path)
+                *out_path = v.as.ptr + v.off;
+            if (dw_lnct == 2 /* DW_LNCT_directory_index */ && v.type == VAL_uint && out_directory_index)
+                *out_directory_index = v.as.uint64;
+        }
+        if (j == idx) return 0;
+    }
+
+    return reader.p;
 }
 
 #ifdef USE_ELF
 static unsigned long
 uncompress_debug_section(ElfW(Shdr) *shdr, char *file, char **ptr)
 {
+    *ptr = NULL;
 #ifdef SUPPORT_COMPRESSED_DEBUG_LINE
     ElfW(Chdr) *chdr = (ElfW(Chdr) *)(file + shdr->sh_offset);
     unsigned long destsize = chdr->ch_size;
     int ret = 0;
 
     if (chdr->ch_type != ELFCOMPRESS_ZLIB) {
-	/* unsupported compression type */
-	return 0;
+        /* unsupported compression type */
+        return 0;
     }
 
     *ptr = malloc(destsize);
     if (!*ptr) return 0;
     ret = uncompress((Bytef *)*ptr, &destsize,
-	    (const Bytef*)chdr + sizeof(ElfW(Chdr)),
+            (const Bytef*)chdr + sizeof(ElfW(Chdr)),
             shdr->sh_size - sizeof(ElfW(Chdr)));
     if (ret != Z_OK) goto fail;
     return destsize;
 
 fail:
     free(*ptr);
+    *ptr = NULL;
 #endif
     return 0;
 }
@@ -1612,13 +2054,14 @@ fail:
 /* read file and fill lines */
 static uintptr_t
 fill_lines(int num_traces, void **traces, int check_debuglink,
-	   obj_info_t **objp, line_info_t *lines, int offset)
+           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
     int i, j;
     char *shstr;
     ElfW(Ehdr) *ehdr;
     ElfW(Shdr) *shdr, *shstr_shdr;
     ElfW(Shdr) *gnu_debuglink_shdr = NULL;
+    ElfW(Shdr) *note_gnu_build_id = NULL;
     int fd;
     off_t filesize;
     char *file;
@@ -1629,40 +2072,40 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
 
     fd = open(binary_filename, O_RDONLY);
     if (fd < 0) {
-	goto fail;
+        goto fail;
     }
     filesize = lseek(fd, 0, SEEK_END);
     if (filesize < 0) {
-	int e = errno;
-	close(fd);
-	kprintf("lseek: %s\n", strerror(e));
-	goto fail;
+        int e = errno;
+        close(fd);
+        kprintf("lseek: %s\n", strerror(e));
+        goto fail;
     }
 #if SIZEOF_OFF_T > SIZEOF_SIZE_T
     if (filesize > (off_t)SIZE_MAX) {
-	close(fd);
-	kprintf("Too large file %s\n", binary_filename);
-	goto fail;
+        close(fd);
+        kprintf("Too large file %s\n", binary_filename);
+        goto fail;
     }
 #endif
     lseek(fd, 0, SEEK_SET);
     /* async-signal unsafe */
     file = (char *)mmap(NULL, (size_t)filesize, PROT_READ, MAP_SHARED, fd, 0);
     if (file == MAP_FAILED) {
-	int e = errno;
-	close(fd);
-	kprintf("mmap: %s\n", strerror(e));
-	goto fail;
+        int e = errno;
+        close(fd);
+        kprintf("mmap: %s\n", strerror(e));
+        goto fail;
     }
     close(fd);
 
     ehdr = (ElfW(Ehdr) *)file;
     if (memcmp(ehdr->e_ident, "\177ELF", 4) != 0) {
-	/*
-	 * Huh? Maybe filename was overridden by setproctitle() and
-	 * it match non-elf file.
-	 */
-	goto fail;
+        /*
+         * Huh? Maybe filename was overridden by setproctitle() and
+         * it match non-elf file.
+         */
+        goto fail;
     }
     obj->mapped = file;
     obj->mapped_size = (size_t)filesize;
@@ -1674,34 +2117,43 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
 
     for (i = 0; i < ehdr->e_shnum; i++) {
         char *section_name = shstr + shdr[i].sh_name;
-	switch (shdr[i].sh_type) {
-	  case SHT_STRTAB:
-	    if (!strcmp(section_name, ".strtab")) {
-		strtab_shdr = shdr + i;
-	    }
-	    else if (!strcmp(section_name, ".dynstr")) {
-		dynstr_shdr = shdr + i;
-	    }
-	    break;
-	  case SHT_SYMTAB:
-	    /* if (!strcmp(section_name, ".symtab")) */
-	    symtab_shdr = shdr + i;
-	    break;
-	  case SHT_DYNSYM:
-	    /* if (!strcmp(section_name, ".dynsym")) */
-	    dynsym_shdr = shdr + i;
-	    break;
-	  case SHT_PROGBITS:
-	    if (!strcmp(section_name, ".gnu_debuglink")) {
-		gnu_debuglink_shdr = shdr + i;
-	    }
+        switch (shdr[i].sh_type) {
+          case SHT_STRTAB:
+            if (!strcmp(section_name, ".strtab")) {
+                strtab_shdr = shdr + i;
+            }
+            else if (!strcmp(section_name, ".dynstr")) {
+                dynstr_shdr = shdr + i;
+            }
+            break;
+          case SHT_SYMTAB:
+            /* if (!strcmp(section_name, ".symtab")) */
+            symtab_shdr = shdr + i;
+            break;
+          case SHT_DYNSYM:
+            /* if (!strcmp(section_name, ".dynsym")) */
+            dynsym_shdr = shdr + i;
+            break;
+          case SHT_NOTE:
+            if (!strcmp(section_name, ".note.gnu.build-id")) {
+                note_gnu_build_id = shdr + i;
+            }
+            break;
+          case SHT_PROGBITS:
+            if (!strcmp(section_name, ".gnu_debuglink")) {
+                gnu_debuglink_shdr = shdr + i;
+            }
             else {
                 const char *debug_section_names[] = {
                     ".debug_abbrev",
                     ".debug_info",
                     ".debug_line",
                     ".debug_ranges",
-                    ".debug_str"
+                    ".debug_str_offsets",
+                    ".debug_addr",
+                    ".debug_rnglists",
+                    ".debug_str",
+                    ".debug_line_str"
                 };
 
                 for (j=0; j < DWARF_SECTION_COUNT; j++) {
@@ -1720,17 +2172,16 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
                     break;
                 }
             }
-	    break;
-	}
+            break;
+        }
     }
 
-    if (offset == -1) {
-	/* main executable */
-	offset = 0;
-	if (dynsym_shdr && dynstr_shdr) {
-	    char *strtab = file + dynstr_shdr->sh_offset;
-	    ElfW(Sym) *symtab = (ElfW(Sym) *)(file + dynsym_shdr->sh_offset);
-	    int symtab_count = (int)(dynsym_shdr->sh_size / sizeof(ElfW(Sym)));
+    if (offset == 0) {
+        /* main executable */
+        if (dynsym_shdr && dynstr_shdr) {
+            char *strtab = file + dynstr_shdr->sh_offset;
+            ElfW(Sym) *symtab = (ElfW(Sym) *)(file + dynsym_shdr->sh_offset);
+            int symtab_count = (int)(dynsym_shdr->sh_size / sizeof(ElfW(Sym)));
             void *handle = dlopen(NULL, RTLD_NOW|RTLD_LOCAL);
             if (handle) {
                 for (j = 0; j < symtab_count; j++) {
@@ -1747,14 +2198,14 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
                 }
                 dlclose(handle);
             }
-	    if (ehdr->e_type == ET_EXEC) {
-		obj->base_addr = 0;
-	    }
-	    else {
-		/* PIE (position-independent executable) */
-		obj->base_addr = dladdr_fbase;
-	    }
-	}
+            if (ehdr->e_type == ET_EXEC) {
+                obj->base_addr = 0;
+            }
+            else {
+                /* PIE (position-independent executable) */
+                obj->base_addr = dladdr_fbase;
+            }
+        }
     }
 
     if (obj->debug_info.ptr && obj->debug_abbrev.ptr) {
@@ -1762,9 +2213,10 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
         debug_info_reader_init(&reader, obj);
         i = 0;
         while (reader.p < reader.pend) {
-            /* fprintf(stderr, "%d:%tx: CU[%d]\n", __LINE__, reader.p - reader.obj->debug_info.ptr, i++); */
-            if (di_read_cu(&reader)) goto use_symtab;
-            debug_info_read(&reader, num_traces, traces, lines, offset);
+            /* kprintf("%d:%tx: CU[%d]\n", __LINE__, reader.p - reader.obj->debug_info.ptr, i++); */
+            if (di_read_cu(&reader, errout)) goto use_symtab;
+            if (!debug_info_read(&reader, num_traces, traces, lines, offset, errout))
+                goto use_symtab;
         }
     }
     else {
@@ -1799,20 +2251,27 @@ use_symtab:
     }
 
     if (!obj->debug_line.ptr) {
-	/* This file doesn't have .debug_line section,
-	   let's check .gnu_debuglink section instead. */
-	if (gnu_debuglink_shdr && check_debuglink) {
-	    follow_debuglink(file + gnu_debuglink_shdr->sh_offset,
-			     num_traces, traces,
-			     objp, lines, offset);
-	}
-	goto finish;
+        /* This file doesn't have .debug_line section,
+           let's check .gnu_debuglink section instead. */
+        if (gnu_debuglink_shdr && check_debuglink) {
+            follow_debuglink(file + gnu_debuglink_shdr->sh_offset,
+                             num_traces, traces,
+                             objp, lines, offset, errout);
+        }
+        if (note_gnu_build_id && check_debuglink) {
+            ElfW(Nhdr) *nhdr = (ElfW(Nhdr)*) (file + note_gnu_build_id->sh_offset);
+            const char *build_id = (char *)(nhdr + 1) + nhdr->n_namesz;
+            follow_debuglink_build_id(build_id, nhdr->n_descsz,
+                               num_traces, traces,
+                               objp, lines, offset, errout);
+        }
+        goto finish;
     }
 
     if (parse_debug_line(num_traces, traces,
             obj->debug_line.ptr,
             obj->debug_line.size,
-            obj, lines, offset) == -1)
+            obj, lines, offset, errout) == -1)
         goto fail;
 
 finish:
@@ -1824,7 +2283,7 @@ fail:
 /* read file and fill lines */
 static uintptr_t
 fill_lines(int num_traces, void **traces, int check_debuglink,
-        obj_info_t **objp, line_info_t *lines, int offset)
+        obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
 # ifdef __LP64__
 #  define LP(x) x##_64
@@ -1903,13 +2362,13 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
         struct fat_header *fat = (struct fat_header *)file;
         char *q = file + sizeof(*fat);
         uint32_t nfat_arch = __builtin_bswap32(fat->nfat_arch);
-        /* fprintf(stderr,"%d: fat:%s %d\n",__LINE__, binary_filename,nfat_arch); */
+        /* kprintf("%d: fat:%s %d\n",__LINE__, binary_filename,nfat_arch); */
         for (uint32_t i = 0; i < nfat_arch; i++) {
             struct fat_arch *arch = (struct fat_arch *)q;
             cpu_type_t cputype = __builtin_bswap32(arch->cputype);
             cpu_subtype_t cpusubtype = __builtin_bswap32(arch->cpusubtype);
             uint32_t offset = __builtin_bswap32(arch->offset);
-            /* fprintf(stderr,"%d: fat %d %x/%x %x/%x\n",__LINE__, i, mhp->cputype,mhp->cpusubtype, cputype,cpusubtype); */
+            /* kprintf("%d: fat %d %x/%x %x/%x\n",__LINE__, i, mhp->cputype,mhp->cpusubtype, cputype,cpusubtype); */
             if (mhp->cputype == cputype &&
                     (cpu_subtype_t)(mhp->cpusubtype & ~CPU_SUBTYPE_MASK) == cpusubtype) {
                 p = file + offset;
@@ -1927,13 +2386,14 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
         goto fail;
     }
     else {
-        kprintf("'%s' is not a "
 # ifdef __LP64__
-                "64"
+#   define bitsize "64"
 # else
-                "32"
+#   define bitsize "32"
 # endif
+        kprintf("'%s' is not a " bitsize
                 "-bit Mach-O file!\n",binary_filename);
+# undef bitsize
         close(fd);
         goto fail;
     }
@@ -1950,7 +2410,11 @@ found_mach_header:
                     "__debug_info",
                     "__debug_line",
                     "__debug_ranges",
-                    "__debug_str"
+                    "__debug_str_offsets",
+                    "__debug_addr",
+                    "__debug_rnglists",
+                    "__debug_str",
+                    "__debug_line_str",
                 };
                 struct LP(segment_command) *scmd = (struct LP(segment_command) *)lcmd;
                 if (strcmp(scmd->segname, "__TEXT") == 0) {
@@ -1964,7 +2428,17 @@ found_mach_header:
                         for (int j=0; j < DWARF_SECTION_COUNT; j++) {
                             struct dwarf_section *s = obj_dwarf_section_at(obj, j);
 
-                            if (strcmp(sect->sectname, debug_section_names[j]) != 0)
+                            if (strcmp(sect->sectname, debug_section_names[j]) != 0
+#ifdef __APPLE__
+                                    /* macOS clang 16 generates DWARF5, which have Mach-O
+                                     * section names that are limited to 16 characters,
+                                     * which causes sections with long names to be truncated
+                                     * and not match above.
+                                     * See: https://wiki.dwarfstd.org/Best_Practices.md#Mach-2d-O
+                                     */
+                                    && strncmp(sect->sectname, debug_section_names[j], 16) != 0
+#endif
+                                )
                                 continue;
 
                             s->ptr = file + sect->offset;
@@ -1987,7 +2461,7 @@ found_mach_header:
                 char *strtab = file + cmd->stroff, *sname = 0;
                 uint32_t j;
                 uintptr_t saddr = 0;
-                /* kprintf("[%2d]: %x/symtab %p\n", i, cmd->cmd, p); */
+                /* kprintf("[%2d]: %x/symtab %p\n", i, cmd->cmd, (void *)p); */
                 for (j = 0; j < cmd->nsyms; j++) {
                     uintptr_t symsize, d;
                     struct LP(nlist) *e = &nl[j];
@@ -2021,15 +2495,16 @@ found_mach_header:
         DebugInfoReader reader;
         debug_info_reader_init(&reader, obj);
         while (reader.p < reader.pend) {
-            if (di_read_cu(&reader)) goto fail;
-            debug_info_read(&reader, num_traces, traces, lines, offset);
+            if (di_read_cu(&reader, errout)) goto fail;
+            if (!debug_info_read(&reader, num_traces, traces, lines, offset, errout))
+                goto fail;
         }
     }
 
     if (parse_debug_line(num_traces, traces,
             obj->debug_line.ptr,
             obj->debug_line.size,
-            obj, lines, offset) == -1)
+            obj, lines, offset, errout) == -1)
         goto fail;
 
     return dladdr_fbase;
@@ -2039,42 +2514,46 @@ fail:
 #endif
 
 #define HAVE_MAIN_EXE_PATH
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__DragonFly__)
 # include <sys/sysctl.h>
 #endif
-/* ssize_t main_exe_path(void)
+/* ssize_t main_exe_path(FILE *errout)
  *
  * store the path of the main executable to `binary_filename`,
  * and returns strlen(binary_filename).
  * it is NUL terminated.
  */
-#if defined(__linux__)
+#if defined(__linux__) || defined(__NetBSD__)
 static ssize_t
-main_exe_path(void)
+main_exe_path(FILE *errout)
 {
-# define PROC_SELF_EXE "/proc/self/exe"
+# if defined(__linux__)
+#  define PROC_SELF_EXE "/proc/self/exe"
+# elif defined(__NetBSD__)
+#  define PROC_SELF_EXE "/proc/curproc/exe"
+# endif
     ssize_t len = readlink(PROC_SELF_EXE, binary_filename, PATH_MAX);
     if (len < 0) return 0;
     binary_filename[len] = 0;
     return len;
 }
-#elif defined(__FreeBSD__)
+#elif defined(__FreeBSD__) || defined(__DragonFly__)
 static ssize_t
-main_exe_path(void)
+main_exe_path(FILE *errout)
 {
     int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
     size_t len = PATH_MAX;
     int err = sysctl(mib, 4, binary_filename, &len, NULL, 0);
     if (err) {
-	kprintf("Can't get the path of ruby");
-	return -1;
+        kprintf("Can't get the path of ruby");
+        return -1;
     }
     len--; /* sysctl sets strlen+1 */
     return len;
 }
 #elif defined(HAVE_LIBPROC_H)
 static ssize_t
-main_exe_path(void)
+main_exe_path(FILE *errout)
 {
     int len = proc_pidpath(getpid(), binary_filename, PATH_MAX);
     if (len == 0) return 0;
@@ -2086,7 +2565,7 @@ main_exe_path(void)
 #endif
 
 static void
-print_line0(line_info_t *line, void *address)
+print_line0(line_info_t *line, void *address, FILE *errout)
 {
     uintptr_t addr = (uintptr_t)address;
     uintptr_t d = addr - line->saddr;
@@ -2102,9 +2581,12 @@ print_line0(line_info_t *line, void *address)
     else if (!line->path) {
         kprintf("[0x%"PRIxPTR"]\n", addr);
     }
-    else if (!line->saddr || !line->sname) {
+    else if (!line->sname) {
         kprintf("%s(0x%"PRIxPTR") [0x%"PRIxPTR"]\n", line->path, addr-line->base_addr, addr);
     }
+    else if (!line->saddr) {
+        kprintf("%s(%s) [0x%"PRIxPTR"]\n", line->path, line->sname, addr);
+    }
     else if (line->line <= 0) {
         kprintf("%s(%s+0x%"PRIxPTR") [0x%"PRIxPTR"]\n", line->path, line->sname,
                 d, addr);
@@ -2124,16 +2606,16 @@ print_line0(line_info_t *line, void *address)
 }
 
 static void
-print_line(line_info_t *line, void *address)
+print_line(line_info_t *line, void *address, FILE *errout)
 {
-    print_line0(line, address);
+    print_line0(line, address, errout);
     if (line->next) {
-        print_line(line->next, NULL);
+        print_line(line->next, NULL, errout);
     }
 }
 
 void
-rb_dump_backtrace_with_lines(int num_traces, void **traces)
+rb_dump_backtrace_with_lines(int num_traces, void **traces, FILE *errout)
 {
     int i;
     /* async-signal unsafe */
@@ -2141,81 +2623,84 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces)
     obj_info_t *obj = NULL;
     /* 2 is NULL + main executable */
     void **dladdr_fbases = (void **)calloc(num_traces+2, sizeof(void *));
+
 #ifdef HAVE_MAIN_EXE_PATH
     char *main_path = NULL; /* used on printing backtrace */
     ssize_t len;
-    if ((len = main_exe_path()) > 0) {
-	main_path = (char *)alloca(len + 1);
-	if (main_path) {
-	    uintptr_t addr;
-	    memcpy(main_path, binary_filename, len+1);
-	    append_obj(&obj);
-	    obj->path = main_path;
-	    addr = fill_lines(num_traces, traces, 1, &obj, lines, -1);
-	    if (addr != (uintptr_t)-1) {
-		dladdr_fbases[0] = (void *)addr;
-	    }
-	}
+    if ((len = main_exe_path(errout)) > 0) {
+        main_path = (char *)alloca(len + 1);
+        if (main_path) {
+            uintptr_t addr;
+            memcpy(main_path, binary_filename, len+1);
+            append_obj(&obj);
+            obj->path = main_path;
+            addr = fill_lines(num_traces, traces, 1, &obj, lines, 0, errout);
+            if (addr != (uintptr_t)-1) {
+                dladdr_fbases[0] = (void *)addr;
+            }
+        }
     }
 #endif
 
     /* fill source lines by reading dwarf */
     for (i = 0; i < num_traces; i++) {
-	Dl_info info;
-	if (lines[i].line) continue;
-	if (dladdr(traces[i], &info)) {
-	    const char *path;
-	    void **p;
-
-	    /* skip symbols which is in already checked objects */
-	    /* if the binary is strip-ed, this may effect */
-	    for (p=dladdr_fbases; *p; p++) {
-		if (*p == info.dli_fbase) {
-		    lines[i].path = info.dli_fname;
-		    lines[i].sname = info.dli_sname;
-		    goto next_line;
-		}
-	    }
-	    *p = info.dli_fbase;
-
-	    append_obj(&obj);
-	    obj->base_addr = (uintptr_t)info.dli_fbase;
-	    path = info.dli_fname;
-	    obj->path = path;
-	    lines[i].path = path;
-            lines[i].sname = info.dli_sname;
-            lines[i].saddr = (uintptr_t)info.dli_saddr;
-	    strlcpy(binary_filename, path, PATH_MAX);
-	    if (fill_lines(num_traces, traces, 1, &obj, lines, i) == (uintptr_t)-1)
-		break;
-	}
+        Dl_info info;
+        if (lines[i].line) continue;
+        if (dladdr(traces[i], &info)) {
+            const char *path;
+            void **p;
+
+            /* skip symbols which is in already checked objects */
+            /* if the binary is strip-ed, this may effect */
+            for (p=dladdr_fbases; *p; p++) {
+                if (*p == info.dli_fbase) {
+                    if (info.dli_fname) lines[i].path = info.dli_fname;
+                    if (info.dli_sname) lines[i].sname = info.dli_sname;
+                    goto next_line;
+                }
+            }
+            *p = info.dli_fbase;
+
+            append_obj(&obj);
+            obj->base_addr = (uintptr_t)info.dli_fbase;
+            path = info.dli_fname;
+            obj->path = path;
+            if (path) lines[i].path = path;
+            if (info.dli_sname) {
+                lines[i].sname = info.dli_sname;
+                lines[i].saddr = (uintptr_t)info.dli_saddr;
+            }
+            strlcpy(binary_filename, path, PATH_MAX);
+            if (fill_lines(num_traces, traces, 1, &obj, lines, i, errout) == (uintptr_t)-1)
+                break;
+        }
 next_line:
-	continue;
+        continue;
     }
 
     /* output */
     for (i = 0; i < num_traces; i++) {
-        print_line(&lines[i], traces[i]);
+        print_line(&lines[i], traces[i], errout);
 
-	/* FreeBSD's backtrace may show _start and so on */
-	if (lines[i].sname && strcmp("main", lines[i].sname) == 0)
-	    break;
+        /* FreeBSD's backtrace may show _start and so on */
+        if (lines[i].sname && strcmp("main", lines[i].sname) == 0)
+            break;
     }
 
     /* free */
     while (obj) {
-	obj_info_t *o = obj;
+        obj_info_t *o = obj;
         for (i=0; i < DWARF_SECTION_COUNT; i++) {
             struct dwarf_section *s = obj_dwarf_section_at(obj, i);
             if (s->flags & SHF_COMPRESSED) {
                 free(s->ptr);
             }
         }
-	if (obj->mapped_size) {
-	    munmap(obj->mapped, obj->mapped_size);
-	}
-	obj = o->next;
-	free(o);
+        if (obj->mapped_size) {
+            munmap(obj->mapped, obj->mapped_size);
+        }
+        obj = o->next;
+        free(o);
     }
     for (i = 0; i < num_traces; i++) {
         line_info_t *line = lines[i].next;
@@ -2229,435 +2714,8 @@ next_line:
     free(dladdr_fbases);
 }
 
-/* From FreeBSD's lib/libstand/printf.c */
-/*-
- * Copyright (c) 1986, 1988, 1991, 1993
- *	The Regents of the University of California.  All rights reserved.
- * (c) UNIX System Laboratories, Inc.
- * All or some portions of this file are derived from material licensed
- * to the University of California by American Telephone and Telegraph
- * Co. or Unix System Laboratories, Inc. and are reproduced herein with
- * the permission of UNIX System Laboratories, Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
- */
-
-#include <stdarg.h>
-#define MAXNBUF (sizeof(intmax_t) * CHAR_BIT + 1)
-static inline int toupper(int c) { return ('A' <= c && c <= 'Z') ? (c&0x5f) : c; }
-#define    hex2ascii(hex)  (hex2ascii_data[hex])
-static const char hex2ascii_data[] = "0123456789abcdefghijklmnopqrstuvwxyz";
-static inline int imax(int a, int b) { return (a > b ? a : b); }
-static int kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap);
+#undef kprintf
 
-static void putce(int c)
-{
-    char s[1];
-    ssize_t ret;
-
-    s[0] = (char)c;
-    ret = write(2, s, 1);
-    (void)ret;
-}
-
-static int
-kprintf(const char *fmt, ...)
-{
-	va_list ap;
-	int retval;
-
-	va_start(ap, fmt);
-	retval = kvprintf(fmt, putce, NULL, 10, ap);
-	va_end(ap);
-	return retval;
-}
-
-/*
- * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
- * order; return an optional length and a pointer to the last character
- * written in the buffer (i.e., the first character of the string).
- * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
- */
-static char *
-ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
-{
-	char *p, c;
-
-	p = nbuf;
-	*p = '\0';
-	do {
-		c = hex2ascii(num % base);
-		*++p = upper ? toupper(c) : c;
-	} while (num /= base);
-	if (lenp)
-		*lenp = (int)(p - nbuf);
-	return (p);
-}
-
-/*
- * Scaled down version of printf(3).
- *
- * Two additional formats:
- *
- * The format %b is supported to decode error registers.
- * Its usage is:
- *
- *	printf("reg=%b\n", regval, "<base><arg>*");
- *
- * where <base> is the output base expressed as a control character, e.g.
- * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
- * the first of which gives the bit number to be inspected (origin 1), and
- * the next characters (up to a control character, i.e. a character <= 32),
- * give the name of the register.  Thus:
- *
- *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
- *
- * would produce output:
- *
- *	reg=3<BITTWO,BITONE>
- *
- * XXX:  %D  -- Hexdump, takes pointer and separator string:
- *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
- *		("%*D", len, ptr, " " -> XX XX XX XX ...
- */
-static int
-kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap)
-{
-#define PCHAR(c) {int cc=(c); if (func) (*func)(cc); else *d++ = cc; retval++; }
-	char nbuf[MAXNBUF];
-	char *d;
-	const char *p, *percent, *q;
-	unsigned char *up;
-	int ch, n;
-	uintmax_t num;
-	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
-	int cflag, hflag, jflag, tflag, zflag;
-	int dwidth, upper;
-	char padc;
-	int stop = 0, retval = 0;
-
-	num = 0;
-	if (!func)
-		d = (char *) arg;
-	else
-		d = NULL;
-
-	if (fmt == NULL)
-		fmt = "(fmt null)\n";
-
-	if (radix < 2 || radix > 36)
-		radix = 10;
-
-	for (;;) {
-		padc = ' ';
-		width = 0;
-		while ((ch = (unsigned char)*fmt++) != '%' || stop) {
-			if (ch == '\0')
-				return (retval);
-			PCHAR(ch);
-		}
-		percent = fmt - 1;
-		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
-		sign = 0; dot = 0; dwidth = 0; upper = 0;
-		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
-reswitch:	switch (ch = (unsigned char)*fmt++) {
-		case '.':
-			dot = 1;
-			goto reswitch;
-		case '#':
-			sharpflag = 1;
-			goto reswitch;
-		case '+':
-			sign = 1;
-			goto reswitch;
-		case '-':
-			ladjust = 1;
-			goto reswitch;
-		case '%':
-			PCHAR(ch);
-			break;
-		case '*':
-			if (!dot) {
-				width = va_arg(ap, int);
-				if (width < 0) {
-					ladjust = !ladjust;
-					width = -width;
-				}
-			} else {
-				dwidth = va_arg(ap, int);
-			}
-			goto reswitch;
-		case '0':
-			if (!dot) {
-				padc = '0';
-				goto reswitch;
-			}
-		case '1': case '2': case '3': case '4':
-		case '5': case '6': case '7': case '8': case '9':
-				for (n = 0;; ++fmt) {
-					n = n * 10 + ch - '0';
-					ch = *fmt;
-					if (ch < '0' || ch > '9')
-						break;
-				}
-			if (dot)
-				dwidth = n;
-			else
-				width = n;
-			goto reswitch;
-		case 'b':
-			num = (unsigned int)va_arg(ap, int);
-			p = va_arg(ap, char *);
-			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
-				PCHAR(*q--);
-
-			if (num == 0)
-				break;
-
-			for (tmp = 0; *p;) {
-				n = *p++;
-				if (num & (1 << (n - 1))) {
-					PCHAR(tmp ? ',' : '<');
-					for (; (n = *p) > ' '; ++p)
-						PCHAR(n);
-					tmp = 1;
-				} else
-					for (; *p > ' '; ++p)
-						continue;
-			}
-			if (tmp)
-				PCHAR('>');
-			break;
-		case 'c':
-			PCHAR(va_arg(ap, int));
-			break;
-		case 'D':
-			up = va_arg(ap, unsigned char *);
-			p = va_arg(ap, char *);
-			if (!width)
-				width = 16;
-			while(width--) {
-				PCHAR(hex2ascii(*up >> 4));
-				PCHAR(hex2ascii(*up & 0x0f));
-				up++;
-				if (width)
-					for (q=p;*q;q++)
-						PCHAR(*q);
-			}
-			break;
-		case 'd':
-		case 'i':
-			base = 10;
-			sign = 1;
-			goto handle_sign;
-		case 'h':
-			if (hflag) {
-				hflag = 0;
-				cflag = 1;
-			} else
-				hflag = 1;
-			goto reswitch;
-		case 'j':
-			jflag = 1;
-			goto reswitch;
-		case 'l':
-			if (lflag) {
-				lflag = 0;
-				qflag = 1;
-			} else
-				lflag = 1;
-			goto reswitch;
-		case 'n':
-			if (jflag)
-				*(va_arg(ap, intmax_t *)) = retval;
-			else if (qflag)
-				*(va_arg(ap, int64_t *)) = retval;
-			else if (lflag)
-				*(va_arg(ap, long *)) = retval;
-			else if (zflag)
-				*(va_arg(ap, size_t *)) = retval;
-			else if (hflag)
-				*(va_arg(ap, short *)) = retval;
-			else if (cflag)
-				*(va_arg(ap, char *)) = retval;
-			else
-				*(va_arg(ap, int *)) = retval;
-			break;
-		case 'o':
-			base = 8;
-			goto handle_nosign;
-		case 'p':
-			base = 16;
-			sharpflag = (width == 0);
-			sign = 0;
-			num = (uintptr_t)va_arg(ap, void *);
-			goto number;
-		case 'q':
-			qflag = 1;
-			goto reswitch;
-		case 'r':
-			base = radix;
-			if (sign)
-				goto handle_sign;
-			goto handle_nosign;
-		case 's':
-			p = va_arg(ap, char *);
-			if (p == NULL)
-				p = "(null)";
-			if (!dot)
-				n = (int)strlen (p);
-			else
-				for (n = 0; n < dwidth && p[n]; n++)
-					continue;
-
-			width -= n;
-
-			if (!ladjust && width > 0)
-				while (width--)
-					PCHAR(padc);
-			while (n--)
-				PCHAR(*p++);
-			if (ladjust && width > 0)
-				while (width--)
-					PCHAR(padc);
-			break;
-		case 't':
-			tflag = 1;
-			goto reswitch;
-		case 'u':
-			base = 10;
-			goto handle_nosign;
-		case 'X':
-			upper = 1;
-		case 'x':
-			base = 16;
-			goto handle_nosign;
-		case 'y':
-			base = 16;
-			sign = 1;
-			goto handle_sign;
-		case 'z':
-			zflag = 1;
-			goto reswitch;
-handle_nosign:
-			sign = 0;
-			if (jflag)
-				num = va_arg(ap, uintmax_t);
-			else if (qflag)
-				num = va_arg(ap, uint64_t);
-			else if (tflag)
-				num = va_arg(ap, ptrdiff_t);
-			else if (lflag)
-				num = va_arg(ap, unsigned long);
-			else if (zflag)
-				num = va_arg(ap, size_t);
-			else if (hflag)
-				num = (unsigned short)va_arg(ap, int);
-			else if (cflag)
-				num = (unsigned char)va_arg(ap, int);
-			else
-				num = va_arg(ap, unsigned int);
-			goto number;
-handle_sign:
-			if (jflag)
-				num = va_arg(ap, intmax_t);
-			else if (qflag)
-				num = va_arg(ap, int64_t);
-			else if (tflag)
-				num = va_arg(ap, ptrdiff_t);
-			else if (lflag)
-				num = va_arg(ap, long);
-			else if (zflag)
-				num = va_arg(ap, ssize_t);
-			else if (hflag)
-				num = (short)va_arg(ap, int);
-			else if (cflag)
-				num = (char)va_arg(ap, int);
-			else
-				num = va_arg(ap, int);
-number:
-			if (sign && (intmax_t)num < 0) {
-				neg = 1;
-				num = -(intmax_t)num;
-			}
-			p = ksprintn(nbuf, num, base, &n, upper);
-			tmp = 0;
-			if (sharpflag && num != 0) {
-				if (base == 8)
-					tmp++;
-				else if (base == 16)
-					tmp += 2;
-			}
-			if (neg)
-				tmp++;
-
-			if (!ladjust && padc == '0')
-				dwidth = width - tmp;
-			width -= tmp + imax(dwidth, n);
-			dwidth -= n;
-			if (!ladjust)
-				while (width-- > 0)
-					PCHAR(' ');
-			if (neg)
-				PCHAR('-');
-			if (sharpflag && num != 0) {
-				if (base == 8) {
-					PCHAR('0');
-				} else if (base == 16) {
-					PCHAR('0');
-					PCHAR('x');
-				}
-			}
-			while (dwidth-- > 0)
-				PCHAR('0');
-
-			while (*p)
-				PCHAR(*p--);
-
-			if (ladjust)
-				while (width-- > 0)
-					PCHAR(' ');
-
-			break;
-		default:
-			while (percent < fmt)
-				PCHAR(*percent++);
-			/*
-			 * Since we ignore an formatting argument it is no
-			 * longer safe to obey the remaining formatting
-			 * arguments as the arguments will no longer match
-			 * the format specs.
-			 */
-			stop = 1;
-			break;
-		}
-	}
-#undef PCHAR
-}
 #else /* defined(USE_ELF) */
 #error not supported
 #endif
diff --git a/addr2line.h b/addr2line.h
index 4f6cf179ef..ff8e476b92 100644
--- a/addr2line.h
+++ b/addr2line.h
@@ -1,3 +1,5 @@
+#ifndef RUBY_ADDR2LINE_H
+#define RUBY_ADDR2LINE_H
 /**********************************************************************
 
   addr2line.h -
@@ -8,13 +10,12 @@
 
 **********************************************************************/
 
-#ifndef RUBY_ADDR2LINE_H
-#define RUBY_ADDR2LINE_H
-
 #if (defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H))
 
+#include <stdio.h>
+
 void
-rb_dump_backtrace_with_lines(int num_traces, void **traces);
+rb_dump_backtrace_with_lines(int num_traces, void **traces, FILE *errout);
 
 #endif /* USE_ELF */
 
diff --git a/appveyor.yml b/appveyor.yml
deleted file mode 100644
index 28ca917e8e..0000000000
--- a/appveyor.yml
+++ /dev/null
@@ -1,143 +0,0 @@
----
-version: '{build}'
-shallow_clone: true
-platform:
-  - x64
-branches:
-  except:
-    - trunk # mirrored from trunk. avoid doubly building on it
-environment:
-  ruby_version: "24-%Platform%"
-  zlib_version: "1.2.11"
-  matrix:
-    # to reduce time for finishing all jobs, run the slowest msys2 build first.
-    - build: msys2
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-    - build: vs
-      vs: 120
-      ssl: OpenSSL
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
-    - build: vs
-      vs: 140
-      ssl: OpenSSL-v111
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-  RELINE_TEST_ENCODING: "Windows-31J"
-  GEMS_FOR_TEST: "timezone tzinfo"
-  UPDATE_UNICODE: "UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
-for:
--
-  matrix:
-    only:
-      - build: vs
-  install:
-    - ver
-    - chcp
-    - SET BITS=%Platform:x86=32%
-    - SET BITS=%BITS:x=%
-    - SET OPENSSL_DIR=C:\%ssl%-Win%BITS%
-    - CALL SET vcvars=%%^VS%VS%COMNTOOLS^%%..\..\VC\vcvarsall.bat
-    - SET vcvars
-    - '"%vcvars%" %Platform:x64=amd64%'
-    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
-    - SET PATH=\usr\local\bin;%ruby_path%\bin;%PATH%;C:\msys64\mingw64\bin;C:\msys64\usr\bin
-    - ruby --version
-    - 'cl'
-    - echo> Makefile srcdir=.
-    - echo>> Makefile MSC_VER=0
-    - echo>> Makefile RT=none
-    - echo>> Makefile RT_VER=0
-    - echo>> Makefile BUILTIN_ENCOBJS=nul
-    - type win32\Makefile.sub >> Makefile
-    - nmake %mflags% touch-unicode-files
-    - nmake %mflags% %UPDATE_UNICODE% up incs
-    - del Makefile
-    - mkdir \usr\local\bin
-    - mkdir \usr\local\include
-    - mkdir \usr\local\lib
-    - curl -fsSL -o zlib%zlib_version:.=%.zip --retry 10 https://zlib.net/zlib%zlib_version:.=%.zip
-    - 7z x -o%APPVEYOR_BUILD_FOLDER%\ext\zlib zlib%zlib_version:.=%.zip
-    - for %%I in (%OPENSSL_DIR%\*.dll) do mklink /h \usr\local\bin\%%~nxI %%I
-    - attrib +r /s /d
-    - mkdir %Platform%-mswin_%vs%
-  build_script:
-    - cd %APPVEYOR_BUILD_FOLDER%
-    - cd %Platform%-mswin_%vs%
-    - ..\win32\configure.bat --without-ext=+,dbm,gdbm,readline --with-opt-dir=/usr/local --with-openssl-dir=%OPENSSL_DIR:\=/%
-    - nmake -l
-    - nmake install-nodoc
-    - \usr\bin\ruby -v -e "p :locale => Encoding.find('locale'), :filesystem => Encoding.find('filesystem')"
-    - if not "%GEMS_FOR_TEST%" == "" \usr\bin\gem install --no-document %GEMS_FOR_TEST%
-    - \usr\bin\ruby -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
-  test_script:
-    - set /a JOBS=%NUMBER_OF_PROCESSORS%
-    - nmake -l "TESTOPTS=-v -q" btest
-    - nmake -l "TESTOPTS=-v -q" test-basic
-    - nmake -l "TESTOPTS=-v --timeout-scale=3.0 --excludes=../test/excludes/_appveyor -j%JOBS% --exclude readline --exclude win32ole --exclude test_bignum --exclude test_syntax --exclude test_open-uri --exclude test_bundled_ca" test-all
-    # separately execute tests without -j which may crash worker with -j.
-    - nmake -l "TESTOPTS=-v --timeout-scale=3.0 --excludes=../test/excludes/_appveyor" test-all TESTS="../test/win32ole ../test/ruby/test_bignum.rb ../test/ruby/test_syntax.rb ../test/open-uri/test_open-uri.rb ../test/rubygems/test_bundled_ca.rb"
-    - nmake -l test-spec MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
--
-  matrix:
-    only:
-      - build: msys2
-  install:
-    - ver
-    - chcp
-    - set /a JOBS=%NUMBER_OF_PROCESSORS%
-    - set MSYS_NO_PATHCONV=1
-    - SET MSYSTEM=%Platform:x86=32%
-    - SET MSYSTEM=%MSYSTEM:x=MINGW%
-    - SET MSYS2_ARCH=%Platform:x86=i686%
-    - SET MSYS2_ARCH=%MSYS2_ARCH:x64=x86_64%
-    - set MSYSTEM_PREFIX=/mingw64
-    - set MINGW_CHOST=%MSYS2_ARCH%-w64-mingw32
-    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
-    - cd ..
-    - mkdir build
-    - mkdir install
-    - SET PATH=%ruby_path%\bin;C:\msys64\%MSYSTEM%\bin;C:\msys64\usr\bin;%PATH%
-    - ruby --version
-  build_script:
-    - pacman -Sy --noconfirm --noprogressbar --needed mingw-w64-x86_64-toolchain
-    - pacman -S  --noconfirm --noprogressbar --needed mingw-w64-x86_64-gdbm mingw-w64-x86_64-gmp mingw-w64-x86_64-libffi mingw-w64-x86_64-libyaml mingw-w64-x86_64-openssl mingw-w64-x86_64-ragel mingw-w64-x86_64-readline mingw-w64-x86_64-zlib
-    - cd %APPVEYOR_BUILD_FOLDER%
-    - set CFLAGS=-march=%MSYS2_ARCH:_=-% -mtune=generic -O3 -pipe
-    - set CXXFLAGS=%CFLAGS%
-    - set CPPFLAGS=-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048
-    - set LDFLAGS=-pipe
-    - sh -c "autoreconf -fi"
-    - cd ..\build
-    - sh ../ruby/configure --disable-install-doc --prefix=/. --build=%MINGW_CHOST% --host=%MINGW_CHOST% --target=%MINGW_CHOST%
-    - mingw32-make %mflags% touch-unicode-files
-    - mingw32-make -j%JOBS% %UPDATE_UNICODE% up incs
-    - mingw32-make -j%JOBS% V=1
-    - mingw32-make DESTDIR=../install install-nodoc
-    - if not "%GEMS_FOR_TEST%" == "" ..\install\bin\gem install --no-document %GEMS_FOR_TEST%
-    - ..\install\bin\ruby.exe -v -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
-  test_script:
-    - mingw32-make test
-    - mingw32-make test-all TESTOPTS="--retry --job-status=normal --show-skip --timeout-scale=1.5 --excludes=../ruby/test/excludes/_appveyor -j %JOBS% --exclude win32ole --exclude test_open-uri"
-    # separately execute tests without -j which may crash worker with -j.
-    - mingw32-make test-all TESTOPTS="--retry --job-status=normal --show-skip --timeout-scale=1.5 --excludes=../ruby/test/excludes/_appveyor" TESTS="../ruby/test/win32ole ../ruby/test/open-uri/test_open-uri.rb"
-    - mingw32-make test-spec MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
-notifications:
-  # Using "Webhook" with templated body to skip notification on Pull Request
-  - provider: Webhook
-    method: POST
-    url:
-      secure: iMINHMS0nZabaDsxN9omRDsekxzVvAAzEq5ev7lN6vb+gUETT+rbDKLGxBxBpEpxlnPlLdzroIJ+DTKlwfJA8VkGawTn9EXNsucH0OkSf2M= # AppVeyor CI
-    body: >-
-      {{^isPullRequest}}
-        {
-          "attachments": [
-            {
-              "text": "Build <{{buildUrl}}|#{{buildVersion}}> (<{{commitUrl}}|{{commitId}}>) of {{repositoryName}}@{{branch}} by {{commitAuthor}} {{status}}",
-              "color": "{{#passed}}good{{/passed}}{{#failed}}danger{{/failed}}"
-            }
-          ],
-          "channel": "#alerts"
-        }
-      {{/isPullRequest}}
-    on_build_success: false
-    on_build_failure: true
-    on_build_status_changed: true
diff --git a/array.c b/array.c
index c63bfb3b93..db4c2c4802 100644
--- a/array.c
+++ b/array.c
@@ -10,21 +10,62 @@
   Copyright (C) 2000  Information-technology Promotion Agency, Japan
 
 **********************************************************************/
-#include "ruby/encoding.h"
-#include "ruby/util.h"
-#include "ruby/st.h"
-#include "probes.h"
-#include "id.h"
+
 #include "debug_counter.h"
-#include "transient_heap.h"
+#include "id.h"
 #include "internal.h"
+#include "internal/array.h"
+#include "internal/compar.h"
+#include "internal/enum.h"
+#include "internal/gc.h"
+#include "internal/hash.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/proc.h"
+#include "internal/rational.h"
+#include "internal/vm.h"
+#include "probes.h"
+#include "ruby/encoding.h"
+#include "ruby/st.h"
+#include "ruby/thread.h"
+#include "ruby/util.h"
+#include "ruby/ractor.h"
+#include "shape.h"
+#include "vm_core.h"
+#include "builtin.h"
 
 #if !ARRAY_DEBUG
+# undef NDEBUG
 # define NDEBUG
 #endif
 #include "ruby_assert.h"
 
 VALUE rb_cArray;
+VALUE rb_cArray_empty_frozen;
+
+/* Flags of RArray
+ *
+ * 0:   RARRAY_SHARED_FLAG (equal to ELTS_SHARED)
+ *          The array is shared. The buffer this array points to is owned by
+ *          another array (the shared root).
+ * 1:   RARRAY_EMBED_FLAG
+ *          The array is embedded (its contents follow the header, rather than
+ *          being on a separately allocated buffer).
+ * 3-9: RARRAY_EMBED_LEN
+ *          The length of the array when RARRAY_EMBED_FLAG is set.
+ * 12:  RARRAY_SHARED_ROOT_FLAG
+ *          The array is a shared root that does reference counting. The buffer
+ *          this array points to is owned by this array but may be pointed to
+ *          by other arrays.
+ *          Note: Frozen arrays may be a shared root without this flag being
+ *                set. Frozen arrays do not have reference counting because
+ *                they cannot be modified. Not updating the reference count
+ *                improves copy-on-write performance. Their reference count is
+ *                assumed to be infinity.
+ * 14:  RARRAY_PTR_IN_USE_FLAG
+ *          The buffer of the array is in use. This is only used during
+ *          debugging.
+ */
 
 /* for OPTIMIZED_CMP: */
 #define id_cmp idCmp
@@ -33,71 +74,56 @@ VALUE rb_cArray;
 #define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))
 #define SMALL_ARRAY_LEN 16
 
+RBIMPL_ATTR_MAYBE_UNUSED()
 static int
 should_be_T_ARRAY(VALUE ary)
 {
     return RB_TYPE_P(ary, T_ARRAY);
 }
 
-static int
-should_not_be_shared_and_embedded(VALUE ary)
-{
-    return !FL_TEST((ary), ELTS_SHARED) || !FL_TEST((ary), RARRAY_EMBED_FLAG);
-}
-
-#define ARY_SHARED_P(ary) \
-  (assert(should_be_T_ARRAY((VALUE)(ary))), \
-   assert(should_not_be_shared_and_embedded((VALUE)ary)), \
-   FL_TEST_RAW((ary),ELTS_SHARED)!=0)
-
-#define ARY_EMBED_P(ary) \
-  (assert(should_be_T_ARRAY((VALUE)(ary))), \
-   assert(should_not_be_shared_and_embedded((VALUE)ary)), \
-   FL_TEST_RAW((ary), RARRAY_EMBED_FLAG) != 0)
-
-#define ARY_HEAP_PTR(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.ptr)
-#define ARY_HEAP_LEN(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.len)
-#define ARY_HEAP_CAPA(a) (assert(!ARY_EMBED_P(a)), assert(!ARY_SHARED_ROOT_P(a)), \
+#define ARY_HEAP_PTR(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.ptr)
+#define ARY_HEAP_LEN(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.len)
+#define ARY_HEAP_CAPA(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RUBY_ASSERT(!ARY_SHARED_ROOT_P(a)), \
                           RARRAY(a)->as.heap.aux.capa)
 
-#define ARY_EMBED_PTR(a) (assert(ARY_EMBED_P(a)), RARRAY(a)->as.ary)
+#define ARY_EMBED_PTR(a) (RUBY_ASSERT(ARY_EMBED_P(a)), RARRAY(a)->as.ary)
 #define ARY_EMBED_LEN(a) \
-    (assert(ARY_EMBED_P(a)), \
+    (RUBY_ASSERT(ARY_EMBED_P(a)), \
      (long)((RBASIC(a)->flags >> RARRAY_EMBED_LEN_SHIFT) & \
-	 (RARRAY_EMBED_LEN_MASK >> RARRAY_EMBED_LEN_SHIFT)))
-#define ARY_HEAP_SIZE(a) (assert(!ARY_EMBED_P(a)), assert(ARY_OWNS_HEAP_P(a)), ARY_CAPA(a) * sizeof(VALUE))
+         (RARRAY_EMBED_LEN_MASK >> RARRAY_EMBED_LEN_SHIFT)))
+#define ARY_HEAP_SIZE(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RUBY_ASSERT(ARY_OWNS_HEAP_P(a)), ARY_CAPA(a) * sizeof(VALUE))
 
-#define ARY_OWNS_HEAP_P(a) (assert(should_be_T_ARRAY((VALUE)(a))), \
-                            !FL_TEST_RAW((a), ELTS_SHARED|RARRAY_EMBED_FLAG))
+#define ARY_OWNS_HEAP_P(a) (RUBY_ASSERT(should_be_T_ARRAY((VALUE)(a))), \
+                            !FL_TEST_RAW((a), RARRAY_SHARED_FLAG|RARRAY_EMBED_FLAG))
 
 #define FL_SET_EMBED(a) do { \
-    assert(!ARY_SHARED_P(a)); \
+    RUBY_ASSERT(!ARY_SHARED_P(a)); \
     FL_SET((a), RARRAY_EMBED_FLAG); \
-    RARY_TRANSIENT_UNSET(a); \
     ary_verify(a); \
 } while (0)
 
 #define FL_UNSET_EMBED(ary) FL_UNSET((ary), RARRAY_EMBED_FLAG|RARRAY_EMBED_LEN_MASK)
 #define FL_SET_SHARED(ary) do { \
-    assert(!ARY_EMBED_P(ary)); \
-    FL_SET((ary), ELTS_SHARED); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    FL_SET((ary), RARRAY_SHARED_FLAG); \
 } while (0)
-#define FL_UNSET_SHARED(ary) FL_UNSET((ary), ELTS_SHARED)
+#define FL_UNSET_SHARED(ary) FL_UNSET((ary), RARRAY_SHARED_FLAG)
 
+#define ARY_SET_PTR_FORCE(ary, p) \
+    (RARRAY(ary)->as.heap.ptr = (p))
 #define ARY_SET_PTR(ary, p) do { \
-    assert(!ARY_EMBED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
-    RARRAY(ary)->as.heap.ptr = (p); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    ARY_SET_PTR_FORCE(ary, p); \
 } while (0)
 #define ARY_SET_EMBED_LEN(ary, n) do { \
     long tmp_n = (n); \
-    assert(ARY_EMBED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(ARY_EMBED_P(ary)); \
     RBASIC(ary)->flags &= ~RARRAY_EMBED_LEN_MASK; \
     RBASIC(ary)->flags |= (tmp_n) << RARRAY_EMBED_LEN_SHIFT; \
 } while (0)
 #define ARY_SET_HEAP_LEN(ary, n) do { \
-    assert(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
     RARRAY(ary)->as.heap.len = (n); \
 } while (0)
 #define ARY_SET_LEN(ary, n) do { \
@@ -107,15 +133,15 @@ should_not_be_shared_and_embedded(VALUE ary)
     else { \
         ARY_SET_HEAP_LEN((ary), (n)); \
     } \
-    assert(RARRAY_LEN(ary) == (n)); \
+    RUBY_ASSERT(RARRAY_LEN(ary) == (n)); \
 } while (0)
 #define ARY_INCREASE_PTR(ary, n) do  { \
-    assert(!ARY_EMBED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
     RARRAY(ary)->as.heap.ptr += (n); \
 } while (0)
 #define ARY_INCREASE_LEN(ary, n) do  { \
-    assert(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
     if (ARY_EMBED_P(ary)) { \
         ARY_SET_EMBED_LEN((ary), RARRAY_LEN(ary)+(n)); \
     } \
@@ -124,50 +150,93 @@ should_not_be_shared_and_embedded(VALUE ary)
     } \
 } while (0)
 
-#define ARY_CAPA(ary) (ARY_EMBED_P(ary) ? RARRAY_EMBED_LEN_MAX : \
+#define ARY_CAPA(ary) (ARY_EMBED_P(ary) ? ary_embed_capa(ary) : \
                        ARY_SHARED_ROOT_P(ary) ? RARRAY_LEN(ary) : ARY_HEAP_CAPA(ary))
+#define ARY_SET_CAPA_FORCE(ary, n) \
+    RARRAY(ary)->as.heap.aux.capa = (n);
 #define ARY_SET_CAPA(ary, n) do { \
-    assert(!ARY_EMBED_P(ary)); \
-    assert(!ARY_SHARED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
-    RARRAY(ary)->as.heap.aux.capa = (n); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!ARY_SHARED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    ARY_SET_CAPA_FORCE(ary, n); \
 } while (0)
 
-#define ARY_SHARED_ROOT(ary) (assert(ARY_SHARED_P(ary)), RARRAY(ary)->as.heap.aux.shared_root)
-#define ARY_SET_SHARED(ary, value) do { \
-    const VALUE _ary_ = (ary); \
-    const VALUE _value_ = (value); \
-    assert(!ARY_EMBED_P(_ary_)); \
-    assert(ARY_SHARED_P(_ary_)); \
-    assert(ARY_SHARED_ROOT_P(_value_)); \
-    RB_OBJ_WRITE(_ary_, &RARRAY(_ary_)->as.heap.aux.shared_root, _value_); \
-} while (0)
-#define RARRAY_SHARED_ROOT_FLAG FL_USER5
-#define ARY_SHARED_ROOT_P(ary) (assert(should_be_T_ARRAY((VALUE)(ary))), \
-                                FL_TEST_RAW((ary), RARRAY_SHARED_ROOT_FLAG))
-#define ARY_SHARED_ROOT_REFCNT(ary) \
-    (assert(ARY_SHARED_ROOT_P(ary)), RARRAY(ary)->as.heap.aux.capa)
-#define ARY_SHARED_ROOT_OCCUPIED(ary) (ARY_SHARED_ROOT_REFCNT(ary) == 1)
+#define ARY_SHARED_ROOT_OCCUPIED(ary) (!OBJ_FROZEN(ary) && ARY_SHARED_ROOT_REFCNT(ary) == 1)
 #define ARY_SET_SHARED_ROOT_REFCNT(ary, value) do { \
-    assert(ARY_SHARED_ROOT_P(ary)); \
+    RUBY_ASSERT(ARY_SHARED_ROOT_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT((value) >= 0); \
     RARRAY(ary)->as.heap.aux.capa = (value); \
 } while (0)
 #define FL_SET_SHARED_ROOT(ary) do { \
-    assert(!ARY_EMBED_P(ary)); \
-    assert(!RARRAY_TRANSIENT_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
     FL_SET((ary), RARRAY_SHARED_ROOT_FLAG); \
 } while (0)
 
 static inline void
 ARY_SET(VALUE a, long i, VALUE v)
 {
-    assert(!ARY_SHARED_P(a));
-    assert(!OBJ_FROZEN(a));
+    RUBY_ASSERT(!ARY_SHARED_P(a));
+    RUBY_ASSERT(!OBJ_FROZEN(a));
 
     RARRAY_ASET(a, i, v);
 }
 #undef RARRAY_ASET
 
+static long
+ary_embed_capa(VALUE ary)
+{
+    size_t size = rb_gc_obj_slot_size(ary) - offsetof(struct RArray, as.ary);
+    RUBY_ASSERT(size % sizeof(VALUE) == 0);
+    return size / sizeof(VALUE);
+}
+
+static size_t
+ary_embed_size(long capa)
+{
+    size_t size = offsetof(struct RArray, as.ary) + (sizeof(VALUE) * capa);
+    if (size < sizeof(struct RArray)) size = sizeof(struct RArray);
+    return size;
+}
+
+static bool
+ary_embeddable_p(long capa)
+{
+    return rb_gc_size_allocatable_p(ary_embed_size(capa));
+}
+
+bool
+rb_ary_embeddable_p(VALUE ary)
+{
+    /* An array cannot be turned embeddable when the array is:
+     *  - Shared root: other objects may point to the buffer of this array
+     *    so we cannot make it embedded.
+     *  - Frozen: this array may also be a shared root without the shared root
+     *    flag.
+     *  - Shared: we don't want to re-embed an array that points to a shared
+     *    root (to save memory).
+     */
+    return !(ARY_SHARED_ROOT_P(ary) || OBJ_FROZEN(ary) || ARY_SHARED_P(ary));
+}
+
+size_t
+rb_ary_size_as_embedded(VALUE ary)
+{
+    size_t real_size;
+
+    if (ARY_EMBED_P(ary)) {
+        real_size = ary_embed_size(ARY_EMBED_LEN(ary));
+    }
+    else if (rb_ary_embeddable_p(ary)) {
+        real_size = ary_embed_size(ARY_HEAP_CAPA(ary));
+    }
+    else {
+        real_size = sizeof(struct RArray);
+    }
+    return real_size;
+}
+
 
 #if ARRAY_DEBUG
 #define ary_verify(ary) ary_verify_(ary, __FILE__, __LINE__)
@@ -175,25 +244,23 @@ ARY_SET(VALUE a, long i, VALUE v)
 static VALUE
 ary_verify_(VALUE ary, const char *file, int line)
 {
-    assert(RB_TYPE_P(ary, T_ARRAY));
+    RUBY_ASSERT(RB_TYPE_P(ary, T_ARRAY));
 
-    if (FL_TEST(ary, ELTS_SHARED)) {
-        VALUE root = RARRAY(ary)->as.heap.aux.shared_root;
+    if (ARY_SHARED_P(ary)) {
+        VALUE root = ARY_SHARED_ROOT(ary);
         const VALUE *ptr = ARY_HEAP_PTR(ary);
-        const VALUE *root_ptr = RARRAY_CONST_PTR_TRANSIENT(root);
+        const VALUE *root_ptr = RARRAY_CONST_PTR(root);
         long len = ARY_HEAP_LEN(ary), root_len = RARRAY_LEN(root);
-        assert(FL_TEST(root, RARRAY_SHARED_ROOT_FLAG));
-        assert(root_ptr <= ptr && ptr + len <= root_ptr + root_len);
+        RUBY_ASSERT(ARY_SHARED_ROOT_P(root) || OBJ_FROZEN(root));
+        RUBY_ASSERT(root_ptr <= ptr && ptr + len <= root_ptr + root_len);
         ary_verify(root);
     }
     else if (ARY_EMBED_P(ary)) {
-        assert(!RARRAY_TRANSIENT_P(ary));
-        assert(!ARY_SHARED_P(ary));
-        assert(RARRAY_LEN(ary) <= RARRAY_EMBED_LEN_MAX);
+        RUBY_ASSERT(!ARY_SHARED_P(ary));
+        RUBY_ASSERT(RARRAY_LEN(ary) <= ary_embed_capa(ary));
     }
     else {
-#if 1
-        const VALUE *ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+        const VALUE *ptr = RARRAY_CONST_PTR(ary);
         long i, len = RARRAY_LEN(ary);
         volatile VALUE v;
         if (len > 1) len = 1; /* check only HEAD */
@@ -201,23 +268,10 @@ ary_verify_(VALUE ary, const char *file, int line)
             v = ptr[i]; /* access check */
         }
         v = v;
-#endif
     }
 
-    if (RARRAY_TRANSIENT_P(ary)) {
-        assert(rb_transient_heap_managed_ptr_p(RARRAY_CONST_PTR_TRANSIENT(ary)));
-    }
-
-    rb_transient_heap_verify();
-
     return ary;
 }
-
-void
-rb_ary_verify(VALUE ary)
-{
-    ary_verify(ary);
-}
 #else
 #define ary_verify(ary) ((void)0)
 #endif
@@ -228,7 +282,7 @@ rb_ary_ptr_use_start(VALUE ary)
 #if ARRAY_DEBUG
     FL_SET_RAW(ary, RARRAY_PTR_IN_USE_FLAG);
 #endif
-    return (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary);
+    return (VALUE *)RARRAY_CONST_PTR(ary);
 }
 
 void
@@ -240,18 +294,18 @@ rb_ary_ptr_use_end(VALUE ary)
 }
 
 void
-rb_mem_clear(register VALUE *mem, register long size)
+rb_mem_clear(VALUE *mem, long size)
 {
     while (size--) {
-	*mem++ = Qnil;
+        *mem++ = Qnil;
     }
 }
 
 static void
 ary_mem_clear(VALUE ary, long beg, long size)
 {
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-	rb_mem_clear(ptr + beg, size);
+    RARRAY_PTR_USE(ary, ptr, {
+        rb_mem_clear(ptr + beg, size);
     });
 }
 
@@ -259,33 +313,33 @@ static inline void
 memfill(register VALUE *mem, register long size, register VALUE val)
 {
     while (size--) {
-	*mem++ = val;
+        *mem++ = val;
     }
 }
 
 static void
 ary_memfill(VALUE ary, long beg, long size, VALUE val)
 {
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-	memfill(ptr + beg, size, val);
-	RB_OBJ_WRITTEN(ary, Qundef, val);
+    RARRAY_PTR_USE(ary, ptr, {
+        memfill(ptr + beg, size, val);
+        RB_OBJ_WRITTEN(ary, Qundef, val);
     });
 }
 
 static void
 ary_memcpy0(VALUE ary, long beg, long argc, const VALUE *argv, VALUE buff_owner_ary)
 {
-    assert(!ARY_SHARED_P(buff_owner_ary));
+    RUBY_ASSERT(!ARY_SHARED_P(buff_owner_ary));
 
     if (argc > (int)(128/sizeof(VALUE)) /* is magic number (cache line size) */) {
         rb_gc_writebarrier_remember(buff_owner_ary);
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        RARRAY_PTR_USE(ary, ptr, {
             MEMCPY(ptr+beg, argv, VALUE, argc);
         });
     }
     else {
         int i;
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        RARRAY_PTR_USE(ary, ptr, {
             for (i=0; i<argc; i++) {
                 RB_OBJ_WRITE(buff_owner_ary, &ptr[i+beg], argv[i]);
             }
@@ -300,135 +354,63 @@ ary_memcpy(VALUE ary, long beg, long argc, const VALUE *argv)
 }
 
 static VALUE *
-ary_heap_alloc(VALUE ary, size_t capa)
+ary_heap_alloc_buffer(size_t capa)
 {
-    VALUE *ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * capa);
-
-    if (ptr != NULL) {
-        RARY_TRANSIENT_SET(ary);
-    }
-    else {
-        RARY_TRANSIENT_UNSET(ary);
-        ptr = ALLOC_N(VALUE, capa);
-    }
-
-    return ptr;
+    return ALLOC_N(VALUE, capa);
 }
 
 static void
 ary_heap_free_ptr(VALUE ary, const VALUE *ptr, long size)
 {
-    if (RARRAY_TRANSIENT_P(ary)) {
-        /* ignore it */
-    }
-    else {
-        ruby_sized_xfree((void *)ptr, size);
-    }
+    ruby_xfree_sized((void *)ptr, size);
 }
 
 static void
 ary_heap_free(VALUE ary)
 {
-    if (RARRAY_TRANSIENT_P(ary)) {
-        RARY_TRANSIENT_UNSET(ary);
-    }
-    else {
-        ary_heap_free_ptr(ary, ARY_HEAP_PTR(ary), ARY_HEAP_SIZE(ary));
-    }
+    ary_heap_free_ptr(ary, ARY_HEAP_PTR(ary), ARY_HEAP_SIZE(ary));
 }
 
-static void
+static size_t
 ary_heap_realloc(VALUE ary, size_t new_capa)
 {
-    size_t old_capa = ARY_HEAP_CAPA(ary);
-
-    if (RARRAY_TRANSIENT_P(ary)) {
-        if (new_capa <= old_capa) {
-            /* do nothing */
-        }
-        else {
-            VALUE *new_ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * new_capa);
-
-            if (new_ptr == NULL) {
-                new_ptr = ALLOC_N(VALUE, new_capa);
-                RARY_TRANSIENT_UNSET(ary);
-            }
-
-            MEMCPY(new_ptr, ARY_HEAP_PTR(ary), VALUE, old_capa);
-            ARY_SET_PTR(ary, new_ptr);
-        }
-    }
-    else {
-        SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, old_capa);
-    }
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
+    SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, ARY_HEAP_CAPA(ary));
     ary_verify(ary);
+
+    return new_capa;
 }
 
-#if USE_TRANSIENT_HEAP
-static inline void
-rb_ary_transient_heap_evacuate_(VALUE ary, int transient, int promote)
+void
+rb_ary_make_embedded(VALUE ary)
 {
-    if (transient) {
-        VALUE *new_ptr;
-        const VALUE *old_ptr = ARY_HEAP_PTR(ary);
+    RUBY_ASSERT(rb_ary_embeddable_p(ary));
+    if (!ARY_EMBED_P(ary)) {
+        const VALUE *buf = ARY_HEAP_PTR(ary);
+        long len = ARY_HEAP_LEN(ary);
         long capa = ARY_HEAP_CAPA(ary);
-        long len  = ARY_HEAP_LEN(ary);
-
-        if (ARY_SHARED_ROOT_P(ary)) {
-            capa = len;
-        }
 
-        assert(ARY_OWNS_HEAP_P(ary));
-        assert(RARRAY_TRANSIENT_P(ary));
-        assert(!ARY_PTR_USING_P(ary));
+        FL_SET_EMBED(ary);
+        ARY_SET_EMBED_LEN(ary, len);
 
-        if (promote) {
-            new_ptr = ALLOC_N(VALUE, capa);
-            RARY_TRANSIENT_UNSET(ary);
-        }
-        else {
-            new_ptr = ary_heap_alloc(ary, capa);
-        }
+        MEMCPY((void *)ARY_EMBED_PTR(ary), (void *)buf, VALUE, len);
 
-        MEMCPY(new_ptr, old_ptr, VALUE, capa);
-        /* do not use ARY_SET_PTR() because they assert !frozen */
-        RARRAY(ary)->as.heap.ptr = new_ptr;
+        ary_heap_free_ptr(ary, buf, capa * sizeof(VALUE));
     }
-
-    ary_verify(ary);
-}
-
-void
-rb_ary_transient_heap_evacuate(VALUE ary, int promote)
-{
-    rb_ary_transient_heap_evacuate_(ary, RARRAY_TRANSIENT_P(ary), promote);
 }
 
-void
-rb_ary_detransient(VALUE ary)
-{
-    assert(RARRAY_TRANSIENT_P(ary));
-    rb_ary_transient_heap_evacuate_(ary, TRUE, TRUE);
-}
-#else
-void
-rb_ary_detransient(VALUE ary)
-{
-    /* do nothing */
-}
-#endif
-
 static void
 ary_resize_capa(VALUE ary, long capacity)
 {
-    assert(RARRAY_LEN(ary) <= capacity);
-    assert(!OBJ_FROZEN(ary));
-    assert(!ARY_SHARED_P(ary));
+    RUBY_ASSERT(RARRAY_LEN(ary) <= capacity);
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
+    RUBY_ASSERT(!ARY_SHARED_P(ary));
 
-    if (capacity > RARRAY_EMBED_LEN_MAX) {
+    if (capacity > ary_embed_capa(ary)) {
+        size_t new_capa = capacity;
         if (ARY_EMBED_P(ary)) {
             long len = ARY_EMBED_LEN(ary);
-            VALUE *ptr = ary_heap_alloc(ary, capacity);
+            VALUE *ptr = ary_heap_alloc_buffer(capacity);
 
             MEMCPY(ptr, ARY_EMBED_PTR(ary), VALUE, len);
             FL_UNSET_EMBED(ary);
@@ -436,9 +418,9 @@ ary_resize_capa(VALUE ary, long capacity)
             ARY_SET_HEAP_LEN(ary, len);
         }
         else {
-            ary_heap_realloc(ary, capacity);
+            new_capa = ary_heap_realloc(ary, capacity);
         }
-        ARY_SET_CAPA(ary, capacity);
+        ARY_SET_CAPA(ary, new_capa);
     }
     else {
         if (!ARY_EMBED_P(ary)) {
@@ -448,7 +430,7 @@ ary_resize_capa(VALUE ary, long capacity)
 
             if (len > capacity) len = capacity;
             MEMCPY((VALUE *)RARRAY(ary)->as.ary, ptr, VALUE, len);
-            ary_heap_free_ptr(ary, ptr, old_capa);
+            ary_heap_free_ptr(ary, ptr, old_capa * sizeof(VALUE));
 
             FL_SET_EMBED(ary);
             ARY_SET_LEN(ary, len);
@@ -463,9 +445,12 @@ ary_shrink_capa(VALUE ary)
 {
     long capacity = ARY_HEAP_LEN(ary);
     long old_capa = ARY_HEAP_CAPA(ary);
-    assert(!ARY_SHARED_P(ary));
-    assert(old_capa >= capacity);
-    if (old_capa > capacity) ary_heap_realloc(ary, capacity);
+    RUBY_ASSERT(!ARY_SHARED_P(ary));
+    RUBY_ASSERT(old_capa >= capacity);
+    if (old_capa > capacity) {
+        size_t new_capa = ary_heap_realloc(ary, capacity);
+        ARY_SET_CAPA(ary, new_capa);
+    }
 
     ary_verify(ary);
 }
@@ -476,10 +461,10 @@ ary_double_capa(VALUE ary, long min)
     long new_capa = ARY_CAPA(ary) / 2;
 
     if (new_capa < ARY_DEFAULT_SIZE) {
-	new_capa = ARY_DEFAULT_SIZE;
+        new_capa = ARY_DEFAULT_SIZE;
     }
     if (new_capa >= ARY_MAX_SIZE - min) {
-	new_capa = (ARY_MAX_SIZE - min) / 2;
+        new_capa = (ARY_MAX_SIZE - min) / 2;
     }
     new_capa += min;
     ary_resize_capa(ary, new_capa);
@@ -490,39 +475,40 @@ ary_double_capa(VALUE ary, long min)
 static void
 rb_ary_decrement_share(VALUE shared_root)
 {
-    if (shared_root) {
-        long num = ARY_SHARED_ROOT_REFCNT(shared_root) - 1;
-	if (num == 0) {
-            rb_ary_free(shared_root);
-            rb_gc_force_recycle(shared_root);
-	}
-	else if (num > 0) {
-            ARY_SET_SHARED_ROOT_REFCNT(shared_root, num);
-	}
+    if (!OBJ_FROZEN(shared_root)) {
+        long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+        ARY_SET_SHARED_ROOT_REFCNT(shared_root, num - 1);
     }
 }
 
 static void
 rb_ary_unshare(VALUE ary)
 {
-    VALUE shared_root = RARRAY(ary)->as.heap.aux.shared_root;
+    VALUE shared_root = ARY_SHARED_ROOT(ary);
     rb_ary_decrement_share(shared_root);
     FL_UNSET_SHARED(ary);
 }
 
-static inline void
-rb_ary_unshare_safe(VALUE ary)
+static void
+rb_ary_reset(VALUE ary)
 {
-    if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
-	rb_ary_unshare(ary);
+    if (ARY_OWNS_HEAP_P(ary)) {
+        ary_heap_free(ary);
+    }
+    else if (ARY_SHARED_P(ary)) {
+        rb_ary_unshare(ary);
     }
+
+    FL_SET_EMBED(ary);
+    ARY_SET_EMBED_LEN(ary, 0);
 }
 
 static VALUE
 rb_ary_increment_share(VALUE shared_root)
 {
-    long num = ARY_SHARED_ROOT_REFCNT(shared_root);
-    if (num >= 0) {
+    if (!OBJ_FROZEN(shared_root)) {
+        long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+        RUBY_ASSERT(num >= 0);
         ARY_SET_SHARED_ROOT_REFCNT(shared_root, num + 1);
     }
     return shared_root;
@@ -531,61 +517,74 @@ rb_ary_increment_share(VALUE shared_root)
 static void
 rb_ary_set_shared(VALUE ary, VALUE shared_root)
 {
+    RUBY_ASSERT(!ARY_EMBED_P(ary));
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
+    RUBY_ASSERT(ARY_SHARED_ROOT_P(shared_root) || OBJ_FROZEN(shared_root));
+
     rb_ary_increment_share(shared_root);
     FL_SET_SHARED(ary);
+    RB_OBJ_WRITE(ary, &RARRAY(ary)->as.heap.aux.shared_root, shared_root);
+
     RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
-    ARY_SET_SHARED(ary, shared_root);
 }
 
 static inline void
 rb_ary_modify_check(VALUE ary)
 {
+    RUBY_ASSERT(ruby_thread_has_gvl_p());
+
     rb_check_frozen(ary);
     ary_verify(ary);
 }
 
 void
-rb_ary_modify(VALUE ary)
+rb_ary_cancel_sharing(VALUE ary)
 {
-    rb_ary_modify_check(ary);
     if (ARY_SHARED_P(ary)) {
-	long shared_len, len = RARRAY_LEN(ary);
+        long shared_len, len = RARRAY_LEN(ary);
         VALUE shared_root = ARY_SHARED_ROOT(ary);
 
         ary_verify(shared_root);
 
-        if (len <= RARRAY_EMBED_LEN_MAX) {
-	    const VALUE *ptr = ARY_HEAP_PTR(ary);
+        if (len <= ary_embed_capa(ary)) {
+            const VALUE *ptr = ARY_HEAP_PTR(ary);
             FL_UNSET_SHARED(ary);
             FL_SET_EMBED(ary);
-	    MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len);
+            MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len);
             rb_ary_decrement_share(shared_root);
             ARY_SET_EMBED_LEN(ary, len);
         }
         else if (ARY_SHARED_ROOT_OCCUPIED(shared_root) && len > ((shared_len = RARRAY_LEN(shared_root))>>1)) {
-            long shift = RARRAY_CONST_PTR_TRANSIENT(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root);
-	    FL_UNSET_SHARED(ary);
-            ARY_SET_PTR(ary, RARRAY_CONST_PTR_TRANSIENT(shared_root));
-	    ARY_SET_CAPA(ary, shared_len);
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-		MEMMOVE(ptr, ptr+shift, VALUE, len);
-	    });
+            long shift = RARRAY_CONST_PTR(ary) - RARRAY_CONST_PTR(shared_root);
+            FL_UNSET_SHARED(ary);
+            ARY_SET_PTR(ary, RARRAY_CONST_PTR(shared_root));
+            ARY_SET_CAPA(ary, shared_len);
+            RARRAY_PTR_USE(ary, ptr, {
+                MEMMOVE(ptr, ptr+shift, VALUE, len);
+            });
             FL_SET_EMBED(shared_root);
             rb_ary_decrement_share(shared_root);
-	}
+        }
         else {
-            VALUE *ptr = ary_heap_alloc(ary, len);
+            VALUE *ptr = ary_heap_alloc_buffer(len);
             MEMCPY(ptr, ARY_HEAP_PTR(ary), VALUE, len);
             rb_ary_unshare(ary);
-            ARY_SET_CAPA(ary, len);
-            ARY_SET_PTR(ary, ptr);
+            ARY_SET_CAPA_FORCE(ary, len);
+            ARY_SET_PTR_FORCE(ary, ptr);
         }
 
-	rb_gc_writebarrier_remember(ary);
+        rb_gc_writebarrier_remember(ary);
     }
     ary_verify(ary);
 }
 
+void
+rb_ary_modify(VALUE ary)
+{
+    rb_ary_modify_check(ary);
+    rb_ary_cancel_sharing(ary);
+}
+
 static VALUE
 ary_ensure_room_for_push(VALUE ary, long add_len)
 {
@@ -594,40 +593,40 @@ ary_ensure_room_for_push(VALUE ary, long add_len)
     long capa;
 
     if (old_len > ARY_MAX_SIZE - add_len) {
-	rb_raise(rb_eIndexError, "index %ld too big", new_len);
+        rb_raise(rb_eIndexError, "index %ld too big", new_len);
     }
     if (ARY_SHARED_P(ary)) {
-	if (new_len > RARRAY_EMBED_LEN_MAX) {
+        if (new_len > ary_embed_capa(ary)) {
             VALUE shared_root = ARY_SHARED_ROOT(ary);
             if (ARY_SHARED_ROOT_OCCUPIED(shared_root)) {
-                if (ARY_HEAP_PTR(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root) + new_len <= RARRAY_LEN(shared_root)) {
-		    rb_ary_modify_check(ary);
+                if (ARY_HEAP_PTR(ary) - RARRAY_CONST_PTR(shared_root) + new_len <= RARRAY_LEN(shared_root)) {
+                    rb_ary_modify_check(ary);
 
                     ary_verify(ary);
                     ary_verify(shared_root);
                     return shared_root;
-		}
-		else {
-		    /* if array is shared, then it is likely it participate in push/shift pattern */
-		    rb_ary_modify(ary);
-		    capa = ARY_CAPA(ary);
-		    if (new_len > capa - (capa >> 6)) {
-			ary_double_capa(ary, new_len);
-		    }
+                }
+                else {
+                    /* if array is shared, then it is likely it participate in push/shift pattern */
+                    rb_ary_modify(ary);
+                    capa = ARY_CAPA(ary);
+                    if (new_len > capa - (capa >> 6)) {
+                        ary_double_capa(ary, new_len);
+                    }
                     ary_verify(ary);
-		    return ary;
-		}
-	    }
-	}
+                    return ary;
+                }
+            }
+        }
         ary_verify(ary);
         rb_ary_modify(ary);
     }
     else {
-	rb_ary_modify_check(ary);
+        rb_ary_modify_check(ary);
     }
     capa = ARY_CAPA(ary);
     if (new_len > capa) {
-	ary_double_capa(ary, new_len);
+        ary_double_capa(ary, new_len);
     }
 
     ary_verify(ary);
@@ -636,17 +635,32 @@ ary_ensure_room_for_push(VALUE ary, long add_len)
 
 /*
  *  call-seq:
- *      ary.freeze -> ary
+ *    freeze -> self
  *
- *  Calls Object#freeze on +ary+ to prevent any further
- *  modification. A RuntimeError will be raised if a modification
- *  attempt is made.
+ *  Freezes +self+ (if not already frozen); returns +self+:
  *
+ *    a = []
+ *    a.frozen? # => false
+ *    a.freeze
+ *    a.frozen? # => true
+ *
+ *  No further changes may be made to +self+;
+ *  raises FrozenError if a change is attempted.
+ *
+ *  Related: Kernel#frozen?.
  */
 
 VALUE
 rb_ary_freeze(VALUE ary)
 {
+    RUBY_ASSERT(RB_TYPE_P(ary, T_ARRAY));
+
+    if (OBJ_FROZEN(ary)) return ary;
+
+    if (!ARY_EMBED_P(ary) && !ARY_SHARED_P(ary) && !ARY_SHARED_ROOT_P(ary)) {
+        ary_shrink_capa(ary);
+    }
+
     return rb_obj_freeze(ary);
 }
 
@@ -661,22 +675,35 @@ VALUE
 rb_ary_shared_with_p(VALUE ary1, VALUE ary2)
 {
     if (!ARY_EMBED_P(ary1) && ARY_SHARED_P(ary1) &&
-	!ARY_EMBED_P(ary2) && ARY_SHARED_P(ary2) &&
-        RARRAY(ary1)->as.heap.aux.shared_root == RARRAY(ary2)->as.heap.aux.shared_root &&
-	RARRAY(ary1)->as.heap.len == RARRAY(ary2)->as.heap.len) {
-	return Qtrue;
+            !ARY_EMBED_P(ary2) && ARY_SHARED_P(ary2) &&
+            ARY_SHARED_ROOT(ary1) == ARY_SHARED_ROOT(ary2) &&
+            ARY_HEAP_LEN(ary1) == ARY_HEAP_LEN(ary2)) {
+        return Qtrue;
     }
     return Qfalse;
 }
 
 static VALUE
-ary_alloc(VALUE klass)
+ary_alloc_embed(VALUE klass, long capa)
 {
-    NEWOBJ_OF(ary, struct RArray, klass, T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0));
-    /* Created array is:
-     *   FL_SET_EMBED((VALUE)ary);
-     *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
-     */
+    size_t size = ary_embed_size(capa);
+    RUBY_ASSERT(rb_gc_size_allocatable_p(size));
+   /* Created array is:
+    *   FL_SET_EMBED((VALUE)ary);
+    *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
+    */
+    return rb_newobj_of(klass, T_ARRAY | RARRAY_EMBED_FLAG, size);
+}
+
+static VALUE
+ary_alloc_heap(VALUE klass)
+{
+    NEWOBJ_OF(ary, struct RArray, klass, T_ARRAY, sizeof(struct RArray));
+
+    ary->as.heap.len = 0;
+    ary->as.heap.aux.capa = 0;
+    ary->as.heap.ptr = NULL;
+
     return (VALUE)ary;
 }
 
@@ -684,29 +711,34 @@ static VALUE
 empty_ary_alloc(VALUE klass)
 {
     RUBY_DTRACE_CREATE_HOOK(ARRAY, 0);
-    return ary_alloc(klass);
+    return ary_alloc_embed(klass, 0);
 }
 
 static VALUE
 ary_new(VALUE klass, long capa)
 {
-    VALUE ary,*ptr;
+    RUBY_ASSERT(ruby_thread_has_gvl_p());
+
+    VALUE ary;
 
     if (capa < 0) {
-	rb_raise(rb_eArgError, "negative array size (or size too big)");
+        rb_raise(rb_eArgError, "negative array size (or size too big)");
     }
     if (capa > ARY_MAX_SIZE) {
-	rb_raise(rb_eArgError, "array size too big");
+        rb_raise(rb_eArgError, "array size too big");
     }
 
     RUBY_DTRACE_CREATE_HOOK(ARRAY, capa);
 
-    ary = ary_alloc(klass);
-    if (capa > RARRAY_EMBED_LEN_MAX) {
-        ptr = ary_heap_alloc(ary, capa);
-        FL_UNSET_EMBED(ary);
-        ARY_SET_PTR(ary, ptr);
+    if (ary_embeddable_p(capa)) {
+        ary = ary_alloc_embed(klass, capa);
+    }
+    else {
+        ary = ary_alloc_heap(klass);
         ARY_SET_CAPA(ary, capa);
+        RUBY_ASSERT(!ARY_EMBED_P(ary));
+
+        ARY_SET_PTR(ary, ary_heap_alloc_buffer(capa));
         ARY_SET_HEAP_LEN(ary, 0);
     }
 
@@ -722,7 +754,7 @@ rb_ary_new_capa(long capa)
 VALUE
 rb_ary_new(void)
 {
-    return rb_ary_new2(RARRAY_EMBED_LEN_MAX);
+    return rb_ary_new_capa(0);
 }
 
 VALUE
@@ -736,7 +768,7 @@ VALUE
 
     va_start(ar, n);
     for (i=0; i<n; i++) {
-	ARY_SET(ary, i, va_arg(ar, VALUE));
+        ARY_SET(ary, i, va_arg(ar, VALUE));
     }
     va_end(ar);
 
@@ -744,15 +776,15 @@ VALUE
     return ary;
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_ary_tmp_new_from_values(VALUE klass, long n, const VALUE *elts)
 {
     VALUE ary;
 
     ary = ary_new(klass, n);
     if (n > 0 && elts) {
-	ary_memcpy(ary, 0, n, elts);
-	ARY_SET_LEN(ary, n);
+        ary_memcpy(ary, 0, n, elts);
+        ARY_SET_LEN(ary, n);
     }
 
     return ary;
@@ -764,21 +796,84 @@ rb_ary_new_from_values(long n, const VALUE *elts)
     return rb_ary_tmp_new_from_values(rb_cArray, n, elts);
 }
 
+static VALUE
+ec_ary_alloc_embed(rb_execution_context_t *ec, VALUE klass, long capa)
+{
+    size_t size = ary_embed_size(capa);
+    RUBY_ASSERT(rb_gc_size_allocatable_p(size));
+   /* Created array is:
+    *   FL_SET_EMBED((VALUE)ary);
+    *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
+    */
+    return rb_ec_newobj_of(ec, klass, T_ARRAY | RARRAY_EMBED_FLAG, size);
+}
+
+static VALUE
+ec_ary_alloc_heap(rb_execution_context_t *ec, VALUE klass)
+{
+    VALUE ary = rb_ec_newobj_of(ec, klass, T_ARRAY, sizeof(struct RArray));
+    RARRAY(ary)->as.heap.len = 0;
+    RARRAY(ary)->as.heap.aux.capa = 0;
+    RARRAY(ary)->as.heap.ptr = NULL;
+    return ary;
+}
+
+static VALUE
+ec_ary_new(rb_execution_context_t *ec, VALUE klass, long capa)
+{
+    VALUE ary;
+
+    if (capa < 0) {
+        rb_raise(rb_eArgError, "negative array size (or size too big)");
+    }
+    if (capa > ARY_MAX_SIZE) {
+        rb_raise(rb_eArgError, "array size too big");
+    }
+
+    RUBY_DTRACE_CREATE_HOOK(ARRAY, capa);
+
+    if (ary_embeddable_p(capa)) {
+        ary = ec_ary_alloc_embed(ec, klass, capa);
+    }
+    else {
+        ary = ec_ary_alloc_heap(ec, klass);
+        ARY_SET_CAPA(ary, capa);
+        RUBY_ASSERT(!ARY_EMBED_P(ary));
+
+        ARY_SET_PTR(ary, ary_heap_alloc_buffer(capa));
+        ARY_SET_HEAP_LEN(ary, 0);
+    }
+
+    return ary;
+}
+
 VALUE
-rb_ary_tmp_new(long capa)
+rb_ec_ary_new_from_values(rb_execution_context_t *ec, long n, const VALUE *elts)
 {
-    VALUE ary = ary_new(0, capa);
-    rb_ary_transient_heap_evacuate(ary, TRUE);
+    VALUE ary;
+
+    ary = ec_ary_new(ec, rb_cArray, n);
+    if (n > 0 && elts) {
+        ary_memcpy(ary, 0, n, elts);
+        ARY_SET_LEN(ary, n);
+    }
+
     return ary;
 }
 
 VALUE
-rb_ary_tmp_new_fill(long capa)
+rb_ary_hidden_new(long capa)
 {
     VALUE ary = ary_new(0, capa);
+    return ary;
+}
+
+VALUE
+rb_ary_hidden_new_fill(long capa)
+{
+    VALUE ary = rb_ary_hidden_new(capa);
     ary_memfill(ary, 0, capa, Qnil);
     ARY_SET_LEN(ary, capa);
-    rb_ary_transient_heap_evacuate(ary, TRUE);
     return ary;
 }
 
@@ -792,13 +887,8 @@ rb_ary_free(VALUE ary)
             RB_DEBUG_COUNTER_INC(obj_ary_extracapa);
         }
 
-        if (RARRAY_TRANSIENT_P(ary)) {
-            RB_DEBUG_COUNTER_INC(obj_ary_transient);
-        }
-        else {
-            RB_DEBUG_COUNTER_INC(obj_ary_ptr);
-            ary_heap_free(ary);
-        }
+        RB_DEBUG_COUNTER_INC(obj_ary_ptr);
+        ary_heap_free(ary);
     }
     else {
         RB_DEBUG_COUNTER_INC(obj_ary_embed);
@@ -812,67 +902,87 @@ rb_ary_free(VALUE ary)
     }
 }
 
-RUBY_FUNC_EXPORTED size_t
+static VALUE fake_ary_flags;
+
+static VALUE
+init_fake_ary_flags(void)
+{
+    struct RArray fake_ary = {0};
+    fake_ary.basic.flags = T_ARRAY;
+    VALUE ary = (VALUE)&fake_ary;
+    RBASIC_SET_SHAPE_ID(ary, ROOT_SHAPE_ID | SHAPE_ID_LAYOUT_OTHER);
+    rb_ary_freeze(ary);
+    return fake_ary.basic.flags;
+}
+
+VALUE
+rb_setup_fake_ary(struct RArray *fake_ary, const VALUE *list, long len)
+{
+    fake_ary->basic.flags = fake_ary_flags;
+    RBASIC_CLEAR_CLASS((VALUE)fake_ary);
+
+    // bypass frozen checks
+    fake_ary->as.heap.ptr = list;
+    fake_ary->as.heap.len = len;
+    fake_ary->as.heap.aux.capa = len;
+    return (VALUE)fake_ary;
+}
+
+size_t
 rb_ary_memsize(VALUE ary)
 {
     if (ARY_OWNS_HEAP_P(ary)) {
-	return ARY_CAPA(ary) * sizeof(VALUE);
+        return ARY_CAPA(ary) * sizeof(VALUE);
     }
     else {
-	return 0;
+        return 0;
     }
 }
 
-static inline void
-ary_discard(VALUE ary)
-{
-    rb_ary_free(ary);
-    RBASIC(ary)->flags |= RARRAY_EMBED_FLAG;
-    RBASIC(ary)->flags &= ~(RARRAY_EMBED_LEN_MASK | RARRAY_TRANSIENT_FLAG);
-}
-
 static VALUE
 ary_make_shared(VALUE ary)
 {
-    assert(!ARY_EMBED_P(ary));
     ary_verify(ary);
 
     if (ARY_SHARED_P(ary)) {
         return ARY_SHARED_ROOT(ary);
     }
     else if (ARY_SHARED_ROOT_P(ary)) {
-	return ary;
+        return ary;
     }
     else if (OBJ_FROZEN(ary)) {
-        rb_ary_transient_heap_evacuate(ary, TRUE);
-	ary_shrink_capa(ary);
-	FL_SET_SHARED_ROOT(ary);
-        ARY_SET_SHARED_ROOT_REFCNT(ary, 1);
-	return ary;
+        return ary;
     }
     else {
-	long capa = ARY_CAPA(ary), len = RARRAY_LEN(ary);
-        const VALUE *ptr;
-	NEWOBJ_OF(shared, struct RArray, 0, T_ARRAY | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0));
-
-        rb_ary_transient_heap_evacuate(ary, TRUE);
-        ptr = ARY_HEAP_PTR(ary);
-
-        FL_UNSET_EMBED(shared);
-	ARY_SET_LEN((VALUE)shared, capa);
-        ARY_SET_PTR((VALUE)shared, ptr);
-        ary_mem_clear((VALUE)shared, len, capa - len);
-	FL_SET_SHARED_ROOT(shared);
-        ARY_SET_SHARED_ROOT_REFCNT((VALUE)shared, 1);
-	FL_SET_SHARED(ary);
-        RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
-	ARY_SET_SHARED(ary, (VALUE)shared);
-	OBJ_FREEZE(shared);
-
-        ary_verify((VALUE)shared);
+        long capa = ARY_CAPA(ary);
+        long len = RARRAY_LEN(ary);
+
+        /* Shared roots cannot be embedded because the reference count
+         * (refcnt) is stored in as.heap.aux.capa. */
+        VALUE shared = ary_alloc_heap(0);
+        FL_SET_SHARED_ROOT(shared);
+
+        if (ARY_EMBED_P(ary)) {
+            VALUE *ptr = ary_heap_alloc_buffer(capa);
+            ARY_SET_PTR(shared, ptr);
+            ary_memcpy(shared, 0, len, RARRAY_CONST_PTR(ary));
+
+            FL_UNSET_EMBED(ary);
+            ARY_SET_HEAP_LEN(ary, len);
+            ARY_SET_PTR(ary, ptr);
+        }
+        else {
+            ARY_SET_PTR(shared, RARRAY_CONST_PTR(ary));
+        }
+
+        ARY_SET_LEN(shared, capa);
+        ary_mem_clear(shared, len, capa - len);
+        rb_ary_set_shared(ary, shared);
+
+        ary_verify(shared);
         ary_verify(ary);
 
-        return (VALUE)shared;
+        return shared;
     }
 }
 
@@ -881,9 +991,11 @@ ary_make_substitution(VALUE ary)
 {
     long len = RARRAY_LEN(ary);
 
-    if (len <= RARRAY_EMBED_LEN_MAX) {
-	VALUE subst = rb_ary_new2(len);
-        ary_memcpy(subst, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary));
+    if (ary_embeddable_p(len)) {
+        VALUE subst = rb_ary_new_capa(len);
+        RUBY_ASSERT(ARY_EMBED_P(subst));
+
+        ary_memcpy(subst, 0, len, RARRAY_CONST_PTR(ary));
         ARY_SET_EMBED_LEN(subst, len);
         return subst;
     }
@@ -911,29 +1023,34 @@ rb_check_array_type(VALUE ary)
     return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_ary);
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_check_to_array(VALUE ary)
 {
     return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_a);
 }
 
+VALUE
+rb_to_array(VALUE ary)
+{
+    return rb_convert_type_with_id(ary, T_ARRAY, "Array", idTo_a);
+}
+
 /*
  *  call-seq:
- *     Array.try_convert(obj) -> array or nil
+ *    Array.try_convert(object) -> object, new_array, or nil
+ *
+ *  Attempts to return an array, based on the given +object+.
  *
- *  Tries to convert +obj+ into an array, using the +to_ary+ method.  Returns
- *  the converted array or +nil+ if +obj+ cannot be converted.
- *  This method can be used to check if an argument is an array.
+ *  If +object+ is an array, returns +object+.
  *
- *     Array.try_convert([1])   #=> [1]
- *     Array.try_convert("1")   #=> nil
+ *  Otherwise if +object+ responds to <tt>:to_ary</tt>.
+ *  calls <tt>object.to_ary</tt>:
+ *  if the return value is an array or +nil+, returns that value;
+ *  if not, raises TypeError.
  *
- *     if tmp = Array.try_convert(arg)
- *       # the argument is an array
- *     elsif tmp = String.try_convert(arg)
- *       # the argument is a string
- *     end
+ *  Otherwise returns +nil+.
  *
+ *  Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -942,60 +1059,79 @@ rb_ary_s_try_convert(VALUE dummy, VALUE ary)
     return rb_check_array_type(ary);
 }
 
+/* :nodoc: */
+static VALUE
+rb_ary_s_new(int argc, VALUE *argv, VALUE klass)
+{
+    VALUE ary;
+
+    if (klass == rb_cArray) {
+        long size = 0;
+        if (argc > 0 && FIXNUM_P(argv[0])) {
+            size = FIX2LONG(argv[0]);
+            if (size < 0) size = 0;
+        }
+
+        ary = ary_new(klass, size);
+
+        rb_obj_call_init_kw(ary, argc, argv, RB_PASS_CALLED_KEYWORDS);
+    }
+    else {
+        ary = rb_class_new_instance_pass_kw(argc, argv, klass);
+    }
+
+    return ary;
+}
+
 /*
  *  call-seq:
- *     Array.new(size=0, default=nil)
- *     Array.new(array)
- *     Array.new(size) {|index| block }
+ *    Array.new -> new_empty_array
+ *    Array.new(array) -> new_array
+ *    Array.new(size, default_value = nil) -> new_array
+ *    Array.new(size = 0) {|index| ... } -> new_array
  *
  *  Returns a new array.
  *
- *  In the first form, if no arguments are sent, the new array will be empty.
- *  When a +size+ and an optional +default+ are sent, an array is created with
- *  +size+ copies of +default+.  Take notice that all elements will reference the
- *  same object +default+.
- *
- *  The second form creates a copy of the array passed as a parameter (the
- *  array is generated by calling to_ary on the parameter).
+ *  With no block and no argument given, returns a new empty array:
  *
- *    first_array = ["Matz", "Guido"]
+ *    Array.new # => []
  *
- *    second_array = Array.new(first_array) #=> ["Matz", "Guido"]
+ *  With no block and array argument given, returns a new array with the same elements:
  *
- *    first_array.equal? second_array       #=> false
+ *    Array.new([:foo, 'bar', 2]) # => [:foo, "bar", 2]
  *
- *  In the last form, an array of the given size is created.  Each element in
- *  this array is created by passing the element's index to the given block
- *  and storing the return value.
+ *  With no block and integer argument given, returns a new array containing
+ *  that many instances of the given +default_value+:
  *
- *    Array.new(3) {|index| index ** 2}
- *    # => [0, 1, 4]
+ *    Array.new(0)    # => []
+ *    Array.new(3)    # => [nil, nil, nil]
+ *    Array.new(2, 3) # => [3, 3]
  *
- *  == Common gotchas
+ *  With a block given, returns an array of the given +size+;
+ *  calls the block with each +index+ in the range <tt>(0...size)</tt>;
+ *  the element at that +index+ in the returned array is the blocks return value:
  *
- *  When sending the second parameter, the same object will be used as the
- *  value for all the array elements:
+ *    Array.new(3)  {|index| "Element #{index}" } # => ["Element 0", "Element 1", "Element 2"]
  *
- *     a = Array.new(2, Hash.new)
- *     # => [{}, {}]
+ *  A common pitfall for new Rubyists is providing an expression as +default_value+:
  *
- *     a[0]['cat'] = 'feline'
- *     a # => [{"cat"=>"feline"}, {"cat"=>"feline"}]
+ *    array = Array.new(2, {})
+ *    array # => [{}, {}]
+ *    array[0][:a] = 1
+ *    array # => [{a: 1}, {a: 1}], as array[0] and array[1] are same object
  *
- *     a[1]['cat'] = 'Felix'
- *     a # => [{"cat"=>"Felix"}, {"cat"=>"Felix"}]
+ *  If you want the elements of the array to be distinct, you should pass a block:
  *
- *  Since all the Array elements store the same hash, changes to one of them
- *  will affect them all.
+ *    array = Array.new(2) { {} }
+ *    array # => [{}, {}]
+ *    array[0][:a] = 1
+ *    array # => [{a: 1}, {}], as array[0] and array[1] are different objects
  *
- *  If multiple copies are what you want, you should use the block
- *  version which uses the result of that block each time an element
- *  of the array needs to be initialized:
- *
- *     a = Array.new(2) {Hash.new}
- *     a[0]['cat'] = 'feline'
- *     a # => [{"cat"=>"feline"}, {}]
+ *  Raises TypeError if the first argument is not either an array
+ *  or an {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]).
+ *  Raises ArgumentError if the first argument is a negative integer.
  *
+ *  Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1006,61 +1142,60 @@ rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
 
     rb_ary_modify(ary);
     if (argc == 0) {
-        if (ARY_OWNS_HEAP_P(ary) && ARY_HEAP_PTR(ary) != NULL) {
-            ary_heap_free(ary);
-	}
-        rb_ary_unshare_safe(ary);
-        FL_SET_EMBED(ary);
-	ARY_SET_EMBED_LEN(ary, 0);
-	if (rb_block_given_p()) {
-	    rb_warning("given block not used");
-	}
-	return ary;
+        rb_ary_reset(ary);
+        RUBY_ASSERT(ARY_EMBED_P(ary));
+        RUBY_ASSERT(ARY_EMBED_LEN(ary) == 0);
+        if (rb_block_given_p()) {
+            rb_warning("given block not used");
+        }
+        return ary;
     }
     rb_scan_args(argc, argv, "02", &size, &val);
     if (argc == 1 && !FIXNUM_P(size)) {
-	val = rb_check_array_type(size);
-	if (!NIL_P(val)) {
-	    rb_ary_replace(ary, val);
-	    return ary;
-	}
+        val = rb_check_array_type(size);
+        if (!NIL_P(val)) {
+            rb_ary_replace(ary, val);
+            return ary;
+        }
     }
 
     len = NUM2LONG(size);
     /* NUM2LONG() may call size.to_int, ary can be frozen, modified, etc */
     if (len < 0) {
-	rb_raise(rb_eArgError, "negative array size");
+        rb_raise(rb_eArgError, "negative array size");
     }
     if (len > ARY_MAX_SIZE) {
-	rb_raise(rb_eArgError, "array size too big");
+        rb_raise(rb_eArgError, "array size too big");
     }
     /* recheck after argument conversion */
     rb_ary_modify(ary);
     ary_resize_capa(ary, len);
     if (rb_block_given_p()) {
-	long i;
+        long i;
 
-	if (argc == 2) {
-	    rb_warn("block supersedes default value argument");
-	}
-	for (i=0; i<len; i++) {
-	    rb_ary_store(ary, i, rb_yield(LONG2NUM(i)));
-	    ARY_SET_LEN(ary, i + 1);
-	}
+        if (argc == 2) {
+            rb_warn("block supersedes default value argument");
+        }
+        for (i=0; i<len; i++) {
+            rb_ary_store(ary, i, rb_yield(LONG2NUM(i)));
+            ARY_SET_LEN(ary, i + 1);
+        }
     }
     else {
-	ary_memfill(ary, 0, len, val);
-	ARY_SET_LEN(ary, len);
+        ary_memfill(ary, 0, len, val);
+        ARY_SET_LEN(ary, len);
     }
     return ary;
 }
 
 /*
- * Returns a new array populated with the given objects.
+ * Returns a new array, populated with the given objects:
+ *
+ *   Array[1, 'a', /^A/]    # => [1, "a", /^A/]
+ *   Array[]                # => []
+ *   Array.[](1, 'a', /^A/) # => [1, "a", /^A/]
  *
- *   Array.[]( 1, 'a', /^A/)  # => [1, "a", /^A/]
- *   Array[ 1, 'a', /^A/ ]    # => [1, "a", /^A/]
- *   [ 1, 'a', /^A/ ]         # => [1, "a", /^A/]
+ * Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1081,26 +1216,26 @@ rb_ary_store(VALUE ary, long idx, VALUE val)
     long len = RARRAY_LEN(ary);
 
     if (idx < 0) {
-	idx += len;
-	if (idx < 0) {
-	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
-		     idx - len, -len);
-	}
+        idx += len;
+        if (idx < 0) {
+            rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+                     idx - len, -len);
+        }
     }
     else if (idx >= ARY_MAX_SIZE) {
-	rb_raise(rb_eIndexError, "index %ld too big", idx);
+        rb_raise(rb_eIndexError, "index %ld too big", idx);
     }
 
     rb_ary_modify(ary);
     if (idx >= ARY_CAPA(ary)) {
-	ary_double_capa(ary, idx);
+        ary_double_capa(ary, idx);
     }
     if (idx > len) {
-	ary_mem_clear(ary, len, idx - len + 1);
+        ary_mem_clear(ary, len, idx - len + 1);
     }
 
     if (idx >= len) {
-	ARY_SET_LEN(ary, idx + 1);
+        ARY_SET_LEN(ary, idx + 1);
     }
     ARY_SET(ary, idx, val);
 }
@@ -1108,22 +1243,26 @@ rb_ary_store(VALUE ary, long idx, VALUE val)
 static VALUE
 ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
 {
-    assert(offset >= 0);
-    assert(len >= 0);
-    assert(offset+len <= RARRAY_LEN(ary));
+    RUBY_ASSERT(offset >= 0);
+    RUBY_ASSERT(len >= 0);
+    RUBY_ASSERT(offset+len <= RARRAY_LEN(ary));
 
-    if (len <= RARRAY_EMBED_LEN_MAX) {
-        VALUE result = ary_alloc(klass);
-        ary_memcpy(result, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary) + offset);
+    VALUE result = ary_alloc_heap(klass);
+    size_t embed_capa = ary_embed_capa(result);
+    if ((size_t)len <= embed_capa) {
+        FL_SET_EMBED(result);
+        ary_memcpy(result, 0, len, RARRAY_CONST_PTR(ary) + offset);
         ARY_SET_EMBED_LEN(result, len);
-        return result;
     }
     else {
-        VALUE shared, result = ary_alloc(klass);
+        VALUE shared = ary_make_shared(ary);
+
+        /* The ary_make_shared call may allocate, which can trigger a GC
+         * compaction. This can cause the array to be embedded because it has
+         * a length of 0. */
         FL_UNSET_EMBED(result);
 
-        shared = ary_make_shared(ary);
-        ARY_SET_PTR(result, RARRAY_CONST_PTR_TRANSIENT(ary));
+        ARY_SET_PTR(result, RARRAY_CONST_PTR(ary));
         ARY_SET_LEN(result, RARRAY_LEN(ary));
         rb_ary_set_shared(result, shared);
 
@@ -1131,15 +1270,71 @@ ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
         ARY_SET_LEN(result, len);
 
         ary_verify(shared);
-        ary_verify(result);
+    }
+
+    ary_verify(result);
+    return result;
+}
+
+static VALUE
+ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
+{
+    RUBY_ASSERT(offset >= 0);
+    RUBY_ASSERT(len >= 0);
+    RUBY_ASSERT(offset+len <= RARRAY_LEN(ary));
+    RUBY_ASSERT(step != 0);
+
+    const long orig_len = len;
+
+    if (step > 0 && step >= len) {
+        VALUE result = ary_new(klass, 1);
+        VALUE *ptr = (VALUE *)ARY_EMBED_PTR(result);
+        const VALUE *values = RARRAY_CONST_PTR(ary);
+
+        RB_OBJ_WRITE(result, ptr, values[offset]);
+        ARY_SET_EMBED_LEN(result, 1);
         return result;
     }
+    else if (step < 0 && step < -len) {
+        step = -len;
+    }
+
+    long ustep = (step < 0) ? -step : step;
+    len = roomof(len, ustep);
+
+    long i;
+    long j = offset + ((step > 0) ? 0 : (orig_len - 1));
+
+    VALUE result = ary_new(klass, len);
+    if (ARY_EMBED_P(result)) {
+        VALUE *ptr = (VALUE *)ARY_EMBED_PTR(result);
+        const VALUE *values = RARRAY_CONST_PTR(ary);
+
+        for (i = 0; i < len; ++i) {
+            RB_OBJ_WRITE(result, ptr+i, values[j]);
+            j += step;
+        }
+        ARY_SET_EMBED_LEN(result, len);
+    }
+    else {
+        const VALUE *values = RARRAY_CONST_PTR(ary);
+
+        RARRAY_PTR_USE(result, ptr, {
+            for (i = 0; i < len; ++i) {
+                RB_OBJ_WRITE(result, ptr+i, values[j]);
+                j += step;
+            }
+        });
+        ARY_SET_LEN(result, len);
+    }
+
+    return result;
 }
 
 static VALUE
 ary_make_shared_copy(VALUE ary)
 {
-    return ary_make_partial(ary, rb_obj_class(ary), 0, RARRAY_LEN(ary));
+    return ary_make_partial(ary, rb_cArray, 0, RARRAY_LEN(ary));
 }
 
 enum ary_take_pos_flags
@@ -1149,46 +1344,47 @@ enum ary_take_pos_flags
 };
 
 static VALUE
-ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos_flags last)
+ary_take_first_or_last_n(VALUE ary, long n, enum ary_take_pos_flags last)
 {
-    long n;
-    long len;
+    long len = RARRAY_LEN(ary);
     long offset = 0;
 
-    argc = rb_check_arity(argc, 0, 1);
-    /* the case optional argument is omitted should be handled in
-     * callers of this function.  if another arity case is added,
-     * this arity check needs to rewrite. */
-    RUBY_ASSERT_ALWAYS(argc == 1);
-
-    n = NUM2LONG(argv[0]);
-    len = RARRAY_LEN(ary);
     if (n > len) {
-	n = len;
+        n = len;
     }
     else if (n < 0) {
-	rb_raise(rb_eArgError, "negative array size");
+        rb_raise(rb_eArgError, "negative array size");
     }
     if (last) {
-	offset = len - n;
+        offset = len - n;
     }
     return ary_make_partial(ary, rb_cArray, offset, n);
 }
 
+static VALUE
+ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos_flags last)
+{
+    argc = rb_check_arity(argc, 0, 1);
+    /* the case optional argument is omitted should be handled in
+     * callers of this function.  if another arity case is added,
+     * this arity check needs to rewrite. */
+    RUBY_ASSERT_ALWAYS(argc == 1);
+    return ary_take_first_or_last_n(ary, NUM2LONG(argv[0]), last);
+}
+
 /*
  *  call-seq:
- *     ary << obj            -> ary
+ *    self << object -> self
+ *
+ *  Appends +object+ as the last element in +self+; returns +self+:
  *
- *  Append---Pushes the given object on to the end of this array. This
- *  expression returns the array itself, so several appends
- *  may be chained together.
+ *    [:foo, 'bar', 2] << :baz # => [:foo, "bar", 2, :baz]
  *
- *     a = [ 1, 2 ]
- *     a << "c" << "d" << [ 3, 4 ]
- *             #=>  [ 1, 2, "c", "d", [ 3, 4 ] ]
- *     a
- *             #=>  [ 1, 2, "c", "d", [ 3, 4 ] ]
+ *  Appends +object+ as a single element, even if it is another array:
  *
+ *    [:foo, 'bar', 2] << [3, 4] # => [:foo, "bar", 2, [3, 4]]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
@@ -1196,8 +1392,8 @@ rb_ary_push(VALUE ary, VALUE item)
 {
     long idx = RARRAY_LEN((ary_verify(ary), ary));
     VALUE target_ary = ary_ensure_room_for_push(ary, 1);
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-	RB_OBJ_WRITE(target_ary, &ptr[idx], item);
+    RARRAY_PTR_USE(ary, ptr, {
+        RB_OBJ_WRITE(target_ary, &ptr[idx], item);
     });
     ARY_SET_LEN(ary, idx + 1);
     ary_verify(ary);
@@ -1216,19 +1412,20 @@ rb_ary_cat(VALUE ary, const VALUE *argv, long len)
 
 /*
  *  call-seq:
- *     ary.push(obj, ...)    -> ary
- *     ary.append(obj, ...)  -> ary
- *
- *  Append --- Pushes the given object(s) on to the end of this array. This
- *  expression returns the array itself, so several appends
- *  may be chained together. See also Array#pop for the opposite
- *  effect.
- *
- *     a = [ "a", "b", "c" ]
- *     a.push("d", "e", "f")
- *             #=> ["a", "b", "c", "d", "e", "f"]
- *     [1, 2, 3].push(4).push(5)
- *             #=> [1, 2, 3, 4, 5]
+ *    push(*objects) -> self
+ *    append(*objects) -> self
+ *
+ *  Appends each argument in +objects+ to +self+; returns +self+:
+ *
+ *    a = [:foo, 'bar', 2] # => [:foo, "bar", 2]
+ *    a.push(:baz, :bat)   # => [:foo, "bar", 2, :baz, :bat]
+ *
+ *  Appends each argument as a single element, even if it is another array:
+ *
+ *    a = [:foo, 'bar', 2]               # => [:foo, "bar", 2]
+      a.push([:baz, :bat], [:bam, :bad]) # => [:foo, "bar", 2, [:baz, :bat], [:bam, :bad]]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -1245,33 +1442,47 @@ rb_ary_pop(VALUE ary)
     n = RARRAY_LEN(ary);
     if (n == 0) return Qnil;
     if (ARY_OWNS_HEAP_P(ary) &&
-	n * 3 < ARY_CAPA(ary) &&
-	ARY_CAPA(ary) > ARY_DEFAULT_SIZE)
+        n * 3 < ARY_CAPA(ary) &&
+        ARY_CAPA(ary) > ARY_DEFAULT_SIZE)
     {
-	ary_resize_capa(ary, n * 2);
+        ary_resize_capa(ary, n * 2);
     }
-    --n;
-    ARY_SET_LEN(ary, n);
+
+    VALUE obj = RARRAY_AREF(ary, n - 1);
+
+    ARY_SET_LEN(ary, n - 1);
     ary_verify(ary);
-    return RARRAY_AREF(ary, n);
+    return obj;
 }
 
 /*
  *  call-seq:
- *     ary.pop    -> obj or nil
- *     ary.pop(n) -> new_ary
+ *    pop -> object or nil
+ *    pop(count) -> new_array
+ *
+ *  Removes and returns trailing elements of +self+.
+ *
+ *  With no argument given, removes and returns the last element, if available;
+ *  otherwise returns +nil+:
  *
- *  Removes the last element from +self+ and returns it, or
- *  +nil+ if the array is empty.
+ *    a = [:foo, 'bar', 2]
+ *    a.pop  # => 2
+ *    a      # => [:foo, "bar"]
+ *    [].pop # => nil
  *
- *  If a number +n+ is given, returns an array of the last +n+ elements
- *  (or less) just like <code>array.slice!(-n, n)</code> does. See also
- *  Array#push for the opposite effect.
+ *  With non-negative integer argument +count+ given,
+ *  returns a new array containing the trailing +count+ elements of +self+, as available:
  *
- *     a = [ "a", "b", "c", "d" ]
- *     a.pop     #=> "d"
- *     a.pop(2)  #=> ["b", "c"]
- *     a         #=> ["a"]
+ *    a = [:foo, 'bar', 2]
+ *    a.pop(2) # => ["bar", 2]
+ *    a        # => [:foo]
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.pop(50) # => [:foo, "bar", 2]
+ *    a         # => []
+ *
+ *  Related: Array#push;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -1280,7 +1491,7 @@ rb_ary_pop_m(int argc, VALUE *argv, VALUE ary)
     VALUE result;
 
     if (argc == 0) {
-	return rb_ary_pop(ary);
+        return rb_ary_pop(ary);
     }
 
     rb_ary_modify_check(ary);
@@ -1296,55 +1507,54 @@ rb_ary_shift(VALUE ary)
     VALUE top;
     long len = RARRAY_LEN(ary);
 
-    rb_ary_modify_check(ary);
-    if (len == 0) return Qnil;
-    top = RARRAY_AREF(ary, 0);
-    if (!ARY_SHARED_P(ary)) {
-	if (len < ARY_DEFAULT_SIZE) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-		MEMMOVE(ptr, ptr+1, VALUE, len-1);
-	    }); /* WB: no new reference */
-            ARY_INCREASE_LEN(ary, -1);
-            ary_verify(ary);
-	    return top;
-	}
-        assert(!ARY_EMBED_P(ary)); /* ARY_EMBED_LEN_MAX < ARY_DEFAULT_SIZE */
-
-	ARY_SET(ary, 0, Qnil);
-	ary_make_shared(ary);
-    }
-    else if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, ptr[0] = Qnil);
+    if (len == 0) {
+        rb_ary_modify_check(ary);
+        return Qnil;
     }
-    ARY_INCREASE_PTR(ary, 1);		/* shift ptr */
-    ARY_INCREASE_LEN(ary, -1);
 
-    ary_verify(ary);
+    top = RARRAY_AREF(ary, 0);
+
+    rb_ary_behead(ary, 1);
 
     return top;
 }
 
 /*
  *  call-seq:
- *     ary.shift    -> obj or nil
- *     ary.shift(n) -> new_ary
+ *    shift -> object or nil
+ *    shift(count) -> new_array or nil
+ *
+ *  Removes and returns leading elements from +self+.
+ *
+ *  With no argument, removes and returns one element, if available,
+ *  or +nil+ otherwise:
+ *
+ *    a = [0, 1, 2, 3]
+ *    a.shift  # => 0
+ *    a        # => [1, 2, 3]
+ *    [].shift # => nil
+ *
+ *  With non-negative numeric argument +count+ given,
+ *  removes and returns the first +count+ elements:
  *
- *  Removes the first element of +self+ and returns it (shifting all
- *  other elements down by one). Returns +nil+ if the array
- *  is empty.
+ *    a = [0, 1, 2, 3]
+ *    a.shift(2)   # => [0, 1]
+ *    a            # => [2, 3]
+ *    a.shift(1.1) # => [2]
+ *    a            # => [3]
+ *    a.shift(0)   # => []
+ *    a            # => [3]
  *
- *  If a number +n+ is given, returns an array of the first +n+ elements
- *  (or less) just like <code>array.slice!(0, n)</code> does. With +ary+
- *  containing only the remainder elements, not including what was shifted to
- *  +new_ary+. See also Array#unshift for the opposite effect.
+ *  If +count+ is large,
+ *  removes and returns all elements:
  *
- *     args = [ "-m", "-q", "filename" ]
- *     args.shift     #=> "-m"
- *     args           #=> ["-q", "filename"]
+ *    a = [0, 1, 2, 3]
+ *    a.shift(50) # => [0, 1, 2, 3]
+ *    a           # => []
  *
- *     args = [ "-m", "-q", "filename" ]
- *     args.shift(2)  #=> ["-m", "-q"]
- *     args           #=> ["filename"]
+ *  If +self+ is empty, returns a new empty array.
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -1354,7 +1564,7 @@ rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
     long n;
 
     if (argc == 0) {
-	return rb_ary_shift(ary);
+        return rb_ary_shift(ary);
     }
 
     rb_ary_modify_check(ary);
@@ -1365,123 +1575,147 @@ rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
     return result;
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_ary_behead(VALUE ary, long n)
 {
-    if (n<=0) return ary;
+    if (n <= 0) {
+        return ary;
+    }
 
     rb_ary_modify_check(ary);
-    if (ARY_SHARED_P(ary)) {
-        if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
-	  setup_occupied_shared:
-	    ary_mem_clear(ary, 0, n);
-	}
-        ARY_INCREASE_PTR(ary, n);
+
+    if (!ARY_SHARED_P(ary)) {
+        if (ARY_EMBED_P(ary) || RARRAY_LEN(ary) < ARY_DEFAULT_SIZE) {
+            RARRAY_PTR_USE(ary, ptr, {
+                MEMMOVE(ptr, ptr + n, VALUE, RARRAY_LEN(ary) - n);
+            }); /* WB: no new reference */
+            ARY_INCREASE_LEN(ary, -n);
+            ary_verify(ary);
+            return ary;
+        }
+
+        ary_mem_clear(ary, 0, n);
+        ary_make_shared(ary);
     }
-    else {
-	if (RARRAY_LEN(ary) < ARY_DEFAULT_SIZE) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-                MEMMOVE(ptr, ptr+n, VALUE, RARRAY_LEN(ary)-n);
-	    }); /* WB: no new reference */
-	}
-	else {
-	    ary_make_shared(ary);
-	    goto setup_occupied_shared;
-	}
+    else if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
+        ary_mem_clear(ary, 0, n);
     }
-    ARY_INCREASE_LEN(ary, -n);
 
+    ARY_INCREASE_PTR(ary, n);
+    ARY_INCREASE_LEN(ary, -n);
     ary_verify(ary);
+
     return ary;
 }
 
 static VALUE
-ary_ensure_room_for_unshift(VALUE ary, int argc)
+make_room_for_unshift(VALUE ary, const VALUE *head, VALUE *sharedp, int argc, long capa, long len)
+{
+    if (head - sharedp < argc) {
+        long room = capa - len - argc;
+
+        room -= room >> 4;
+        MEMMOVE((VALUE *)sharedp + argc + room, head, VALUE, len);
+        head = sharedp + argc + room;
+    }
+    ARY_SET_PTR(ary, head - argc);
+    RUBY_ASSERT(ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary)));
+
+    ary_verify(ary);
+    return ARY_SHARED_ROOT(ary);
+}
+
+static VALUE
+ary_modify_for_unshift(VALUE ary, int argc)
 {
     long len = RARRAY_LEN(ary);
     long new_len = len + argc;
     long capa;
     const VALUE *head, *sharedp;
 
-    if (len > ARY_MAX_SIZE - argc) {
-	rb_raise(rb_eIndexError, "index %ld too big", new_len);
-    }
-
-    if (ARY_SHARED_P(ary)) {
-        VALUE shared_root = ARY_SHARED_ROOT(ary);
-        capa = RARRAY_LEN(shared_root);
-        if (ARY_SHARED_ROOT_OCCUPIED(shared_root) && capa > new_len) {
-            rb_ary_modify_check(ary);
-            head = RARRAY_CONST_PTR_TRANSIENT(ary);
-            sharedp = RARRAY_CONST_PTR_TRANSIENT(shared_root);
-	    goto makeroom_if_need;
-	}
-    }
-
     rb_ary_modify(ary);
     capa = ARY_CAPA(ary);
     if (capa - (capa >> 6) <= new_len) {
-	ary_double_capa(ary, new_len);
+        ary_double_capa(ary, new_len);
     }
 
     /* use shared array for big "queues" */
-    if (new_len > ARY_DEFAULT_SIZE * 4) {
+    if (new_len > ARY_DEFAULT_SIZE * 4 && !ARY_EMBED_P(ary)) {
         ary_verify(ary);
 
         /* make a room for unshifted items */
-	capa = ARY_CAPA(ary);
-	ary_make_shared(ary);
-
-        head = sharedp = RARRAY_CONST_PTR_TRANSIENT(ary);
-	goto makeroom;
-      makeroom_if_need:
-	if (head - sharedp < argc) {
-	    long room;
-	  makeroom:
-	    room = capa - new_len;
-	    room -= room >> 4;
-	    MEMMOVE((VALUE *)sharedp + argc + room, head, VALUE, len);
-	    head = sharedp + argc + room;
-	}
-	ARY_SET_PTR(ary, head - argc);
-        assert(ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary)));
+        capa = ARY_CAPA(ary);
+        ary_make_shared(ary);
 
-        ary_verify(ary);
-        return ARY_SHARED_ROOT(ary);
+        head = sharedp = RARRAY_CONST_PTR(ary);
+        return make_room_for_unshift(ary, head, (void *)sharedp, argc, capa, len);
     }
     else {
-	/* sliding items */
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-	    MEMMOVE(ptr + argc, ptr, VALUE, len);
-	});
+        /* sliding items */
+        RARRAY_PTR_USE(ary, ptr, {
+            MEMMOVE(ptr + argc, ptr, VALUE, len);
+        });
 
         ary_verify(ary);
-	return ary;
+        return ary;
+    }
+}
+
+static VALUE
+ary_ensure_room_for_unshift(VALUE ary, int argc)
+{
+    long len = RARRAY_LEN(ary);
+    long new_len = len + argc;
+
+    if (len > ARY_MAX_SIZE - argc) {
+        rb_raise(rb_eIndexError, "index %ld too big", new_len);
+    }
+    else if (! ARY_SHARED_P(ary)) {
+        return ary_modify_for_unshift(ary, argc);
+    }
+    else {
+        VALUE shared_root = ARY_SHARED_ROOT(ary);
+        long capa = RARRAY_LEN(shared_root);
+
+        if (! ARY_SHARED_ROOT_OCCUPIED(shared_root)) {
+            return ary_modify_for_unshift(ary, argc);
+        }
+        else if (new_len > capa) {
+            return ary_modify_for_unshift(ary, argc);
+        }
+        else {
+            const VALUE * head = RARRAY_CONST_PTR(ary);
+            void *sharedp = (void *)RARRAY_CONST_PTR(shared_root);
+
+            rb_ary_modify_check(ary);
+            return make_room_for_unshift(ary, head, sharedp, argc, capa, len);
+        }
     }
 }
 
 /*
  *  call-seq:
- *     ary.unshift(obj, ...)  -> ary
- *     ary.prepend(obj, ...)  -> ary
+ *    unshift(*objects) -> self
+ *    prepend(*objects) -> self
  *
- *  Prepends objects to the front of +self+, moving other elements upwards.
- *  See also Array#shift for the opposite effect.
+ *  Prepends the given +objects+ to +self+:
  *
- *     a = [ "b", "c", "d" ]
- *     a.unshift("a")   #=> ["a", "b", "c", "d"]
- *     a.unshift(1, 2)  #=> [ 1, 2, "a", "b", "c", "d"]
+ *    a = [:foo, 'bar', 2]
+ *    a.unshift(:bam, :bat) # => [:bam, :bat, :foo, "bar", 2]
+ *
+ *  Related: Array#shift;
+ *  see also {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
-static VALUE
+VALUE
 rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
 {
     long len = RARRAY_LEN(ary);
     VALUE target_ary;
 
     if (argc == 0) {
-	rb_ary_modify_check(ary);
-	return ary;
+        rb_ary_modify_check(ary);
+        return ary;
     }
 
     target_ary = ary_ensure_room_for_unshift(ary, argc);
@@ -1493,7 +1727,7 @@ rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
 VALUE
 rb_ary_unshift(VALUE ary, VALUE item)
 {
-    return rb_ary_unshift_m(1,&item,ary);
+    return rb_ary_unshift_m(1, &item, ary);
 }
 
 /* faster version - use this if you don't need to treat negative offset */
@@ -1503,7 +1737,7 @@ rb_ary_elt(VALUE ary, long offset)
     long len = RARRAY_LEN(ary);
     if (len == 0) return Qnil;
     if (offset < 0 || len <= offset) {
-	return Qnil;
+        return Qnil;
     }
     return RARRAY_AREF(ary, offset);
 }
@@ -1515,7 +1749,7 @@ rb_ary_entry(VALUE ary, long offset)
 }
 
 VALUE
-rb_ary_subseq(VALUE ary, long beg, long len)
+rb_ary_subseq_step(VALUE ary, long beg, long len, long step)
 {
     VALUE klass;
     long alen = RARRAY_LEN(ary);
@@ -1524,48 +1758,142 @@ rb_ary_subseq(VALUE ary, long beg, long len)
     if (beg < 0 || len < 0) return Qnil;
 
     if (alen < len || alen < beg + len) {
-	len = alen - beg;
+        len = alen - beg;
     }
-    klass = rb_obj_class(ary);
+    klass = rb_cArray;
     if (len == 0) return ary_new(klass, 0);
+    if (step == 0)
+        rb_raise(rb_eArgError, "slice step cannot be zero");
+    if (step == 1)
+        return ary_make_partial(ary, klass, beg, len);
+    else
+        return ary_make_partial_step(ary, klass, beg, len, step);
+}
 
-    return ary_make_partial(ary, klass, beg, len);
+VALUE
+rb_ary_subseq(VALUE ary, long beg, long len)
+{
+    return rb_ary_subseq_step(ary, beg, len, 1);
 }
 
+static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
+
 /*
  *  call-seq:
- *     ary[index]                -> obj     or nil
- *     ary[start, length]        -> new_ary or nil
- *     ary[range]                -> new_ary or nil
- *     ary.slice(index)          -> obj     or nil
- *     ary.slice(start, length)  -> new_ary or nil
- *     ary.slice(range)          -> new_ary or nil
- *
- *  Element Reference --- Returns the element at +index+, or returns a
- *  subarray starting at the +start+ index and continuing for +length+
- *  elements, or returns a subarray specified by +range+ of indices.
- *
- *  Negative indices count backward from the end of the array (-1 is the last
- *  element).  For +start+ and +range+ cases the starting index is just before
- *  an element.  Additionally, an empty array is returned when the starting
- *  index for an element range is at the end of the array.
- *
- *  Returns +nil+ if the index (or starting index) are out of range.
- *
- *     a = [ "a", "b", "c", "d", "e" ]
- *     a[2] +  a[0] + a[1]    #=> "cab"
- *     a[6]                   #=> nil
- *     a[1, 2]                #=> [ "b", "c" ]
- *     a[1..3]                #=> [ "b", "c", "d" ]
- *     a[4..7]                #=> [ "e" ]
- *     a[6..10]               #=> nil
- *     a[-3, 3]               #=> [ "c", "d", "e" ]
- *     # special cases
- *     a[5]                   #=> nil
- *     a[6, 1]                #=> nil
- *     a[5, 1]                #=> []
- *     a[5..10]               #=> []
+ *    self[offset] -> object or nil
+ *    self[offset, size] -> object or nil
+ *    self[range] -> object or nil
+ *    self[aseq] -> object or nil
+ *
+ *  Returns elements from +self+; does not modify +self+.
+ *
+ *  In brief:
+ *
+ *    a = [:foo, 'bar', 2]
+ *
+ *    # Single argument offset: returns one element.
+ *    a[0]     # => :foo          # Zero-based index.
+ *    a[-1]    # => 2             # Negative index counts backwards from end.
+ *
+ *    # Arguments offset and size: returns an array.
+ *    a[1, 2]  # => ["bar", 2]
+ *    a[-2, 2] # => ["bar", 2]    # Negative offset counts backwards from end.
+ *
+ *    # Single argument range: returns an array.
+ *    a[0..1]  # => [:foo, "bar"]
+ *    a[0..-2] # => [:foo, "bar"] # Negative range-begin counts backwards from end.
+ *    a[-2..2] # => ["bar", 2]    # Negative range-end counts backwards from end.
+ *
+ *  When a single integer argument +offset+ is given, returns the element at offset +offset+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0] # => :foo
+ *    a[2] # => 2
+ *    a # => [:foo, "bar", 2]
+ *
+ *  If +offset+ is negative, counts backwards from the end of +self+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[-1] # => 2
+ *    a[-2] # => "bar"
+ *
+ *  If +index+ is out of range, returns +nil+.
+ *
+ *  When two Integer arguments +offset+ and +size+ are given,
+ *  returns a new array of size +size+ containing successive elements beginning at offset +offset+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0, 2] # => [:foo, "bar"]
+ *    a[1, 2] # => ["bar", 2]
+ *
+ *  If <tt>offset + size</tt> is greater than <tt>self.size</tt>,
+ *  returns all elements from offset +offset+ to the end:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0, 4] # => [:foo, "bar", 2]
+ *    a[1, 3] # => ["bar", 2]
+ *    a[2, 2] # => [2]
+ *
+ *  If <tt>offset == self.size</tt> and <tt>size >= 0</tt>,
+ *  returns a new empty array.
+ *
+ *  If +size+ is negative, returns +nil+.
+ *
+ *  When a single Range argument +range+ is given,
+ *  treats <tt>range.min</tt> as +offset+ above
+ *  and <tt>range.size</tt> as +size+ above:
  *
+ *    a = [:foo, 'bar', 2]
+ *    a[0..1] # => [:foo, "bar"]
+ *    a[1..2] # => ["bar", 2]
+ *
+ *  Special case: If <tt>range.start == a.size</tt>, returns a new empty array.
+ *
+ *  If <tt>range.end</tt> is negative, calculates the end index from the end:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0..-1] # => [:foo, "bar", 2]
+ *    a[0..-2] # => [:foo, "bar"]
+ *    a[0..-3] # => [:foo]
+ *
+ *  If <tt>range.start</tt> is negative, calculates the start index from the end:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[-1..2] # => [2]
+ *    a[-2..2] # => ["bar", 2]
+ *    a[-3..2] # => [:foo, "bar", 2]
+ *
+ *  If <tt>range.start</tt> is larger than the array size, returns +nil+.
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[4..1] # => nil
+ *    a[4..0] # => nil
+ *    a[4..-1] # => nil
+ *
+ *  When a single Enumerator::ArithmeticSequence argument +aseq+ is given,
+ *  returns an array of elements corresponding to the indexes produced by
+ *  the sequence.
+ *
+ *    a = ['--', 'data1', '--', 'data2', '--', 'data3']
+ *    a[(1..).step(2)] # => ["data1", "data2", "data3"]
+ *
+ *  Unlike slicing with range, if the start or the end of the arithmetic sequence
+ *  is larger than array size, throws RangeError.
+ *
+ *    a = ['--', 'data1', '--', 'data2', '--', 'data3']
+ *    a[(1..11).step(2)]
+ *    # RangeError (((1..11).step(2)) out of range)
+ *    a[(7..).step(2)]
+ *    # RangeError (((7..).step(2)) out of range)
+ *
+ *  If given a single argument, and its type is not one of the listed, tries to
+ *  convert it to Integer, and raises if it is impossible:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    # Raises TypeError (no implicit conversion of Symbol into Integer):
+ *    a[:foo]
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -1573,54 +1901,66 @@ rb_ary_aref(int argc, const VALUE *argv, VALUE ary)
 {
     rb_check_arity(argc, 1, 2);
     if (argc == 2) {
-	return rb_ary_aref2(ary, argv[0], argv[1]);
+        return rb_ary_aref2(ary, argv[0], argv[1]);
     }
     return rb_ary_aref1(ary, argv[0]);
 }
 
-VALUE
+static VALUE
 rb_ary_aref2(VALUE ary, VALUE b, VALUE e)
 {
     long beg = NUM2LONG(b);
     long len = NUM2LONG(e);
     if (beg < 0) {
-	beg += RARRAY_LEN(ary);
+        beg += RARRAY_LEN(ary);
     }
     return rb_ary_subseq(ary, beg, len);
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_ary_aref1(VALUE ary, VALUE arg)
 {
-    long beg, len;
+    long beg, len, step;
 
     /* special case - speeding up */
     if (FIXNUM_P(arg)) {
-	return rb_ary_entry(ary, FIX2LONG(arg));
+        return rb_ary_entry(ary, FIX2LONG(arg));
     }
-    /* check if idx is Range */
-    switch (rb_range_beg_len(arg, &beg, &len, RARRAY_LEN(ary), 0)) {
+    /* check if idx is Range or ArithmeticSequence */
+    switch (rb_arithmetic_sequence_beg_len_step(arg, &beg, &len, &step, RARRAY_LEN(ary), 0)) {
       case Qfalse:
-	break;
+        break;
       case Qnil:
-	return Qnil;
+        return Qnil;
       default:
-	return rb_ary_subseq(ary, beg, len);
+        return rb_ary_subseq_step(ary, beg, len, step);
     }
+
     return rb_ary_entry(ary, NUM2LONG(arg));
 }
 
 /*
  *  call-seq:
- *     ary.at(index)   ->   obj  or nil
+ *    at(index) -> object or nil
+ *
+ *  Returns the element of +self+ specified by the given +index+
+ *  or +nil+ if there is no such element;
+ *  +index+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
+ *
+ *  For non-negative +index+, returns the element of +self+ at offset +index+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.at(0)   # => :foo
+ *    a.at(2)   # => 2
+ *    a.at(2.0) # => 2
  *
- *  Returns the element at +index+. A negative index counts from the end of
- *  +self+. Returns +nil+ if the index is out of range. See also
- *  Array#[].
+ *  For negative +index+, counts backwards from the end of +self+:
  *
- *     a = [ "a", "b", "c", "d", "e" ]
- *     a.at(0)     #=> "a"
- *     a.at(-1)    #=> "e"
+ *    a.at(-2) # => "bar"
+ *
+ *  Related: Array#[];
+ *  see also {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -1629,83 +1969,82 @@ rb_ary_at(VALUE ary, VALUE pos)
     return rb_ary_entry(ary, NUM2LONG(pos));
 }
 
-/*
- *  call-seq:
- *     ary.first     ->   obj or nil
- *     ary.first(n)  ->   new_ary
- *
- *  Returns the first element, or the first +n+ elements, of the array.
- *  If the array is empty, the first form returns +nil+, and the
- *  second form returns an empty array. See also Array#last for
- *  the opposite effect.
- *
- *     a = [ "q", "r", "s", "t" ]
- *     a.first     #=> "q"
- *     a.first(2)  #=> ["q", "r"]
- */
-
+#if 0
 static VALUE
 rb_ary_first(int argc, VALUE *argv, VALUE ary)
 {
     if (argc == 0) {
-	if (RARRAY_LEN(ary) == 0) return Qnil;
-	return RARRAY_AREF(ary, 0);
+        if (RARRAY_LEN(ary) == 0) return Qnil;
+        return RARRAY_AREF(ary, 0);
     }
     else {
-	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
+        return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
     }
 }
+#endif
 
-/*
- *  call-seq:
- *     ary.last     ->  obj or nil
- *     ary.last(n)  ->  new_ary
- *
- *  Returns the last element(s) of +self+. If the array is empty,
- *  the first form returns +nil+.
- *
- *  See also Array#first for the opposite effect.
- *
- *     a = [ "w", "x", "y", "z" ]
- *     a.last     #=> "z"
- *     a.last(2)  #=> ["y", "z"]
- */
+static VALUE
+ary_first(VALUE self)
+{
+    return (RARRAY_LEN(self) == 0) ? Qnil : RARRAY_AREF(self, 0);
+}
+
+static VALUE
+ary_last(VALUE self)
+{
+    long len = RARRAY_LEN(self);
+    return (len == 0) ? Qnil : RARRAY_AREF(self, len-1);
+}
 
 VALUE
-rb_ary_last(int argc, const VALUE *argv, VALUE ary)
+rb_ary_last(int argc, const VALUE *argv, VALUE ary) // used by parse.y
 {
     if (argc == 0) {
-	long len = RARRAY_LEN(ary);
-	if (len == 0) return Qnil;
-	return RARRAY_AREF(ary, len-1);
+        return ary_last(ary);
     }
     else {
-	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
+        return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
     }
 }
 
 /*
  *  call-seq:
- *     ary.fetch(index)                    -> obj
- *     ary.fetch(index, default)           -> obj
- *     ary.fetch(index) {|index| block}    -> obj
- *
- *  Tries to return the element at position +index+, but throws an IndexError
- *  exception if the referenced +index+ lies outside of the array bounds.  This
- *  error can be prevented by supplying a second argument, which will act as a
- *  +default+ value.
- *
- *  Alternatively, if a block is given it will only be executed when an
- *  invalid +index+ is referenced.
- *
- *  Negative values of +index+ count from the end of the array.
- *
- *     a = [ 11, 22, 33, 44 ]
- *     a.fetch(1)               #=> 22
- *     a.fetch(-1)              #=> 44
- *     a.fetch(4, 'cat')        #=> "cat"
- *     a.fetch(100) {|i| puts "#{i} is out of bounds"}
- *                              #=> "100 is out of bounds"
+ *    fetch(index) -> element
+ *    fetch(index, default_value) -> element or default_value
+ *    fetch(index) {|index| ... } -> element or block_return_value
+ *
+ *  Returns the element of +self+ at offset +index+ if +index+ is in range; +index+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
+ *
+ *  With the single argument +index+ and no block,
+ *  returns the element at offset +index+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(1)   # => "bar"
+ *    a.fetch(1.1) # => "bar"
+ *
+ *  If +index+ is negative, counts from the end of the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(-1) # => 2
+ *    a.fetch(-2) # => "bar"
+ *
+ *  With arguments +index+ and +default_value+ (which may be any object) and no block,
+ *  returns +default_value+ if +index+ is out-of-range:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(1, nil)  # => "bar"
+ *    a.fetch(3, :foo) # => :foo
+ *
+ *  With argument +index+ and a block,
+ *  returns the element at offset +index+ if index is in range
+ *  (and the block is not called); otherwise calls the block with index and returns its return value:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(1) {|index| raise 'Cannot happen' } # => "bar"
+ *    a.fetch(50) {|index| "Value for #{index}" } # => "Value for 50"
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -1718,48 +2057,145 @@ rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
     rb_scan_args(argc, argv, "11", &pos, &ifnone);
     block_given = rb_block_given_p();
     if (block_given && argc == 2) {
-	rb_warn("block supersedes default value argument");
+        rb_warn("block supersedes default value argument");
     }
     idx = NUM2LONG(pos);
 
     if (idx < 0) {
-	idx +=  RARRAY_LEN(ary);
+        idx +=  RARRAY_LEN(ary);
     }
     if (idx < 0 || RARRAY_LEN(ary) <= idx) {
-	if (block_given) return rb_yield(pos);
-	if (argc == 1) {
-	    rb_raise(rb_eIndexError, "index %ld outside of array bounds: %ld...%ld",
-			idx - (idx < 0 ? RARRAY_LEN(ary) : 0), -RARRAY_LEN(ary), RARRAY_LEN(ary));
-	}
-	return ifnone;
+        if (block_given) return rb_yield(pos);
+        if (argc == 1) {
+            rb_raise(rb_eIndexError, "index %ld outside of array bounds: %ld...%ld",
+                        idx - (idx < 0 ? RARRAY_LEN(ary) : 0), -RARRAY_LEN(ary), RARRAY_LEN(ary));
+        }
+        return ifnone;
     }
     return RARRAY_AREF(ary, idx);
 }
 
 /*
+ * call-seq:
+ *   find(if_none_proc = nil) {|element| ... } -> object or nil
+ *   find(if_none_proc = nil) -> enumerator
+ *
+ * Returns the first element for which the block returns a truthy value.
+ *
+ * With a block given, calls the block with successive elements of the array;
+ * returns the first element for which the block returns a truthy value:
+ *
+ *   [1, 3, 5].find {|element| element > 2}                # => 3
+ *
+ * If no such element is found, calls +if_none_proc+ and returns its return value.
+ *
+ *   [1, 3, 5].find(proc {-1}) {|element| element > 12} # => -1
+ *
+ * With no block given, returns an Enumerator.
+ *
+ */
+
+static VALUE
+rb_ary_find(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE if_none;
+    long idx;
+
+    RETURN_ENUMERATOR(ary, argc, argv);
+    if_none = rb_check_arity(argc, 0, 1) ? argv[0] : Qnil;
+
+    for (idx = 0; idx < RARRAY_LEN(ary); idx++) {
+        VALUE elem = RARRAY_AREF(ary, idx);
+        if (RTEST(rb_yield(elem))) {
+            return elem;
+        }
+    }
+
+    if (!NIL_P(if_none)) {
+        return rb_funcallv(if_none, idCall, 0, 0);
+    }
+    return Qnil;
+}
+
+/*
+ * call-seq:
+ *   rfind(if_none_proc = nil) {|element| ... } -> object or nil
+ *   rfind(if_none_proc = nil) -> enumerator
+ *
+ * Returns the last element for which the block returns a truthy value.
+ *
+ * With a block given, calls the block with successive elements of the array in
+ * reverse order; returns the first element for which the block returns a truthy
+ * value:
+ *
+ *   [1, 2, 3, 4, 5, 6].rfind {|element| element < 5}       # => 4
+ *
+ * If no such element is found, calls +if_none_proc+ and returns its return value.
+ *
+ *   [1, 2, 3, 4].rfind(proc {0}) {|element| element < -2}  # => 0
+ *
+ * With no block given, returns an Enumerator.
+ *
+ */
+
+static VALUE
+rb_ary_rfind(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE if_none;
+    long len, idx;
+
+    RETURN_ENUMERATOR(ary, argc, argv);
+    if_none = rb_check_arity(argc, 0, 1) ? argv[0] : Qnil;
+
+    idx = RARRAY_LEN(ary);
+    while (idx--) {
+        VALUE elem = RARRAY_AREF(ary, idx);
+        if (RTEST(rb_yield(elem))) {
+            return elem;
+        }
+
+        len = RARRAY_LEN(ary);
+        idx = (idx >= len) ? len : idx;
+    }
+
+    if (!NIL_P(if_none)) {
+        return rb_funcallv(if_none, idCall, 0, 0);
+    }
+    return Qnil;
+}
+
+/*
  *  call-seq:
- *     ary.find_index(obj)             ->  int or nil
- *     ary.find_index {|item| block}  ->  int or nil
- *     ary.find_index                  ->  Enumerator
- *     ary.index(obj)             ->  int or nil
- *     ary.index {|item| block}   ->  int or nil
- *     ary.index                  ->  Enumerator
+ *    find_index(object) -> integer or nil
+ *    find_index {|element| ... } -> integer or nil
+ *    find_index -> new_enumerator
+ *    index(object) -> integer or nil
+ *    index {|element| ... } -> integer or nil
+ *    index -> new_enumerator
+ *
+ *  Returns the zero-based integer index of a specified element, or +nil+.
+ *
+ *  With only argument +object+ given,
+ *  returns the index of the first element +element+
+ *  for which <tt>object == element</tt>:
+ *
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.index('bar') # => 1
+ *
+ *  Returns +nil+ if no such element found.
  *
- *  Returns the _index_ of the first object in +ary+ such that the object is
- *  <code>==</code> to +obj+.
+ *  With only a block given,
+ *  calls the block with each successive element;
+ *  returns the index of the first element for which the block returns a truthy value:
  *
- *  If a block is given instead of an argument, returns the _index_ of the
- *  first object for which the block returns +true+.  Returns +nil+ if no
- *  match is found.
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.index {|element| element == 'bar' } # => 1
  *
- *  See also Array#rindex.
+ *  Returns +nil+ if the block never returns a truthy value.
  *
- *  An Enumerator is returned if neither a block nor argument is given.
+ *  With neither an argument nor a block given, returns a new Enumerator.
  *
- *     a = [ "a", "b", "c" ]
- *     a.index("b")              #=> 1
- *     a.index("z")              #=> nil
- *     a.index {|x| x == "b"}    #=> 1
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -1769,49 +2205,53 @@ rb_ary_index(int argc, VALUE *argv, VALUE ary)
     long i;
 
     if (argc == 0) {
-	RETURN_ENUMERATOR(ary, 0, 0);
-	for (i=0; i<RARRAY_LEN(ary); i++) {
-	    if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
-		return LONG2NUM(i);
-	    }
-	}
-	return Qnil;
+        RETURN_ENUMERATOR(ary, 0, 0);
+        for (i=0; i<RARRAY_LEN(ary); i++) {
+            if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
+                return LONG2NUM(i);
+            }
+        }
+        return Qnil;
     }
     rb_check_arity(argc, 0, 1);
     val = argv[0];
     if (rb_block_given_p())
-	rb_warn("given block not used");
+        rb_warn("given block not used");
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	VALUE e = RARRAY_AREF(ary, i);
-	if (rb_equal(e, val)) {
-	    return LONG2NUM(i);
-	}
+        VALUE e = RARRAY_AREF(ary, i);
+        if (rb_equal(e, val)) {
+            return LONG2NUM(i);
+        }
     }
     return Qnil;
 }
 
 /*
  *  call-seq:
- *     ary.rindex(obj)             ->  int or nil
- *     ary.rindex {|item| block}   ->  int or nil
- *     ary.rindex                  ->  Enumerator
+ *    rindex(object) -> integer or nil
+ *    rindex {|element| ... } -> integer or nil
+ *    rindex -> new_enumerator
  *
- *  Returns the _index_ of the last object in +self+ <code>==</code> to +obj+.
+ *  Returns the index of the last element for which <tt>object == element</tt>.
  *
- *  If a block is given instead of an argument, returns the _index_ of the
- *  first object for which the block returns +true+, starting from the last
- *  object.
+ *  With argument +object+ given, returns the index of the last such element found:
  *
- *  Returns +nil+ if no match is found.
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.rindex('bar') # => 3
  *
- *  See also Array#index.
+ *  Returns +nil+ if no such object found.
  *
- *  If neither block nor argument is given, an Enumerator is returned instead.
+ *  With a block given, calls the block with each successive element;
+ *  returns the index of the last element for which the block returns a truthy value:
  *
- *     a = [ "a", "b", "b", "b", "c" ]
- *     a.rindex("b")             #=> 3
- *     a.rindex("z")             #=> nil
- *     a.rindex {|x| x == "b"}   #=> 3
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.rindex {|element| element == 'bar' } # => 3
+ *
+ *  Returns +nil+ if the block never returns a truthy value.
+ *
+ *  When neither an argument nor a block is given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -1821,25 +2261,25 @@ rb_ary_rindex(int argc, VALUE *argv, VALUE ary)
     long i = RARRAY_LEN(ary), len;
 
     if (argc == 0) {
-	RETURN_ENUMERATOR(ary, 0, 0);
-	while (i--) {
-	    if (RTEST(rb_yield(RARRAY_AREF(ary, i))))
-		return LONG2NUM(i);
-	    if (i > (len = RARRAY_LEN(ary))) {
-		i = len;
-	    }
-	}
-	return Qnil;
+        RETURN_ENUMERATOR(ary, 0, 0);
+        while (i--) {
+            if (RTEST(rb_yield(RARRAY_AREF(ary, i))))
+                return LONG2NUM(i);
+            if (i > (len = RARRAY_LEN(ary))) {
+                i = len;
+            }
+        }
+        return Qnil;
     }
     rb_check_arity(argc, 0, 1);
     val = argv[0];
     if (rb_block_given_p())
-	rb_warn("given block not used");
+        rb_warn("given block not used");
     while (i--) {
-	VALUE e = RARRAY_AREF(ary, i);
-	if (rb_equal(e, val)) {
-	    return LONG2NUM(i);
-	}
+        VALUE e = RARRAY_AREF(ary, i);
+        if (rb_equal(e, val)) {
+            return LONG2NUM(i);
+        }
         if (i > RARRAY_LEN(ary)) {
             break;
         }
@@ -1865,64 +2305,69 @@ rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
     if (len < 0) rb_raise(rb_eIndexError, "negative length (%ld)", len);
     olen = RARRAY_LEN(ary);
     if (beg < 0) {
-	beg += olen;
-	if (beg < 0) {
-	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
-		     beg - olen, -olen);
-	}
+        beg += olen;
+        if (beg < 0) {
+            rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+                     beg - olen, -olen);
+        }
     }
     if (olen < len || olen < beg + len) {
-	len = olen - beg;
+        len = olen - beg;
     }
 
     {
-        const VALUE *optr = RARRAY_CONST_PTR_TRANSIENT(ary);
-	rofs = (rptr >= optr && rptr < optr + olen) ? rptr - optr : -1;
+        const VALUE *optr = RARRAY_CONST_PTR(ary);
+        rofs = (rptr >= optr && rptr < optr + olen) ? rptr - optr : -1;
     }
 
     if (beg >= olen) {
-	VALUE target_ary;
-	if (beg > ARY_MAX_SIZE - rlen) {
-	    rb_raise(rb_eIndexError, "index %ld too big", beg);
-	}
-	target_ary = ary_ensure_room_for_push(ary, rlen-len); /* len is 0 or negative */
-	len = beg + rlen;
-	ary_mem_clear(ary, olen, beg - olen);
-	if (rlen > 0) {
-            if (rofs != -1) rptr = RARRAY_CONST_PTR_TRANSIENT(ary) + rofs;
-	    ary_memcpy0(ary, beg, rlen, rptr, target_ary);
-	}
-	ARY_SET_LEN(ary, len);
+        VALUE target_ary;
+        if (beg > ARY_MAX_SIZE - rlen) {
+            rb_raise(rb_eIndexError, "index %ld too big", beg);
+        }
+        target_ary = ary_ensure_room_for_push(ary, rlen-len); /* len is 0 or negative */
+        len = beg + rlen;
+        ary_mem_clear(ary, olen, beg - olen);
+        if (rlen > 0) {
+            if (rofs != -1) rptr = RARRAY_CONST_PTR(ary) + rofs;
+            ary_memcpy0(ary, beg, rlen, rptr, target_ary);
+        }
+        ARY_SET_LEN(ary, len);
     }
     else {
-	long alen;
-
-	if (olen - len > ARY_MAX_SIZE - rlen) {
-	    rb_raise(rb_eIndexError, "index %ld too big", olen + rlen - len);
-	}
-	rb_ary_modify(ary);
-	alen = olen + rlen - len;
-	if (alen >= ARY_CAPA(ary)) {
-	    ary_double_capa(ary, alen);
-	}
-
-	if (len != rlen) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr,
+        long alen;
+
+        if (olen - len > ARY_MAX_SIZE - rlen) {
+            rb_raise(rb_eIndexError, "index %ld too big", olen + rlen - len);
+        }
+        rb_ary_modify(ary);
+        alen = olen + rlen - len;
+        if (alen >= ARY_CAPA(ary)) {
+            ary_double_capa(ary, alen);
+        }
+
+        if (len != rlen) {
+            RARRAY_PTR_USE(ary, ptr,
                                      MEMMOVE(ptr + beg + rlen, ptr + beg + len,
                                              VALUE, olen - (beg + len)));
-	    ARY_SET_LEN(ary, alen);
-	}
-	if (rlen > 0) {
-            if (rofs != -1) rptr = RARRAY_CONST_PTR_TRANSIENT(ary) + rofs;
-            /* give up wb-protected ary */
-            RB_OBJ_WB_UNPROTECT_FOR(ARRAY, ary);
+            ARY_SET_LEN(ary, alen);
+        }
+        if (rlen > 0) {
+            if (rofs == -1) {
+                rb_gc_writebarrier_remember(ary);
+            }
+            else {
+                /* In this case, we're copying from a region in this array, so
+                 * we don't need to fire the write barrier. */
+                rptr = RARRAY_CONST_PTR(ary) + rofs;
+            }
 
             /* do not use RARRAY_PTR() because it can causes GC.
              * ary can contain T_NONE object because it is not cleared.
              */
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr,
+            RARRAY_PTR_USE(ary, ptr,
                                      MEMMOVE(ptr + beg, rptr, VALUE, rlen));
-	}
+        }
     }
 }
 
@@ -1933,22 +2378,14 @@ rb_ary_set_len(VALUE ary, long len)
 
     rb_ary_modify_check(ary);
     if (ARY_SHARED_P(ary)) {
-	rb_raise(rb_eRuntimeError, "can't set length of shared ");
+        rb_raise(rb_eRuntimeError, "can't set length of shared ");
     }
     if (len > (capa = (long)ARY_CAPA(ary))) {
-	rb_bug("probable buffer overflow: %ld for %ld", len, capa);
+        rb_bug("probable buffer overflow: %ld for %ld", len, capa);
     }
     ARY_SET_LEN(ary, len);
 }
 
-/*!
- * expands or shrinks \a ary to \a len elements.
- * expanded region will be filled with Qnil.
- * \param ary  an array
- * \param len  new size
- * \return     \a ary
- * \post       the size of \a ary is \a len.
- */
 VALUE
 rb_ary_resize(VALUE ary, long len)
 {
@@ -1958,118 +2395,260 @@ rb_ary_resize(VALUE ary, long len)
     olen = RARRAY_LEN(ary);
     if (len == olen) return ary;
     if (len > ARY_MAX_SIZE) {
-	rb_raise(rb_eIndexError, "index %ld too big", len);
+        rb_raise(rb_eIndexError, "index %ld too big", len);
     }
     if (len > olen) {
-	if (len >= ARY_CAPA(ary)) {
-	    ary_double_capa(ary, len);
-	}
-	ary_mem_clear(ary, olen, len - olen);
-	ARY_SET_LEN(ary, len);
+        if (len > ARY_CAPA(ary)) {
+            ary_double_capa(ary, len);
+        }
+        ary_mem_clear(ary, olen, len - olen);
+        ARY_SET_LEN(ary, len);
     }
     else if (ARY_EMBED_P(ary)) {
         ARY_SET_EMBED_LEN(ary, len);
     }
-    else if (len <= RARRAY_EMBED_LEN_MAX) {
-	VALUE tmp[RARRAY_EMBED_LEN_MAX];
-	MEMCPY(tmp, ARY_HEAP_PTR(ary), VALUE, len);
-	ary_discard(ary);
-	MEMCPY((VALUE *)ARY_EMBED_PTR(ary), tmp, VALUE, len); /* WB: no new reference */
+    else if (len <= ary_embed_capa(ary)) {
+        const VALUE *ptr = ARY_HEAP_PTR(ary);
+        long ptr_capa = ARY_HEAP_SIZE(ary);
+        bool is_malloc_ptr = !ARY_SHARED_P(ary);
+
+        FL_SET_EMBED(ary);
+
+        MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len); /* WB: no new reference */
         ARY_SET_EMBED_LEN(ary, len);
+
+        if (is_malloc_ptr) ruby_xfree_sized((void *)ptr, ptr_capa);
     }
     else {
-	if (olen > len + ARY_DEFAULT_SIZE) {
-            ary_heap_realloc(ary, len);
-	    ARY_SET_CAPA(ary, len);
-	}
-	ARY_SET_HEAP_LEN(ary, len);
+        if (olen > len + ARY_DEFAULT_SIZE) {
+            size_t new_capa = ary_heap_realloc(ary, len);
+            ARY_SET_CAPA(ary, new_capa);
+        }
+        ARY_SET_HEAP_LEN(ary, len);
     }
     ary_verify(ary);
     return ary;
 }
 
+static VALUE
+ary_aset_by_rb_ary_store(VALUE ary, long key, VALUE val)
+{
+    rb_ary_store(ary, key, val);
+    return val;
+}
+
+static VALUE
+ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
+{
+    VALUE rpl = rb_ary_to_ary(val);
+    rb_ary_splice(ary, beg, len, RARRAY_CONST_PTR(rpl), RARRAY_LEN(rpl));
+    RB_GC_GUARD(rpl);
+    return val;
+}
+
 /*
  *  call-seq:
- *     ary[index]         = obj                      ->  obj
- *     ary[start, length] = obj or other_ary or nil  ->  obj or other_ary or nil
- *     ary[range]         = obj or other_ary or nil  ->  obj or other_ary or nil
- *
- *  Element Assignment --- Sets the element at +index+, or replaces a subarray
- *  from the +start+ index for +length+ elements, or replaces a subarray
- *  specified by the +range+ of indices.
- *
- *  If indices are greater than the current capacity of the array, the array
- *  grows automatically.  Elements are inserted into the array at +start+ if
- *  +length+ is zero.
- *
- *  Negative indices will count backward from the end of the array.  For
- *  +start+ and +range+ cases the starting index is just before an element.
- *
- *  An IndexError is raised if a negative index points past the beginning of
- *  the array.
- *
- *  See also Array#push, and Array#unshift.
- *
- *     a = Array.new
- *     a[4] = "4";                 #=> [nil, nil, nil, nil, "4"]
- *     a[0, 3] = [ 'a', 'b', 'c' ] #=> ["a", "b", "c", nil, "4"]
- *     a[1..2] = [ 1, 2 ]          #=> ["a", 1, 2, nil, "4"]
- *     a[0, 2] = "?"               #=> ["?", 2, nil, "4"]
- *     a[0..2] = "A"               #=> ["A", "4"]
- *     a[-1]   = "Z"               #=> ["A", "Z"]
- *     a[1..-1] = nil              #=> ["A", nil]
- *     a[1..-1] = []               #=> ["A"]
- *     a[0, 0] = [ 1, 2 ]          #=> [1, 2, "A"]
- *     a[3, 0] = "B"               #=> [1, 2, "A", "B"]
+ *    self[index] = object -> object
+ *    self[start, length] = object -> object
+ *    self[range] = object -> object
+ *
+ *  Assigns elements in +self+, based on the given +object+; returns +object+.
+ *
+ *  In brief:
+ *
+ *      a_orig = [:foo, 'bar', 2]
+ *
+ *      # With argument index.
+ *      a = a_orig.dup
+ *      a[0] = 'foo' # => "foo"
+ *      a # => ["foo", "bar", 2]
+ *      a = a_orig.dup
+ *      a[7] = 'foo' # => "foo"
+ *      a # => [:foo, "bar", 2, nil, nil, nil, nil, "foo"]
+ *
+ *      # With arguments start and length.
+ *      a = a_orig.dup
+ *      a[0, 2] = 'foo' # => "foo"
+ *      a # => ["foo", 2]
+ *      a = a_orig.dup
+ *      a[6, 50] = 'foo' # => "foo"
+ *      a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *      # With argument range.
+ *      a = a_orig.dup
+ *      a[0..1] = 'foo' # => "foo"
+ *      a # => ["foo", 2]
+ *      a = a_orig.dup
+ *      a[6..50] = 'foo' # => "foo"
+ *      a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *  When Integer argument +index+ is given, assigns +object+ to an element in +self+.
+ *
+ *  If +index+ is non-negative, assigns +object+ the element at offset +index+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0] = 'foo' # => "foo"
+ *    a # => ["foo", "bar", 2]
+ *
+ *  If +index+ is greater than <tt>self.length</tt>, extends the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[7] = 'foo' # => "foo"
+ *    a # => [:foo, "bar", 2, nil, nil, nil, nil, "foo"]
+ *
+ *  If +index+ is negative, counts backwards from the end of the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[-1] = 'two' # => "two"
+ *    a # => [:foo, "bar", "two"]
+ *
+ *  When Integer arguments +start+ and +length+ are given and +object+ is not an array,
+ *  removes <tt>length - 1</tt> elements beginning at offset +start+,
+ *  and assigns +object+ at offset +start+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0, 2] = 'foo' # => "foo"
+ *    a # => ["foo", 2]
+ *
+ *  If +start+ is negative, counts backwards from the end of the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[-2, 2] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  If +start+ is non-negative and outside the array (<tt> >= self.size</tt>),
+ *  extends the array with +nil+, assigns +object+ at offset +start+,
+ *  and ignores +length+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[6, 50] = 'foo' # => "foo"
+ *    a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *  If +length+ is zero, shifts elements at and following offset +start+
+ *  and assigns +object+ at offset +start+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[1, 0] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", "bar", 2]
+ *
+ *  If +length+ is too large for the existing array, does not extend the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[1, 5] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  When Range argument +range+ is given and +object+ is not an array,
+ *  removes <tt>length - 1</tt> elements beginning at offset +start+,
+ *  and assigns +object+ at offset +start+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[0..1] = 'foo' # => "foo"
+ *    a # => ["foo", 2]
+ *
+ *  if <tt>range.begin</tt> is negative, counts backwards from the end of the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[-2..2] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  If the array length is less than <tt>range.begin</tt>,
+ *  extends the array with +nil+, assigns +object+ at offset <tt>range.begin</tt>,
+ *  and ignores +length+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[6..50] = 'foo' # => "foo"
+ *    a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *  If <tt>range.end</tt> is zero, shifts elements at and following offset +start+
+ *  and assigns +object+ at offset +start+:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[1..0] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", "bar", 2]
+ *
+ *  If <tt>range.end</tt> is negative, assigns +object+ at offset +start+,
+ *  retains <tt>range.end.abs -1</tt> elements past that, and removes those beyond:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[1..-1] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *    a = [:foo, 'bar', 2]
+ *    a[1..-2] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", 2]
+ *    a = [:foo, 'bar', 2]
+ *    a[1..-3] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", "bar", 2]
+ *    a = [:foo, 'bar', 2]
+ *
+ *  If <tt>range.end</tt> is too large for the existing array,
+ *  replaces array elements, but does not extend the array with +nil+ values:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a[1..5] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
 rb_ary_aset(int argc, VALUE *argv, VALUE ary)
 {
     long offset, beg, len;
-    VALUE rpl;
 
+    rb_check_arity(argc, 2, 3);
+    rb_ary_modify_check(ary);
     if (argc == 3) {
-	rb_ary_modify_check(ary);
-	beg = NUM2LONG(argv[0]);
-	len = NUM2LONG(argv[1]);
-	goto range;
+        beg = NUM2LONG(argv[0]);
+        len = NUM2LONG(argv[1]);
+        return ary_aset_by_rb_ary_splice(ary, beg, len, argv[2]);
     }
-    rb_check_arity(argc, 2, 2);
-    rb_ary_modify_check(ary);
     if (FIXNUM_P(argv[0])) {
-	offset = FIX2LONG(argv[0]);
-	goto fixnum;
+        offset = FIX2LONG(argv[0]);
+        return ary_aset_by_rb_ary_store(ary, offset, argv[1]);
     }
     if (rb_range_beg_len(argv[0], &beg, &len, RARRAY_LEN(ary), 1)) {
-	/* check if idx is Range */
-      range:
-	rpl = rb_ary_to_ary(argv[argc-1]);
-        rb_ary_splice(ary, beg, len, RARRAY_CONST_PTR_TRANSIENT(rpl), RARRAY_LEN(rpl));
-	RB_GC_GUARD(rpl);
-	return argv[argc-1];
+        /* check if idx is Range */
+        return ary_aset_by_rb_ary_splice(ary, beg, len, argv[1]);
     }
 
     offset = NUM2LONG(argv[0]);
-fixnum:
-    rb_ary_store(ary, offset, argv[1]);
-    return argv[1];
+    return ary_aset_by_rb_ary_store(ary, offset, argv[1]);
 }
 
 /*
  *  call-seq:
- *     ary.insert(index, obj...)  -> ary
+ *    insert(index, *objects) -> self
+ *
+ *  Inserts the given +objects+ as elements of +self+;
+ *  returns +self+.
+ *
+ *  When +index+ is non-negative, inserts +objects+
+ *  _before_ the element at offset +index+:
  *
- *  Inserts the given values before the element with the given +index+.
+ *    a = ['a', 'b', 'c']     # => ["a", "b", "c"]
+ *    a.insert(1, :x, :y, :z) # => ["a", :x, :y, :z, "b", "c"]
  *
- *  Negative indices count backwards from the end of the array, where +-1+ is
- *  the last element. If a negative index is used, the given values will be
- *  inserted after that element, so using an index of +-1+ will insert the
- *  values at the end of the array.
+ *  Extends the array if +index+ is beyond the array (<tt>index >= self.size</tt>):
  *
- *     a = %w{ a b c d }
- *     a.insert(2, 99)         #=> ["a", "b", 99, "c", "d"]
- *     a.insert(-2, 1, 2, 3)   #=> ["a", "b", 99, "c", 1, 2, 3, "d"]
+ *    a = ['a', 'b', 'c']     # => ["a", "b", "c"]
+ *    a.insert(5, :x, :y, :z) # => ["a", "b", "c", nil, nil, :x, :y, :z]
+ *
+ *  When +index+ is negative, inserts +objects+
+ *  _after_ the element at offset <tt>index + self.size</tt>:
+ *
+ *    a = ['a', 'b', 'c']      # => ["a", "b", "c"]
+ *    a.insert(-2, :x, :y, :z) # => ["a", "b", :x, :y, :z, "c"]
+ *
+ *  With no +objects+ given, does nothing:
+ *
+ *    a = ['a', 'b', 'c'] # => ["a", "b", "c"]
+ *    a.insert(1)         # => ["a", "b", "c"]
+ *    a.insert(50)        # => ["a", "b", "c"]
+ *    a.insert(-50)       # => ["a", "b", "c"]
+ *
+ *  Raises IndexError if +objects+ are given and +index+ is negative and out of range.
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -2082,15 +2661,15 @@ rb_ary_insert(int argc, VALUE *argv, VALUE ary)
     pos = NUM2LONG(argv[0]);
     if (argc == 1) return ary;
     if (pos == -1) {
-	pos = RARRAY_LEN(ary);
+        pos = RARRAY_LEN(ary);
     }
     else if (pos < 0) {
-	long minpos = -RARRAY_LEN(ary) - 1;
-	if (pos < minpos) {
-	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
-		     pos, minpos);
-	}
-	pos++;
+        long minpos = -RARRAY_LEN(ary) - 1;
+        if (pos < minpos) {
+            rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+                     pos, minpos);
+        }
+        pos++;
     }
     rb_ary_splice(ary, pos, 0, argv + 1, argc - 1);
     return ary;
@@ -2105,22 +2684,72 @@ ary_enum_length(VALUE ary, VALUE args, VALUE eobj)
     return rb_ary_length(ary);
 }
 
+// These array primitives enable tight compatibility with the C implementation
+// in terms of what method calls happen. They can use unchecked utilities such as
+// FIX2LONG since unlike userland Ruby code, these methods cannot be traced with
+// TracePoint (or ruby/debug.h APIs) and have their local variables changed from
+// underneath them.
+
+// Return true if the index is at or past the end of the array.
+VALUE
+rb_jit_ary_at_end(rb_execution_context_t *ec, VALUE self, VALUE index)
+{
+    return FIX2LONG(index) >= RARRAY_LEN(self) ? Qtrue : Qfalse;
+}
+
+// Return the element at the given fixnum index.
+VALUE
+rb_jit_ary_at(rb_execution_context_t *ec, VALUE self, VALUE index)
+{
+    return RARRAY_AREF(self, FIX2LONG(index));
+}
+
+// Increment a fixnum by 1.
+VALUE
+rb_jit_fixnum_inc(rb_execution_context_t *ec, VALUE self, VALUE num)
+{
+    return LONG2FIX(FIX2LONG(num) + 1);
+}
+
+// Push a value onto an array and return the value.
+VALUE
+rb_jit_ary_push(rb_execution_context_t *ec, VALUE self, VALUE ary, VALUE val)
+{
+    rb_ary_push(ary, val);
+    return val;
+}
+
 /*
  *  call-seq:
- *     ary.each {|item| block}    -> ary
- *     ary.each                   -> Enumerator
+ *    each {|element| ... } -> self
+ *    each -> new_enumerator
  *
- *  Calls the given block once for each element in +self+, passing that element
- *  as a parameter.  Returns the array itself.
+ *  With a block given, iterates over the elements of +self+,
+ *  passing each element to the block;
+ *  returns +self+:
  *
- *  If no block is given, an Enumerator is returned.
+ *    a = [:foo, 'bar', 2]
+ *    a.each {|element|  puts "#{element.class} #{element}" }
  *
- *     a = [ "a", "b", "c" ]
- *     a.each {|x| print x, " -- " }
+ *  Output:
  *
- *  produces:
+ *    Symbol foo
+ *    String bar
+ *    Integer 2
  *
- *     a -- b -- c --
+ *  Allows the array to be modified during iteration:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.each {|element| puts element; a.clear if element.to_s.start_with?('b') }
+ *
+ *  Output:
+ *
+ *    foo
+ *    bar
+ *
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 VALUE
@@ -2130,27 +2759,43 @@ rb_ary_each(VALUE ary)
     ary_verify(ary);
     RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	rb_yield(RARRAY_AREF(ary, i));
+        rb_yield(RARRAY_AREF(ary, i));
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.each_index {|index| block}    -> ary
- *     ary.each_index                    -> Enumerator
+ *    each_index {|index| ... } -> self
+ *    each_index -> new_enumerator
+ *
+ *  With a block given, iterates over the elements of +self+,
+ *  passing each <i>array index</i> to the block;
+ *  returns +self+:
  *
- *  Same as Array#each, but passes the +index+ of the element instead of the
- *  element itself.
+ *    a = [:foo, 'bar', 2]
+ *    a.each_index {|index|  puts "#{index} #{a[index]}" }
  *
- *  An Enumerator is returned if no block is given.
+ *  Output:
  *
- *     a = [ "a", "b", "c" ]
- *     a.each_index {|x| print x, " -- " }
+ *    0 foo
+ *    1 bar
+ *    2 2
  *
- *  produces:
+ *  Allows the array to be modified during iteration:
  *
- *     0 -- 1 -- 2 --
+ *    a = [:foo, 'bar', 2]
+ *    a.each_index {|index| puts index; a.clear if index > 0 }
+ *    a # => []
+ *
+ *  Output:
+ *
+ *    0
+ *    1
+ *
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -2160,24 +2805,33 @@ rb_ary_each_index(VALUE ary)
     RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
 
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	rb_yield(LONG2NUM(i));
+        rb_yield(LONG2NUM(i));
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.reverse_each {|item| block}    -> ary
- *     ary.reverse_each                   -> Enumerator
+ *    reverse_each {|element| ... } -> self
+ *    reverse_each -> Enumerator
+ *
+ *  When a block given, iterates backwards over the elements of +self+,
+ *  passing, in reverse order, each element to the block;
+ *  returns +self+:
+ *
+ *    a = []
+ *    [0, 1, 2].reverse_each {|element| a.push(element) }
+ *    a # => [2, 1, 0]
  *
- *  Same as Array#each, but traverses +self+ in reverse order.
+ *  Allows the array to be modified during iteration:
  *
- *     a = [ "a", "b", "c" ]
- *     a.reverse_each {|x| print x, " " }
+ *    a = ['a', 'b', 'c']
+ *    a.reverse_each {|element| a.clear if element.start_with?('b') }
+ *    a # => []
  *
- *  produces:
+ *  When no block given, returns a new Enumerator.
  *
- *     c b a
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -2188,24 +2842,27 @@ rb_ary_reverse_each(VALUE ary)
     RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
     len = RARRAY_LEN(ary);
     while (len--) {
-	long nlen;
-	rb_yield(RARRAY_AREF(ary, len));
-	nlen = RARRAY_LEN(ary);
-	if (nlen < len) {
-	    len = nlen;
-	}
+        long nlen;
+        rb_yield(RARRAY_AREF(ary, len));
+        nlen = RARRAY_LEN(ary);
+        if (nlen < len) {
+            len = nlen;
+        }
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.length -> int
+ *    length -> integer
+ *    size -> integer
+ *
+ *  Returns the count of elements in +self+:
  *
- *  Returns the number of elements in +self+. May be zero.
+ *    [0, 1, 2].length # => 3
+ *    [].length        # => 0
  *
- *     [ 1, 2, 3, 4, 5 ].length   #=> 5
- *     [].length                  #=> 0
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2217,19 +2874,18 @@ rb_ary_length(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.empty?   -> true or false
+ *    empty?  -> true or false
  *
- *  Returns +true+ if +self+ contains no elements.
+ *  Returns +true+ if the count of elements in +self+ is zero,
+ *  +false+ otherwise.
  *
- *     [].empty?   #=> true
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
 rb_ary_empty_p(VALUE ary)
 {
-    if (RARRAY_LEN(ary) == 0)
-	return Qtrue;
-    return Qfalse;
+    return RBOOL(RARRAY_LEN(ary) == 0);
 }
 
 VALUE
@@ -2237,7 +2893,7 @@ rb_ary_dup(VALUE ary)
 {
     long len = RARRAY_LEN(ary);
     VALUE dup = rb_ary_new2(len);
-    ary_memcpy(dup, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary));
+    ary_memcpy(dup, 0, len, RARRAY_CONST_PTR(ary));
     ARY_SET_LEN(dup, len);
 
     ary_verify(ary);
@@ -2265,15 +2921,15 @@ recursive_join(VALUE obj, VALUE argp, int recur)
     int *first = (int *)arg[3];
 
     if (recur) {
-	rb_raise(rb_eArgError, "recursive array join");
+        rb_raise(rb_eArgError, "recursive array join");
     }
     else {
-	ary_join_1(obj, ary, sep, 0, result, first);
+        ary_join_1(obj, ary, sep, 0, result, first);
     }
     return Qnil;
 }
 
-static void
+static long
 ary_join_0(VALUE ary, VALUE sep, long max, VALUE result)
 {
     long i;
@@ -2281,11 +2937,40 @@ ary_join_0(VALUE ary, VALUE sep, long max, VALUE result)
 
     if (max > 0) rb_enc_copy(result, RARRAY_AREF(ary, 0));
     for (i=0; i<max; i++) {
-	val = RARRAY_AREF(ary, i);
-	if (i > 0 && !NIL_P(sep))
-	    rb_str_buf_append(result, sep);
-	rb_str_buf_append(result, val);
-	if (OBJ_TAINTED(val)) OBJ_TAINT(result);
+        val = RARRAY_AREF(ary, i);
+        if (!RB_TYPE_P(val, T_STRING)) break;
+        if (i > 0 && !NIL_P(sep))
+            rb_str_buf_append(result, sep);
+        rb_str_buf_append(result, val);
+    }
+    return i;
+}
+
+static void
+ary_join_1_str(VALUE dst, VALUE src, int *first)
+{
+    rb_str_buf_append(dst, src);
+    if (*first) {
+        rb_enc_copy(dst, src);
+        *first = FALSE;
+    }
+}
+
+static void
+ary_join_1_ary(VALUE obj, VALUE ary, VALUE sep, VALUE result, VALUE val, int *first)
+{
+    if (val == ary) {
+        rb_raise(rb_eArgError, "recursive array join");
+    }
+    else {
+        VALUE args[4];
+
+        *first = FALSE;
+        args[0] = val;
+        args[1] = sep;
+        args[2] = result;
+        args[3] = (VALUE)first;
+        rb_exec_recursive(recursive_join, obj, (VALUE)args);
     }
 }
 
@@ -2295,50 +2980,25 @@ ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first)
     VALUE val, tmp;
 
     for (; i<RARRAY_LEN(ary); i++) {
-	if (i > 0 && !NIL_P(sep))
-	    rb_str_buf_append(result, sep);
-
-	val = RARRAY_AREF(ary, i);
-	if (RB_TYPE_P(val, T_STRING)) {
-	  str_join:
-	    rb_str_buf_append(result, val);
-	    if (*first) {
-		rb_enc_copy(result, val);
-		*first = FALSE;
-	    }
-	}
-	else if (RB_TYPE_P(val, T_ARRAY)) {
-	    obj = val;
-	  ary_join:
-	    if (val == ary) {
-		rb_raise(rb_eArgError, "recursive array join");
-	    }
-	    else {
-		VALUE args[4];
-
-		*first = FALSE;
-		args[0] = val;
-		args[1] = sep;
-		args[2] = result;
-		args[3] = (VALUE)first;
-		rb_exec_recursive(recursive_join, obj, (VALUE)args);
-	    }
-	}
-	else {
-	    tmp = rb_check_string_type(val);
-	    if (!NIL_P(tmp)) {
-		val = tmp;
-		goto str_join;
-	    }
-	    tmp = rb_check_array_type(val);
-	    if (!NIL_P(tmp)) {
-		obj = val;
-		val = tmp;
-		goto ary_join;
-	    }
-	    val = rb_obj_as_string(val);
-	    goto str_join;
-	}
+        if (i > 0 && !NIL_P(sep))
+            rb_str_buf_append(result, sep);
+
+        val = RARRAY_AREF(ary, i);
+        if (RB_TYPE_P(val, T_STRING)) {
+            ary_join_1_str(result, val, first);
+        }
+        else if (RB_TYPE_P(val, T_ARRAY)) {
+            ary_join_1_ary(val, ary, sep, result, val, first);
+        }
+        else if (!NIL_P(tmp = rb_check_string_type(val))) {
+            ary_join_1_str(result, tmp, first);
+        }
+        else if (!NIL_P(tmp = rb_check_array_type(val))) {
+            ary_join_1_ary(val, ary, sep, result, tmp, first);
+        }
+        else {
+            ary_join_1_str(result, rb_obj_as_string(val), first);
+        }
     }
 }
 
@@ -2346,38 +3006,41 @@ VALUE
 rb_ary_join(VALUE ary, VALUE sep)
 {
     long len = 1, i;
-    int taint = FALSE;
     VALUE val, tmp, result;
 
     if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new(0, 0);
-    if (OBJ_TAINTED(ary)) taint = TRUE;
 
     if (!NIL_P(sep)) {
-	StringValue(sep);
-	len += RSTRING_LEN(sep) * (RARRAY_LEN(ary) - 1);
-    }
-    for (i=0; i<RARRAY_LEN(ary); i++) {
-	val = RARRAY_AREF(ary, i);
-	tmp = rb_check_string_type(val);
-
-	if (NIL_P(tmp) || tmp != val) {
-	    int first;
-	    result = rb_str_buf_new(len + (RARRAY_LEN(ary)-i)*10);
-	    rb_enc_associate(result, rb_usascii_encoding());
-	    if (taint) OBJ_TAINT(result);
-	    ary_join_0(ary, sep, i, result);
-	    first = i == 0;
-	    ary_join_1(ary, ary, sep, i, result, &first);
-	    return result;
-	}
-
-	len += RSTRING_LEN(tmp);
+        StringValue(sep);
+        len += RSTRING_LEN(sep) * (RARRAY_LEN(ary) - 1);
+    }
+    long len_memo = RARRAY_LEN(ary);
+    for (i=0; i < len_memo; i++) {
+        val = RARRAY_AREF(ary, i);
+        if (RB_UNLIKELY(!RB_TYPE_P(val, T_STRING))) {
+            tmp = rb_check_string_type(val);
+            if (NIL_P(tmp) || tmp != val) {
+                int first;
+                long n = RARRAY_LEN(ary);
+                if (i > n) i = n;
+                result = rb_str_buf_new(len + (n-i)*10);
+                rb_enc_associate(result, rb_usascii_encoding());
+                i = ary_join_0(ary, sep, i, result);
+                first = i == 0;
+                ary_join_1(ary, ary, sep, i, result, &first);
+                return result;
+            }
+            len += RSTRING_LEN(tmp);
+            len_memo = RARRAY_LEN(ary);
+        }
+        else {
+            len += RSTRING_LEN(val);
+        }
     }
 
     result = rb_str_new(0, len);
     rb_str_set_len(result, 0);
 
-    if (taint) OBJ_TAINT(result);
     ary_join_0(ary, sep, RARRAY_LEN(ary), result);
 
     return result;
@@ -2385,22 +3048,33 @@ rb_ary_join(VALUE ary, VALUE sep)
 
 /*
  *  call-seq:
- *     ary.join(separator=$,)    -> str
+ *    join(separator = $,) -> new_string
+ *
+ *  Returns the new string formed by joining the converted elements of +self+;
+ *  for each element +element+:
+ *
+ *  - Converts recursively using <tt>element.join(separator)</tt>
+ *    if +element+ is a <tt>kind_of?(Array)</tt>.
+ *  - Otherwise, converts using <tt>element.to_s</tt>.
  *
- *  Returns a string created by converting each element of the array to
- *  a string, separated by the given +separator+.
- *  If the +separator+ is +nil+, it uses current <code>$,</code>.
- *  If both the +separator+ and <code>$,</code> are +nil+,
- *  it uses an empty string.
+ *  With no argument given, joins using the output field separator, <tt>$,</tt>:
  *
- *     [ "a", "b", "c" ].join        #=> "abc"
- *     [ "a", "b", "c" ].join("-")   #=> "a-b-c"
+ *    a = [:foo, 'bar', 2]
+ *    $, # => nil
+ *    a.join # => "foobar2"
  *
- *  For nested arrays, join is applied recursively:
+ *  With string argument +separator+ given, joins using that separator:
  *
- *     [ "a", [1, 2, [:x, :y]], "b" ].join("-")   #=> "a-1-2-x-y-b"
+ *    a = [:foo, 'bar', 2]
+ *    a.join("\n") # => "foo\nbar\n2"
+ *
+ *  Joins recursively for nested arrays:
+ *
+ *   a = [:foo, [:bar, [:baz, :bat]]]
+ *   a.join # => "foobarbazbat"
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
-
 static VALUE
 rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
 {
@@ -2409,7 +3083,7 @@ rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
     if (rb_check_arity(argc, 0, 1) == 0 || NIL_P(sep = argv[0])) {
         sep = rb_output_fs;
         if (!NIL_P(sep)) {
-            rb_warn("$, is set to non-nil value");
+            rb_category_warn(RB_WARN_CATEGORY_DEPRECATED, "$, is set to non-nil value");
         }
     }
 
@@ -2419,33 +3093,33 @@ rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
 static VALUE
 inspect_ary(VALUE ary, VALUE dummy, int recur)
 {
-    int tainted = OBJ_TAINTED(ary);
     long i;
     VALUE s, str;
 
     if (recur) return rb_usascii_str_new_cstr("[...]");
     str = rb_str_buf_new2("[");
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	s = rb_inspect(RARRAY_AREF(ary, i));
-	if (OBJ_TAINTED(s)) tainted = TRUE;
-	if (i > 0) rb_str_buf_cat2(str, ", ");
-	else rb_enc_copy(str, s);
-	rb_str_buf_append(str, s);
+        s = rb_inspect(RARRAY_AREF(ary, i));
+        if (i > 0) rb_str_buf_cat2(str, ", ");
+        else rb_enc_copy(str, s);
+        rb_str_buf_append(str, s);
     }
     rb_str_buf_cat2(str, "]");
-    if (tainted) OBJ_TAINT(str);
     return str;
 }
 
 /*
  *  call-seq:
- *     ary.inspect  -> string
- *     ary.to_s     -> string
+ *    inspect -> new_string
+ *    to_s -> new_string
+ *
+ *  Returns the new string formed by calling method <tt>#inspect</tt>
+ *  on each array element:
  *
- *  Creates a string representation of +self+, by calling #inspect
- *  on each element.
+ *    a = [:foo, 'bar', 2]
+ *    a.inspect # => "[:foo, \"bar\", 2]"
  *
- *     [ "a", "b", "c" ].to_s     #=> "[\"a\", \"b\", \"c\"]"
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -2463,40 +3137,55 @@ rb_ary_to_s(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.to_a     -> ary
+ *    to_a -> self or new_array
  *
- *  Returns +self+.
+ *  When +self+ is an instance of \Array, returns +self+.
  *
- *  If called on a subclass of Array, converts the receiver to an Array object.
+ *  Otherwise, returns a new array containing the elements of +self+:
+ *
+ *    class MyArray < Array; end
+ *    my_a = MyArray.new(['foo', 'bar', 'two'])
+ *    a = my_a.to_a
+ *    a # => ["foo", "bar", "two"]
+ *    a.class # => Array # Not MyArray.
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
 rb_ary_to_a(VALUE ary)
 {
     if (rb_obj_class(ary) != rb_cArray) {
-	VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
-	rb_ary_replace(dup, ary);
-	return dup;
+        VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
+        rb_ary_replace(dup, ary);
+        return dup;
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.to_h                  -> hash
- *     ary.to_h {|item| block }  -> hash
+ *    to_h -> new_hash
+ *    to_h {|element| ... } -> new_hash
+ *
+ *  Returns a new hash formed from +self+.
  *
- *  Returns the result of interpreting <i>ary</i> as an array of
- *  <tt>[key, value]</tt> pairs.
+ *  With no block given, each element of +self+ must be a 2-element sub-array;
+ *  forms each sub-array into a key-value pair in the new hash:
  *
- *     [[:foo, :bar], [1, 2]].to_h
- *       # => {:foo => :bar, 1 => 2}
+ *    a = [['foo', 'zero'], ['bar', 'one'], ['baz', 'two']]
+ *    a.to_h # => {"foo" => "zero", "bar" => "one", "baz" => "two"}
+ *    [].to_h # => {}
  *
- *  If a block is given, the results of the block on each element of
- *  the array will be used as pairs.
+ *  With a block given, the block must return a 2-element array;
+ *  calls the block with each element of +self+;
+ *  forms each returned array into a key-value pair in the returned hash:
  *
- *     ["foo", "bar"].to_h {|s| [s.ord, s]}
- *       # => {102=>"foo", 98=>"bar"}
+ *    a = ['foo', :bar, 1, [2, 3], {baz: 4}]
+ *    a.to_h {|element| [element, element.class] }
+ *    # => {"foo" => String, bar: Symbol, 1 => Integer, [2, 3] => Array, {baz: 4} => Hash}
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -2507,25 +3196,25 @@ rb_ary_to_h(VALUE ary)
     int block_given = rb_block_given_p();
 
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	const VALUE e = rb_ary_elt(ary, i);
-	const VALUE elt = block_given ? rb_yield_force_blockarg(e) : e;
-	const VALUE key_value_pair = rb_check_array_type(elt);
-	if (NIL_P(key_value_pair)) {
-	    rb_raise(rb_eTypeError, "wrong element type %"PRIsVALUE" at %ld (expected array)",
-		     rb_obj_class(elt), i);
-	}
-	if (RARRAY_LEN(key_value_pair) != 2) {
-	    rb_raise(rb_eArgError, "wrong array length at %ld (expected 2, was %ld)",
-		i, RARRAY_LEN(key_value_pair));
-	}
-	rb_hash_aset(hash, RARRAY_AREF(key_value_pair, 0), RARRAY_AREF(key_value_pair, 1));
+        const VALUE e = rb_ary_elt(ary, i);
+        const VALUE elt = block_given ? rb_yield_force_blockarg(e) : e;
+        const VALUE key_value_pair = rb_check_array_type(elt);
+        if (NIL_P(key_value_pair)) {
+            rb_raise(rb_eTypeError, "wrong element type %"PRIsVALUE" at %ld (expected array)",
+                     rb_obj_class(elt), i);
+        }
+        if (RARRAY_LEN(key_value_pair) != 2) {
+            rb_raise(rb_eArgError, "wrong array length at %ld (expected 2, was %ld)",
+                i, RARRAY_LEN(key_value_pair));
+        }
+        rb_hash_aset(hash, RARRAY_AREF(key_value_pair, 0), RARRAY_AREF(key_value_pair, 1));
     }
     return hash;
 }
 
 /*
  *  call-seq:
- *     ary.to_ary -> ary
+ *    to_ary -> self
  *
  *  Returns +self+.
  */
@@ -2540,9 +3229,9 @@ static void
 ary_reverse(VALUE *p1, VALUE *p2)
 {
     while (p1 < p2) {
-	VALUE tmp = *p1;
-	*p1++ = *p2;
-	*p2-- = tmp;
+        VALUE tmp = *p1;
+        *p1++ = *p2;
+        *p2-- = tmp;
     }
 }
 
@@ -2554,23 +3243,26 @@ rb_ary_reverse(VALUE ary)
 
     rb_ary_modify(ary);
     if (len > 1) {
-        RARRAY_PTR_USE_TRANSIENT(ary, p1, {
+        RARRAY_PTR_USE(ary, p1, {
             p2 = p1 + len - 1;	/* points last item */
             ary_reverse(p1, p2);
-	}); /* WB: no new reference */
+        }); /* WB: no new reference */
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.reverse!   -> ary
+ *    reverse! -> self
  *
- *  Reverses +self+ in place.
+ *  Reverses the order of the elements of +self+;
+ *  returns +self+:
  *
- *     a = [ "a", "b", "c" ]
- *     a.reverse!       #=> ["c", "b", "a"]
- *     a                #=> ["c", "b", "a"]
+ *    a = [0, 1, 2]
+ *    a.reverse! # => [2, 1, 0]
+ *    a          # => [2, 1, 0]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -2581,12 +3273,13 @@ rb_ary_reverse_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.reverse    -> new_ary
+ *    reverse -> new_array
+ *
+ *  Returns a new array containing the elements of +self+ in reverse order:
  *
- *  Returns a new array containing +self+'s elements in reverse order.
+ *    [0, 1, 2].reverse # => [2, 1, 0]
  *
- *     [ "a", "b", "c" ].reverse   #=> ["c", "b", "a"]
- *     [ 1 ].reverse               #=> [1]
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -2596,9 +3289,9 @@ rb_ary_reverse_m(VALUE ary)
     VALUE dup = rb_ary_new2(len);
 
     if (len > 0) {
-        const VALUE *p1 = RARRAY_CONST_PTR_TRANSIENT(ary);
-        VALUE *p2 = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(dup) + len - 1;
-	do *p2-- = *p1++; while (--len > 0);
+        const VALUE *p1 = RARRAY_CONST_PTR(ary);
+        VALUE *p2 = (VALUE *)RARRAY_CONST_PTR(dup) + len - 1;
+        do *p2-- = *p1++; while (--len > 0);
     }
     ARY_SET_LEN(dup, RARRAY_LEN(ary));
     return dup;
@@ -2613,10 +3306,22 @@ rotate_count(long cnt, long len)
 static void
 ary_rotate_ptr(VALUE *ptr, long len, long cnt)
 {
-    --len;
-    if (cnt < len) ary_reverse(ptr + cnt, ptr + len);
-    if (--cnt > 0) ary_reverse(ptr, ptr + cnt);
-    if (len > 0) ary_reverse(ptr, ptr + len);
+    if (cnt == 1) {
+        VALUE tmp = *ptr;
+        memmove(ptr, ptr + 1, sizeof(VALUE)*(len - 1));
+        *(ptr + len - 1) = tmp;
+    }
+    else if (cnt == len - 1) {
+        VALUE tmp = *(ptr + len - 1);
+        memmove(ptr + 1, ptr, sizeof(VALUE)*(len - 1));
+        *ptr = tmp;
+    }
+    else {
+        --len;
+        if (cnt < len) ary_reverse(ptr + cnt, ptr + len);
+        if (--cnt > 0) ary_reverse(ptr, ptr + cnt);
+        if (len > 0) ary_reverse(ptr, ptr + len);
+    }
 }
 
 VALUE
@@ -2626,8 +3331,8 @@ rb_ary_rotate(VALUE ary, long cnt)
 
     if (cnt != 0) {
         long len = RARRAY_LEN(ary);
-        if (len > 0 && (cnt = rotate_count(cnt, len)) > 0) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, ary_rotate_ptr(ptr, len, cnt));
+        if (len > 1 && (cnt = rotate_count(cnt, len)) > 0) {
+            RARRAY_PTR_USE(ary, ptr, ary_rotate_ptr(ptr, len, cnt));
             return ary;
         }
     }
@@ -2636,19 +3341,34 @@ rb_ary_rotate(VALUE ary, long cnt)
 
 /*
  *  call-seq:
- *     ary.rotate!(count=1)   -> ary
+ *    rotate!(count = 1) -> self
  *
- *  Rotates +self+ in place so that the element at +count+ comes first, and
- *  returns +self+.
+ *  Rotates +self+ in place by moving elements from one end to the other; returns +self+.
+ *
+ *  With non-negative numeric +count+,
+ *  rotates +count+ elements from the beginning to the end:
+ *
+ *    [0, 1, 2, 3].rotate!(2)   # => [2, 3, 0, 1]
+      [0, 1, 2, 3].rotate!(2.1) # => [2, 3, 0, 1]
+ *
+ *  If +count+ is large, uses <tt>count % array.size</tt> as the count:
+ *
+ *    [0, 1, 2, 3].rotate!(21) # => [1, 2, 3, 0]
  *
- *  If +count+ is negative then it rotates in the opposite direction, starting
- *  from the end of the array where +-1+ is the last element.
+ *  If +count+ is zero, rotates no elements:
  *
- *     a = [ "a", "b", "c", "d" ]
- *     a.rotate!        #=> ["b", "c", "d", "a"]
- *     a                #=> ["b", "c", "d", "a"]
- *     a.rotate!(2)     #=> ["d", "a", "b", "c"]
- *     a.rotate!(-3)    #=> ["a", "b", "c", "d"]
+ *    [0, 1, 2, 3].rotate!(0) # => [0, 1, 2, 3]
+ *
+ *  With a negative numeric +count+, rotates in the opposite direction,
+ *  from end to beginning:
+ *
+ *    [0, 1, 2, 3].rotate!(-1) # => [3, 0, 1, 2]
+ *
+ *  If +count+ is small (far from zero), uses <tt>count % array.size</tt> as the count:
+ *
+ *    [0, 1, 2, 3].rotate!(-21) # => [3, 0, 1, 2]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -2661,19 +3381,35 @@ rb_ary_rotate_bang(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.rotate(count=1)    -> new_ary
+ *    rotate(count = 1) -> new_array
+ *
+ *  Returns a new array formed from +self+ with elements
+ *  rotated from one end to the other.
+ *
+ *  With non-negative numeric +count+,
+ *  rotates elements from the beginning to the end:
+ *
+ *    [0, 1, 2, 3].rotate(2)   # => [2, 3, 0, 1]
+ *    [0, 1, 2, 3].rotate(2.1) # => [2, 3, 0, 1]
+ *
+ *  If +count+ is large, uses <tt>count % array.size</tt> as the count:
+ *
+ *    [0, 1, 2, 3].rotate(22) # => [2, 3, 0, 1]
+ *
+ *  With a +count+ of zero, rotates no elements:
+ *
+ *    [0, 1, 2, 3].rotate(0) # => [0, 1, 2, 3]
  *
- *  Returns a new array by rotating +self+ so that the element at +count+ is
- *  the first element of the new array.
+ *  With negative numeric +count+, rotates in the opposite direction,
+ *  from the end to the beginning:
  *
- *  If +count+ is negative then it rotates in the opposite direction, starting
- *  from the end of +self+ where +-1+ is the last element.
+ *    [0, 1, 2, 3].rotate(-1) # => [3, 0, 1, 2]
  *
- *     a = [ "a", "b", "c", "d" ]
- *     a.rotate         #=> ["b", "c", "d", "a"]
- *     a                #=> ["a", "b", "c", "d"]
- *     a.rotate(2)      #=> ["c", "d", "a", "b"]
- *     a.rotate(-3)     #=> ["b", "c", "d", "a"]
+ *  If +count+ is small (far from zero), uses <tt>count % array.size</tt> as the count:
+ *
+ *    [0, 1, 2, 3].rotate(-21) # => [3, 0, 1, 2]
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -2687,11 +3423,11 @@ rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
     len = RARRAY_LEN(ary);
     rotated = rb_ary_new2(len);
     if (len > 0) {
-	cnt = rotate_count(cnt, len);
-        ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
-	len -= cnt;
-	ary_memcpy(rotated, 0, len, ptr + cnt);
-	ary_memcpy(rotated, len, cnt, ptr);
+        cnt = rotate_count(cnt, len);
+        ptr = RARRAY_CONST_PTR(ary);
+        len -= cnt;
+        ary_memcpy(rotated, 0, len, ptr + cnt);
+        ary_memcpy(rotated, len, cnt, ptr);
     }
     ARY_SET_LEN(rotated, RARRAY_LEN(ary));
     return rotated;
@@ -2699,18 +3435,27 @@ rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
 
 struct ary_sort_data {
     VALUE ary;
-    struct cmp_opt_data cmp_opt;
+    VALUE receiver;
 };
 
 static VALUE
 sort_reentered(VALUE ary)
 {
     if (RBASIC(ary)->klass) {
-	rb_raise(rb_eRuntimeError, "sort reentered");
+        rb_raise(rb_eRuntimeError, "sort reentered");
     }
     return Qnil;
 }
 
+static void
+sort_returned(struct ary_sort_data *data)
+{
+    if (rb_obj_frozen_p(data->receiver)) {
+        rb_raise(rb_eFrozenError, "array frozen during sort");
+    }
+    sort_reentered(data->ary);
+}
+
 static int
 sort_1(const void *ap, const void *bp, void *dummy)
 {
@@ -2724,7 +3469,7 @@ sort_1(const void *ap, const void *bp, void *dummy)
     args[1] = b;
     retval = rb_yield_values2(2, args);
     n = rb_cmpint(retval, a, b);
-    sort_reentered(data->ary);
+    sort_returned(data);
     return n;
 }
 
@@ -2736,73 +3481,61 @@ sort_2(const void *ap, const void *bp, void *dummy)
     VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
     int n;
 
-    if (FIXNUM_P(a) && FIXNUM_P(b) && CMP_OPTIMIZABLE(data->cmp_opt, Fixnum)) {
-	if ((long)a > (long)b) return 1;
-	if ((long)a < (long)b) return -1;
-	return 0;
+    if (FIXNUM_P(a) && FIXNUM_P(b) && CMP_OPTIMIZABLE(INTEGER)) {
+        if ((long)a > (long)b) return 1;
+        if ((long)a < (long)b) return -1;
+        return 0;
     }
-    if (STRING_P(a) && STRING_P(b) && CMP_OPTIMIZABLE(data->cmp_opt, String)) {
-	return rb_str_cmp(a, b);
+    if (STRING_P(a) && STRING_P(b) && CMP_OPTIMIZABLE(STRING)) {
+        return rb_str_cmp(a, b);
     }
-    if (RB_FLOAT_TYPE_P(a) && CMP_OPTIMIZABLE(data->cmp_opt, Float)) {
-	return rb_float_cmp(a, b);
+    if (RB_FLOAT_TYPE_P(a) && CMP_OPTIMIZABLE(FLOAT)) {
+        return rb_float_cmp(a, b);
     }
 
     retval = rb_funcallv(a, id_cmp, 1, &b);
     n = rb_cmpint(retval, a, b);
-    sort_reentered(data->ary);
+    sort_returned(data);
 
     return n;
 }
 
 /*
  *  call-seq:
- *     ary.sort!                   -> ary
- *     ary.sort! {|a, b| block}    -> ary
- *
- *  Sorts +self+ in place.
- *
- *  Comparisons for the sort will be done using the <code><=></code> operator
- *  or using an optional code block.
+ *    sort! -> self
+ *    sort! {|a, b| ... } -> self
  *
- *  The block must implement a comparison between +a+ and +b+ and return
- *  an integer less than 0 when +b+ follows +a+, +0+ when +a+ and +b+
- *  are equivalent, or an integer greater than 0 when +a+ follows +b+.
+ *  Like Array#sort, but returns +self+ with its elements sorted in place.
  *
- *  The result is not guaranteed to be stable.  When the comparison of two
- *  elements returns +0+, the order of the elements is unpredictable.
- *
- *     ary = [ "d", "a", "e", "c", "b" ]
- *     ary.sort!                     #=> ["a", "b", "c", "d", "e"]
- *     ary.sort! {|a, b| b <=> a}    #=> ["e", "d", "c", "b", "a"]
- *
- *  See also Enumerable#sort_by.
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
 rb_ary_sort_bang(VALUE ary)
 {
     rb_ary_modify(ary);
-    assert(!ARY_SHARED_P(ary));
+    RUBY_ASSERT(!ARY_SHARED_P(ary));
     if (RARRAY_LEN(ary) > 1) {
-	VALUE tmp = ary_make_substitution(ary); /* only ary refers tmp */
-	struct ary_sort_data data;
-	long len = RARRAY_LEN(ary);
-	RBASIC_CLEAR_CLASS(tmp);
-	data.ary = tmp;
-	data.cmp_opt.opt_methods = 0;
-	data.cmp_opt.opt_inited = 0;
-	RARRAY_PTR_USE(tmp, ptr, {
+        VALUE tmp = ary_make_substitution(ary); /* only ary refers tmp */
+        struct ary_sort_data data;
+        long len = RARRAY_LEN(ary);
+        RBASIC_CLEAR_CLASS(tmp);
+        data.ary = tmp;
+        data.receiver = ary;
+        RARRAY_PTR_USE(tmp, ptr, {
             ruby_qsort(ptr, len, sizeof(VALUE),
                        rb_block_given_p()?sort_1:sort_2, &data);
-	}); /* WB: no new reference */
-	rb_ary_modify(ary);
+        }); /* WB: no new reference */
+        rb_ary_modify(ary);
         if (ARY_EMBED_P(tmp)) {
             if (ARY_SHARED_P(ary)) { /* ary might be destructively operated in the given block */
                 rb_ary_unshare(ary);
-		FL_SET_EMBED(ary);
+                FL_SET_EMBED(ary);
+            }
+            if (ARY_EMBED_LEN(tmp) > ARY_CAPA(ary)) {
+                ary_resize_capa(ary, ARY_EMBED_LEN(tmp));
             }
-	    ary_memcpy(ary, 0, ARY_EMBED_LEN(tmp), ARY_EMBED_PTR(tmp));
+            ary_memcpy(ary, 0, ARY_EMBED_LEN(tmp), ARY_EMBED_PTR(tmp));
             ARY_SET_LEN(ary, ARY_EMBED_LEN(tmp));
         }
         else {
@@ -2811,7 +3544,7 @@ rb_ary_sort_bang(VALUE ary)
                 ARY_SET_CAPA(ary, RARRAY_LEN(tmp));
             }
             else {
-                assert(!ARY_SHARED_P(tmp));
+                RUBY_ASSERT(!ARY_SHARED_P(tmp));
                 if (ARY_EMBED_P(ary)) {
                     FL_UNSET_EMBED(ary);
                 }
@@ -2827,10 +3560,9 @@ rb_ary_sort_bang(VALUE ary)
                 ARY_SET_CAPA(ary, ARY_HEAP_LEN(tmp));
             }
             /* tmp was lost ownership for the ptr */
-            FL_UNSET(tmp, FL_FREEZE);
             FL_SET_EMBED(tmp);
             ARY_SET_EMBED_LEN(tmp, 0);
-            FL_SET(tmp, FL_FREEZE);
+            OBJ_FREEZE(tmp);
         }
         /* tmp will be GC'ed. */
         RBASIC_SET_CLASS_RAW(tmp, rb_cArray); /* rb_cArray must be marked */
@@ -2841,31 +3573,36 @@ rb_ary_sort_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.sort                   -> new_ary
- *     ary.sort {|a, b| block}    -> new_ary
+ *    sort -> new_array
+ *    sort {|a, b| ... } -> new_array
+ *
+ *  Returns a new array containing the elements of +self+, sorted.
  *
- *  Returns a new array created by sorting +self+.
+ *  With no block given, compares elements using operator <tt>#<=></tt>
+ *  (see Object#<=>):
  *
- *  Comparisons for the sort will be done using the <code><=></code> operator
- *  or using an optional code block.
+ *    [0, 2, 3, 1].sort # => [0, 1, 2, 3]
  *
- *  The block must implement a comparison between +a+ and +b+ and return
- *  an integer less than 0 when +b+ follows +a+, +0+ when +a+ and +b+
- *  are equivalent, or an integer greater than 0 when +a+ follows +b+.
+ *  With a block given, calls the block with each combination of pairs of elements from +self+;
+ *  for each pair +a+ and +b+, the block should return a numeric:
  *
- *  The result is not guaranteed to be stable.  When the comparison of two
- *  elements returns +0+, the order of the elements is unpredictable.
+ *  - Negative when +b+ is to follow +a+.
+ *  - Zero when +a+ and +b+ are equivalent.
+ *  - Positive when +a+ is to follow +b+.
  *
- *     ary = [ "d", "a", "e", "c", "b" ]
- *     ary.sort                     #=> ["a", "b", "c", "d", "e"]
- *     ary.sort {|a, b| b <=> a}    #=> ["e", "d", "c", "b", "a"]
+ *  Example:
  *
- *  To produce the reverse order, the following can also be used
- *  (and may be faster):
+ *    a = [3, 2, 0, 1]
+ *    a.sort {|a, b| a <=> b } # => [0, 1, 2, 3]
+ *    a.sort {|a, b| b <=> a } # => [3, 2, 1, 0]
  *
- *    ary.sort.reverse!             #=> ["e", "d", "c", "b", "a"]
+ *  When the block returns zero, the order for +a+ and +b+ is indeterminate,
+ *  and may be unstable.
  *
- *  See also Enumerable#sort_by.
+ *  See an example in Numeric#nonzero? for the idiom to sort more
+ *  complex structure.
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -2880,55 +3617,15 @@ static VALUE rb_ary_bsearch_index(VALUE ary);
 
 /*
  *  call-seq:
- *     ary.bsearch {|x| block }  -> elem
- *
- *  By using binary search, finds a value from this array which meets
- *  the given condition in O(log n) where n is the size of the array.
- *
- *  You can use this method in two modes: a find-minimum mode and
- *  a find-any mode.  In either case, the elements of the array must be
- *  monotone (or sorted) with respect to the block.
- *
- *  In find-minimum mode (this is a good choice for typical use cases),
- *  the block must always return true or false, and there must be an index i
- *  (0 <= i <= ary.size) so that:
- *
- *  - the block returns false for any element whose index is less than
- *    i, and
- *  - the block returns true for any element whose index is greater
- *    than or equal to i.
- *
- *  This method returns the i-th element.  If i is equal to ary.size,
- *  it returns nil.
- *
- *     ary = [0, 4, 7, 10, 12]
- *     ary.bsearch {|x| x >=   4 } #=> 4
- *     ary.bsearch {|x| x >=   6 } #=> 7
- *     ary.bsearch {|x| x >=  -1 } #=> 0
- *     ary.bsearch {|x| x >= 100 } #=> nil
- *
- *  In find-any mode (this behaves like libc's bsearch(3)), the block
- *  must always return a number, and there must be two indices i and j
- *  (0 <= i <= j <= ary.size) so that:
- *
- *  - the block returns a positive number for ary[k] if 0 <= k < i,
- *  - the block returns zero for ary[k] if i <= k < j, and
- *  - the block returns a negative number for ary[k] if
- *    j <= k < ary.size.
- *
- *  Under this condition, this method returns any element whose index
- *  is within i...j.  If i is equal to j (i.e., there is no element
- *  that satisfies the block), this method returns nil.
- *
- *     ary = [0, 4, 7, 10, 12]
- *     # try to find v such that 4 <= v < 8
- *     ary.bsearch {|x| 1 - x / 4 } #=> 4 or 7
- *     # try to find v such that 8 <= v < 10
- *     ary.bsearch {|x| 4 - x / 2 } #=> nil
- *
- *  You must not mix the two modes at a time; the block must always
- *  return either true/false, or always return a number.  It is
- *  undefined which value is actually picked up at each iteration.
+ *    bsearch {|element| ... } -> found_element or nil
+ *    bsearch -> new_enumerator
+ *
+ *  Returns the element from +self+ found by a binary search,
+ *  or +nil+ if the search found no suitable element.
+ *
+ *  See {Binary Searching}[rdoc-ref:language/bsearch.rdoc].
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -2937,22 +3634,22 @@ rb_ary_bsearch(VALUE ary)
     VALUE index_result = rb_ary_bsearch_index(ary);
 
     if (FIXNUM_P(index_result)) {
-	return rb_ary_entry(ary, FIX2LONG(index_result));
+        return rb_ary_entry(ary, FIX2LONG(index_result));
     }
     return index_result;
 }
 
 /*
  *  call-seq:
- *     ary.bsearch_index {|x| block }  -> int or nil
+ *    bsearch_index {|element| ... } -> integer or nil
+ *    bsearch_index -> new_enumerator
+ *
+ *  Returns the integer index of the element from +self+ found by a binary search,
+ *  or +nil+ if the search found no suitable element.
  *
- *  By using binary search, finds an index of a value from this array which
- *  meets the given condition in O(log n) where n is the size of the array.
+ *  See {Binary Searching}[rdoc-ref:language/bsearch.rdoc].
  *
- *  It supports two modes, depending on the nature of the block. They are
- *  exactly the same as in the case of the #bsearch method, with the only difference
- *  being that this method returns the index of the element instead of the
- *  element itself. For more details consult the documentation for #bsearch.
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -2964,39 +3661,39 @@ rb_ary_bsearch_index(VALUE ary)
 
     RETURN_ENUMERATOR(ary, 0, 0);
     while (low < high) {
-	mid = low + ((high - low) / 2);
-	val = rb_ary_entry(ary, mid);
-	v = rb_yield(val);
-	if (FIXNUM_P(v)) {
-	    if (v == INT2FIX(0)) return INT2FIX(mid);
-	    smaller = (SIGNED_VALUE)v < 0; /* Fixnum preserves its sign-bit */
-	}
-	else if (v == Qtrue) {
-	    satisfied = 1;
-	    smaller = 1;
-	}
-	else if (v == Qfalse || v == Qnil) {
-	    smaller = 0;
-	}
-	else if (rb_obj_is_kind_of(v, rb_cNumeric)) {
-	    const VALUE zero = INT2FIX(0);
-	    switch (rb_cmpint(rb_funcallv(v, id_cmp, 1, &zero), v, zero)) {
-	      case 0: return INT2FIX(mid);
-	      case 1: smaller = 1; break;
-	      case -1: smaller = 0;
-	    }
-	}
-	else {
-	    rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE
-		     " (must be numeric, true, false or nil)",
-		     rb_obj_class(v));
-	}
-	if (smaller) {
-	    high = mid;
-	}
-	else {
-	    low = mid + 1;
-	}
+        mid = low + ((high - low) / 2);
+        val = rb_ary_entry(ary, mid);
+        v = rb_yield(val);
+        if (FIXNUM_P(v)) {
+            if (v == INT2FIX(0)) return INT2FIX(mid);
+            smaller = (SIGNED_VALUE)v < 0; /* Fixnum preserves its sign-bit */
+        }
+        else if (v == Qtrue) {
+            satisfied = 1;
+            smaller = 1;
+        }
+        else if (!RTEST(v)) {
+            smaller = 0;
+        }
+        else if (rb_obj_is_kind_of(v, rb_cNumeric)) {
+            const VALUE zero = INT2FIX(0);
+            switch (rb_cmpint(rb_funcallv(v, id_cmp, 1, &zero), v, zero)) {
+              case 0: return INT2FIX(mid);
+              case 1: smaller = 0; break;
+              case -1: smaller = 1;
+            }
+        }
+        else {
+            rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE
+                     " (must be numeric, true, false or nil)",
+                     rb_obj_class(v));
+        }
+        if (smaller) {
+            high = mid;
+        }
+        else {
+            low = mid + 1;
+        }
     }
     if (!satisfied) return Qnil;
     return INT2FIX(low);
@@ -3011,18 +3708,24 @@ sort_by_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, dummy))
 
 /*
  *  call-seq:
- *     ary.sort_by! {|obj| block}      -> ary
- *     ary.sort_by!                    -> Enumerator
+ *    sort_by! {|element| ... } -> self
+ *    sort_by! -> new_enumerator
+ *
+ *  With a block given, sorts the elements of +self+ in place;
+ *  returns self.
+ *
+ *  Calls the block with each successive element;
+ *  sorts elements based on the values returned from the block:
  *
- *  Sorts +self+ in place using a set of keys generated by mapping the
- *  values in +self+ through the given block.
+ *    a = ['aaaa', 'bbb', 'cc', 'd']
+ *    a.sort_by! {|element| element.size }
+ *    a # => ["d", "cc", "bbb", "aaaa"]
  *
- *  The result is not guaranteed to be stable.  When two keys are equal,
- *  the order of the corresponding elements is unpredictable.
+ *  For duplicate values returned by the block, the ordering is indeterminate, and may be unstable.
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With no block given, returns a new Enumerator.
  *
- *  See also Enumerable#sort_by.
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -3032,31 +3735,32 @@ rb_ary_sort_by_bang(VALUE ary)
 
     RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
     rb_ary_modify(ary);
-    sorted = rb_block_call(ary, rb_intern("sort_by"), 0, 0, sort_by_i, 0);
-    rb_ary_replace(ary, sorted);
+    if (RARRAY_LEN(ary) > 1) {
+        sorted = rb_block_call(ary, rb_intern("sort_by"), 0, 0, sort_by_i, 0);
+        rb_ary_replace(ary, sorted);
+    }
     return ary;
 }
 
 
 /*
  *  call-seq:
- *     ary.collect {|item| block}    -> new_ary
- *     ary.map     {|item| block}    -> new_ary
- *     ary.collect                   -> Enumerator
- *     ary.map                       -> Enumerator
- *
- *  Invokes the given block once for each element of +self+.
+ *    collect {|element| ... } -> new_array
+ *    collect -> new_enumerator
+ *    map {|element| ... } -> new_array
+ *    map -> new_enumerator
  *
- *  Creates a new array containing the values returned by the block.
+ *  With a block given, calls the block with each element of +self+;
+ *  returns a new array whose elements are the return values from the block:
  *
- *  See also Enumerable#collect.
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.map {|element| element.class }
+ *    a1 # => [Symbol, String, Integer]
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With no block given, returns a new Enumerator.
  *
- *     a = [ "a", "b", "c", "d" ]
- *     a.collect {|x| x + "!"}           #=> ["a!", "b!", "c!", "d!"]
- *     a.map.with_index {|x, i| x * i}   #=> ["", "b", "cc", "ddd"]
- *     a                                 #=> ["a", "b", "c", "d"]
+ *  Related: #collect!;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3076,23 +3780,22 @@ rb_ary_collect(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.collect! {|item| block }   -> ary
- *     ary.map!     {|item| block }   -> ary
- *     ary.collect!                   -> Enumerator
- *     ary.map!                       -> Enumerator
+ *    collect! {|element| ... } -> self
+ *    collect! -> new_enumerator
+ *    map! {|element| ... } -> self
+ *    map! -> new_enumerator
  *
- *  Invokes the given block once for each element of +self+, replacing the
- *  element with the value returned by the block.
+ *  With a block given, calls the block with each element of +self+
+ *  and replaces the element with the block's return value;
+ *  returns +self+:
  *
- *  See also Enumerable#collect.
+ *    a = [:foo, 'bar', 2]
+ *    a.map! { |element| element.class } # => [Symbol, String, Integer]
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With no block given, returns a new Enumerator.
  *
- *     a = [ "a", "b", "c", "d" ]
- *     a.map! {|x| x + "!" }
- *     a #=>  [ "a!", "b!", "c!", "d!" ]
- *     a.collect!.with_index {|x, i| x[0...i] }
- *     a #=>  ["", "b", "c!", "d!"]
+ *  Related: #collect;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3103,7 +3806,7 @@ rb_ary_collect_bang(VALUE ary)
     RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
     rb_ary_modify(ary);
     for (i = 0; i < RARRAY_LEN(ary); i++) {
-	rb_ary_store(ary, i, rb_yield(RARRAY_AREF(ary, i)));
+        rb_ary_store(ary, i, rb_yield(RARRAY_AREF(ary, i)));
     }
     return ary;
 }
@@ -3115,21 +3818,21 @@ rb_get_values_at(VALUE obj, long olen, int argc, const VALUE *argv, VALUE (*func
     long beg, len, i, j;
 
     for (i=0; i<argc; i++) {
-	if (FIXNUM_P(argv[i])) {
-	    rb_ary_push(result, (*func)(obj, FIX2LONG(argv[i])));
-	    continue;
-	}
-	/* check if idx is Range */
-	if (rb_range_beg_len(argv[i], &beg, &len, olen, 1)) {
-	    long end = olen < beg+len ? olen : beg+len;
-	    for (j = beg; j < end; j++) {
-		rb_ary_push(result, (*func)(obj, j));
-	    }
-	    if (beg + len > j)
-		rb_ary_resize(result, RARRAY_LEN(result) + (beg + len) - j);
-	    continue;
-	}
-	rb_ary_push(result, (*func)(obj, NUM2LONG(argv[i])));
+        if (FIXNUM_P(argv[i])) {
+            rb_ary_push(result, (*func)(obj, FIX2LONG(argv[i])));
+            continue;
+        }
+        /* check if idx is Range */
+        if (rb_range_beg_len(argv[i], &beg, &len, olen, 1)) {
+            long end = olen < beg+len ? olen : beg+len;
+            for (j = beg; j < end; j++) {
+                rb_ary_push(result, (*func)(obj, j));
+            }
+            if (beg + len > j)
+                rb_ary_resize(result, RARRAY_LEN(result) + (beg + len) - j);
+            continue;
+        }
+        rb_ary_push(result, (*func)(obj, NUM2LONG(argv[i])));
     }
     return result;
 }
@@ -3139,45 +3842,133 @@ append_values_at_single(VALUE result, VALUE ary, long olen, VALUE idx)
 {
     long beg, len;
     if (FIXNUM_P(idx)) {
-	beg = FIX2LONG(idx);
+        beg = FIX2LONG(idx);
     }
     /* check if idx is Range */
     else if (rb_range_beg_len(idx, &beg, &len, olen, 1)) {
-	if (len > 0) {
-            const VALUE *const src = RARRAY_CONST_PTR_TRANSIENT(ary);
-	    const long end = beg + len;
-	    const long prevlen = RARRAY_LEN(result);
-	    if (beg < olen) {
-		rb_ary_cat(result, src + beg, end > olen ? olen-beg : len);
-	    }
-	    if (end > olen) {
-		rb_ary_store(result, prevlen + len - 1, Qnil);
-	    }
-	}
-	return result;
+        if (len > 0) {
+            const VALUE *const src = RARRAY_CONST_PTR(ary);
+            const long end = beg + len;
+            const long prevlen = RARRAY_LEN(result);
+            if (beg < olen) {
+                rb_ary_cat(result, src + beg, end > olen ? olen-beg : len);
+            }
+            if (end > olen) {
+                rb_ary_store(result, prevlen + len - 1, Qnil);
+            }
+        }
+        return result;
     }
     else {
-	beg = NUM2LONG(idx);
+        beg = NUM2LONG(idx);
     }
     return rb_ary_push(result, rb_ary_entry(ary, beg));
 }
 
 /*
  *  call-seq:
- *     ary.values_at(selector, ...)  -> new_ary
+ *    values_at(*specifiers) -> new_array
+ *
+ *  Returns elements from +self+ in a new array; does not modify +self+.
+ *
+ *  The objects included in the returned array are the elements of +self+
+ *  selected by the given +specifiers+,
+ *  each of which must be a numeric index or a Range.
+ *
+ *  In brief:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *
+ *    # Index specifiers.
+ *    a.values_at(2, 0, 2, 0)     # => ["c", "a", "c", "a"] # May repeat.
+ *    a.values_at(-4, -3, -2, -1) # => ["a", "b", "c", "d"] # Counts backwards if negative.
+ *    a.values_at(-50, 50)        # => [nil, nil]           # Outside of self.
+ *
+ *    # Range specifiers.
+ *    a.values_at(1..3)       # => ["b", "c", "d"] # From range.begin to range.end.
+ *    a.values_at(1...3)      # => ["b", "c"]      # End excluded.
+ *    a.values_at(3..1)       # => []              # No such elements.
+ *
+ *    a.values_at(-3..3)  # => ["b", "c", "d"]     # Negative range.begin counts backwards.
+ *    a.values_at(-50..3)                          # Raises RangeError.
+ *
+ *    a.values_at(1..-2)  # => ["b", "c"]          # Negative range.end counts backwards.
+ *    a.values_at(1..-50) # => []                  # No such elements.
+ *
+ *    # Mixture of specifiers.
+ *    a.values_at(2..3, 3, 0..1, 0) # => ["c", "d", "d", "a", "b", "a"]
+ *
+ *  With no +specifiers+ given, returns a new empty array:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.values_at # => []
+ *
+ *  For each numeric specifier +index+, includes an element:
+ *
+ *  - For each non-negative numeric specifier +index+ that is in-range (less than <tt>self.size</tt>),
+ *    includes the element at offset +index+:
+ *
+ *      a.values_at(0, 2)     # => ["a", "c"]
+ *      a.values_at(0.1, 2.9) # => ["a", "c"]
  *
- *  Returns an array containing the elements in +self+ corresponding to the
- *  given +selector+(s).
+ *  - For each negative numeric +index+ that is in-range (greater than or equal to <tt>- self.size</tt>),
+ *    counts backwards from the end of +self+:
  *
- *  The selectors may be either integer indices or ranges.
+ *      a.values_at(-1, -4) # => ["d", "a"]
  *
- *  See also Array#select.
+ *  The given indexes may be in any order, and may repeat:
  *
- *     a = %w{ a b c d e f }
- *     a.values_at(1, 3, 5)          # => ["b", "d", "f"]
- *     a.values_at(1, 3, 5, 7)       # => ["b", "d", "f", nil]
- *     a.values_at(-1, -2, -2, -7)   # => ["f", "e", "e", nil]
- *     a.values_at(4..6, 3...6)      # => ["e", "f", nil, "d", "e", "f"]
+ *    a.values_at(2, 0, 1, 0, 2) # => ["c", "a", "b", "a", "c"]
+ *
+ *  For each +index+ that is out-of-range, includes +nil+:
+ *
+ *    a.values_at(4, -5) # => [nil, nil]
+ *
+ *  For each Range specifier +range+, includes elements
+ *  according to <tt>range.begin</tt> and <tt>range.end</tt>:
+ *
+ *  - If both <tt>range.begin</tt> and <tt>range.end</tt>
+ *    are non-negative and in-range (less than <tt>self.size</tt>),
+ *    includes elements from index <tt>range.begin</tt>
+ *    through <tt>range.end - 1</tt> (if <tt>range.exclude_end?</tt>),
+ *    or through <tt>range.end</tt> (otherwise):
+ *
+ *      a.values_at(1..2)  # => ["b", "c"]
+ *      a.values_at(1...2) # => ["b"]
+ *
+ *  - If <tt>range.begin</tt> is negative and in-range (greater than or equal to <tt>- self.size</tt>),
+ *    counts backwards from the end of +self+:
+ *
+ *      a.values_at(-2..3) # => ["c", "d"]
+ *
+ *  - If <tt>range.begin</tt> is negative and out-of-range, raises an exception:
+ *
+ *      a.values_at(-5..3) # Raises RangeError.
+ *
+ *  - If <tt>range.end</tt> is positive and out-of-range,
+ *    extends the returned array with +nil+ elements:
+ *
+ *      a.values_at(1..5) # => ["b", "c", "d", nil, nil]
+ *
+ *  - If <tt>range.end</tt> is negative and in-range,
+ *    counts backwards from the end of +self+:
+ *
+ *      a.values_at(1..-2) # => ["b", "c"]
+ *
+ *  - If <tt>range.end</tt> is negative and out-of-range,
+ *    returns an empty array:
+ *
+ *      a.values_at(1..-5) # => []
+ *
+ *  The given ranges may be in any order and may repeat:
+ *
+ *    a.values_at(2..3, 0..1, 2..3) # => ["c", "d", "a", "b", "c", "d"]
+ *
+ *  The given specifiers may be any mixture of indexes and ranges:
+ *
+ *    a.values_at(3, 1..2, 0, 2..3) # => ["d", "b", "c", "a", "c", "d"]
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3186,7 +3977,7 @@ rb_ary_values_at(int argc, VALUE *argv, VALUE ary)
     long i, olen = RARRAY_LEN(ary);
     VALUE result = rb_ary_new_capa(argc);
     for (i = 0; i < argc; ++i) {
-	append_values_at_single(result, ary, olen, argv[i]);
+        append_values_at_single(result, ary, olen, argv[i]);
     }
     RB_GC_GUARD(ary);
     return result;
@@ -3195,24 +3986,22 @@ rb_ary_values_at(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.select {|item| block}   -> new_ary
- *     ary.select                  -> Enumerator
- *     ary.filter {|item| block}   -> new_ary
- *     ary.filter                  -> Enumerator
- *
- *  Returns a new array containing all elements of +ary+
- *  for which the given +block+ returns a true value.
+ *    select {|element| ... } -> new_array
+ *    select -> new_enumerator
+ *    filter {|element| ... } -> new_array
+ *    filter -> new_enumerator
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With a block given, calls the block with each element of +self+;
+ *  returns a new array containing those elements of +self+
+ *  for which the block returns a truthy value:
  *
- *     [1,2,3,4,5].select {|num| num.even? }     #=> [2, 4]
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.select {|element| element.to_s.start_with?('b') }
+ *    # => ["bar", :bam]
  *
- *     a = %w[ a b c d e f ]
- *     a.select {|v| v =~ /[aeiou]/ }    #=> ["a", "e"]
+ *  With no block given, returns a new Enumerator.
  *
- *  See also Enumerable#select.
- *
- *  Array#filter is an alias for Array#select.
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3224,9 +4013,9 @@ rb_ary_select(VALUE ary)
     RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
     result = rb_ary_new2(RARRAY_LEN(ary));
     for (i = 0; i < RARRAY_LEN(ary); i++) {
-	if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
-	    rb_ary_push(result, rb_ary_elt(ary, i));
-	}
+        if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
+            rb_ary_push(result, rb_ary_elt(ary, i));
+        }
     }
     return result;
 }
@@ -3244,12 +4033,12 @@ select_bang_i(VALUE a)
     long i1, i2;
 
     for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); arg->len[0] = ++i1) {
-	VALUE v = RARRAY_AREF(ary, i1);
-	if (!RTEST(rb_yield(v))) continue;
-	if (i1 != i2) {
-	    rb_ary_store(ary, i2, v);
-	}
-	arg->len[1] = ++i2;
+        VALUE v = RARRAY_AREF(ary, i1);
+        if (!RTEST(rb_yield(v))) continue;
+        if (i1 != i2) {
+            rb_ary_store(ary, i2, v);
+        }
+        arg->len[1] = ++i2;
     }
     return (i1 == i2) ? Qnil : ary;
 }
@@ -3263,37 +4052,39 @@ select_bang_ensure(VALUE a)
     long i1 = arg->len[0], i2 = arg->len[1];
 
     if (i2 < len && i2 < i1) {
-	long tail = 0;
-	if (i1 < len) {
-	    tail = len - i1;
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-		    MEMMOVE(ptr + i2, ptr + i1, VALUE, tail);
-		});
-	}
-	ARY_SET_LEN(ary, i2 + tail);
+        long tail = 0;
+        rb_ary_modify(ary);
+        if (i1 < len) {
+            tail = len - i1;
+            RARRAY_PTR_USE(ary, ptr, {
+                    MEMMOVE(ptr + i2, ptr + i1, VALUE, tail);
+                });
+        }
+        ARY_SET_LEN(ary, i2 + tail);
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.select! {|item| block } -> ary or nil
- *     ary.select!                 -> Enumerator
- *     ary.filter! {|item| block } -> ary or nil
- *     ary.filter!                 -> Enumerator
+ *    select! {|element| ... } -> self or nil
+ *    select! -> new_enumerator
+ *    filter! {|element| ... } -> self or nil
+ *    filter! -> new_enumerator
  *
- *  Invokes the given block passing in successive elements from +self+,
- *  deleting elements for which the block returns a +false+ value.
+ *  With a block given, calls the block with each element of +self+;
+ *  removes from +self+ those elements for which the block returns +false+ or +nil+.
  *
- *  The array may not be changed instantly every time the block is called.
+ *  Returns +self+ if any elements were removed:
  *
- *  If changes were made, it will return +self+, otherwise it returns +nil+.
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.select! {|element| element.to_s.start_with?('b') } # => ["bar", :bam]
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  Returns +nil+ if no elements were removed.
  *
- *  See also Array#keep_if.
+ *  With no block given, returns a new Enumerator.
  *
- *  Array#filter! is an alias for Array#select!.
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3311,19 +4102,18 @@ rb_ary_select_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.keep_if {|item| block}   -> ary
- *     ary.keep_if                  -> Enumerator
+ *    keep_if {|element| ... } -> self
+ *    keep_if -> new_enumerator
  *
- *  Deletes every element of +self+ for which the given block evaluates to
- *  +false+, and returns +self+.
+ *  With a block given, calls the block with each element of +self+;
+ *  removes the element from +self+ if the block does not return a truthy value:
  *
- *  If no block is given, an Enumerator is returned instead.
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.keep_if {|element| element.to_s.start_with?('b') } # => ["bar", :bam]
  *
- *     a = %w[ a b c d e f ]
- *     a.keep_if {|v| v =~ /[aeiou]/ }    #=> ["a", "e"]
- *     a                                  #=> ["a", "e"]
+ *  With no block given, returns a new Enumerator.
  *
- *  See also Array#select!.
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3339,32 +4129,49 @@ ary_resize_smaller(VALUE ary, long len)
 {
     rb_ary_modify(ary);
     if (RARRAY_LEN(ary) > len) {
-	ARY_SET_LEN(ary, len);
-	if (len * 2 < ARY_CAPA(ary) &&
-	    ARY_CAPA(ary) > ARY_DEFAULT_SIZE) {
-	    ary_resize_capa(ary, len * 2);
-	}
+        ARY_SET_LEN(ary, len);
+        if (len * 2 < ARY_CAPA(ary) &&
+            ARY_CAPA(ary) > ARY_DEFAULT_SIZE) {
+            ary_resize_capa(ary, len * 2);
+        }
     }
 }
 
 /*
  *  call-seq:
- *     ary.delete(obj)            -> item or nil
- *     ary.delete(obj) {block}    -> item or result of block
+ *    delete(object) -> last_removed_object
+ *    delete(object) {|element| ... } -> last_removed_object or block_return
+ *
+ *  Removes zero or more elements from +self+.
+ *
+ *  With no block given,
+ *  removes from +self+ each element +ele+ such that <tt>ele == object</tt>;
+ *  returns the last removed element:
+ *
+ *    a = [0, 1, 2, 2.0]
+ *    a.delete(2) # => 2.0
+ *    a           # => [0, 1]
  *
- *  Deletes all items from +self+ that are equal to +obj+.
+ *  Returns +nil+ if no elements removed:
  *
- *  Returns the last deleted item, or +nil+ if no matching item is found.
+ *    a.delete(2) # => nil
  *
- *  If the optional code block is given, the result of the block is returned if
- *  the item is not found.  (To remove +nil+ elements and get an informative
- *  return value, use Array#compact!)
+ *  With a block given,
+ *  removes from +self+ each element +ele+ such that <tt>ele == object</tt>.
  *
- *     a = [ "a", "b", "b", "b", "c" ]
- *     a.delete("b")                   #=> "b"
- *     a                               #=> ["a", "c"]
- *     a.delete("z")                   #=> nil
- *     a.delete("z") {"not found"}     #=> "not found"
+ *  If any such elements are found, ignores the block
+ *  and returns the last removed element:
+ *
+ *    a = [0, 1, 2, 2.0]
+ *    a.delete(2) {|element| fail 'Cannot happen' } # => 2.0
+ *    a                                             # => [0, 1]
+ *
+ *  If no such element is found, returns the block's return value:
+ *
+ *    a.delete(2) {|element| "Element #{element} not found." }
+ *    # => "Element 2 not found."
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 VALUE
@@ -3374,22 +4181,22 @@ rb_ary_delete(VALUE ary, VALUE item)
     long i1, i2;
 
     for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
-	VALUE e = RARRAY_AREF(ary, i1);
+        VALUE e = RARRAY_AREF(ary, i1);
 
-	if (rb_equal(e, item)) {
-	    v = e;
-	    continue;
-	}
-	if (i1 != i2) {
-	    rb_ary_store(ary, i2, e);
-	}
-	i2++;
+        if (rb_equal(e, item)) {
+            v = e;
+            continue;
+        }
+        if (i1 != i2) {
+            rb_ary_store(ary, i2, e);
+        }
+        i2++;
     }
     if (RARRAY_LEN(ary) == i2) {
-	if (rb_block_given_p()) {
-	    return rb_yield(item);
-	}
-	return Qnil;
+        if (rb_block_given_p()) {
+            return rb_yield(item);
+        }
+        return Qnil;
     }
 
     ary_resize_smaller(ary, i2);
@@ -3404,18 +4211,18 @@ rb_ary_delete_same(VALUE ary, VALUE item)
     long i1, i2;
 
     for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
-	VALUE e = RARRAY_AREF(ary, i1);
+        VALUE e = RARRAY_AREF(ary, i1);
 
-	if (e == item) {
-	    continue;
-	}
-	if (i1 != i2) {
-	    rb_ary_store(ary, i2, e);
-	}
-	i2++;
+        if (e == item) {
+            continue;
+        }
+        if (i1 != i2) {
+            rb_ary_store(ary, i2, e);
+        }
+        i2++;
     }
     if (RARRAY_LEN(ary) == i2) {
-	return;
+        return;
     }
 
     ary_resize_smaller(ary, i2);
@@ -3429,13 +4236,13 @@ rb_ary_delete_at(VALUE ary, long pos)
 
     if (pos >= len) return Qnil;
     if (pos < 0) {
-	pos += len;
-	if (pos < 0) return Qnil;
+        pos += len;
+        if (pos < 0) return Qnil;
     }
 
     rb_ary_modify(ary);
     del = RARRAY_AREF(ary, pos);
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+    RARRAY_PTR_USE(ary, ptr, {
         MEMMOVE(ptr+pos, ptr+pos+1, VALUE, len-pos-1);
     });
     ARY_INCREASE_LEN(ary, -1);
@@ -3445,17 +4252,30 @@ rb_ary_delete_at(VALUE ary, long pos)
 
 /*
  *  call-seq:
- *     ary.delete_at(index)  -> obj or nil
+ *    delete_at(index) -> removed_object or nil
  *
- *  Deletes the element at the specified +index+, returning that element, or
- *  +nil+ if the +index+ is out of range.
+ *  Removes the element of +self+ at the given +index+, which must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
  *
- *  See also Array#slice!
+ *  When +index+ is non-negative, deletes the element at offset +index+:
  *
- *     a = ["ant", "bat", "cat", "dog"]
- *     a.delete_at(2)    #=> "cat"
- *     a                 #=> ["ant", "bat", "dog"]
- *     a.delete_at(99)   #=> nil
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_at(1) # => "bar"
+ *    a # => [:foo, 2]
+ *
+ *  When +index+ is negative, counts backward from the end of the array:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_at(-2) # => "bar"
+ *    a # => [:foo, 2]
+ *
+ *  When +index+ is out of range, returns +nil+.
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_at(3)  # => nil
+ *    a.delete_at(-4) # => nil
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3464,70 +4284,156 @@ rb_ary_delete_at_m(VALUE ary, VALUE pos)
     return rb_ary_delete_at(ary, NUM2LONG(pos));
 }
 
+static VALUE
+ary_slice_bang_by_rb_ary_splice(VALUE ary, long pos, long len)
+{
+    const long orig_len = RARRAY_LEN(ary);
+
+    if (len < 0) {
+        return Qnil;
+    }
+    else if (pos < -orig_len) {
+        return Qnil;
+    }
+    else if (pos < 0) {
+        pos += orig_len;
+    }
+    else if (orig_len < pos) {
+        return Qnil;
+    }
+    if (orig_len < pos + len) {
+        len = orig_len - pos;
+    }
+    if (len == 0) {
+        return rb_ary_new2(0);
+    }
+    else {
+        VALUE arg2 = rb_ary_new4(len, RARRAY_CONST_PTR(ary)+pos);
+        rb_ary_splice(ary, pos, len, 0, 0);
+        return arg2;
+    }
+}
+
 /*
  *  call-seq:
- *     ary.slice!(index)         -> obj or nil
- *     ary.slice!(start, length) -> new_ary or nil
- *     ary.slice!(range)         -> new_ary or nil
- *
- *  Deletes the element(s) given by an +index+ (optionally up to +length+
- *  elements) or by a +range+.
- *
- *  Returns the deleted object (or objects), or +nil+ if the +index+ is out of
- *  range.
- *
- *     a = [ "a", "b", "c" ]
- *     a.slice!(1)     #=> "b"
- *     a               #=> ["a", "c"]
- *     a.slice!(-1)    #=> "c"
- *     a               #=> ["a"]
- *     a.slice!(100)   #=> nil
- *     a               #=> ["a"]
+ *    slice!(index) -> object or nil
+ *    slice!(start, length) -> new_array or nil
+ *    slice!(range) -> new_array or nil
+ *
+ *  Removes and returns elements from +self+.
+ *
+ *  With numeric argument +index+ given,
+ *  removes and returns the element at offset +index+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(2)   # => "c"
+ *    a             # => ["a", "b", "d"]
+ *    a.slice!(2.1) # => "d"
+ *    a             # => ["a", "b"]
+ *
+ *  If +index+ is negative, counts backwards from the end of +self+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(-2) # => "c"
+ *    a            # => ["a", "b", "d"]
+ *
+ *  If +index+ is out of range, returns +nil+.
+ *
+ *  With numeric arguments +start+ and +length+ given,
+ *  removes +length+ elements from +self+ beginning at zero-based offset +start+;
+ *  returns the removed objects in a new array:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(1, 2)     # => ["b", "c"]
+ *    a                  # => ["a", "d"]
+ *    a.slice!(0.1, 1.1) # => ["a"]
+ *    a                  # => ["d"]
+ *
+ *  If +start+ is negative, counts backwards from the end of +self+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(-2, 1) # => ["c"]
+ *    a               # => ["a", "b", "d"]
+ *
+ *  If +start+ is out-of-range, returns +nil+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(5, 1)  # => nil
+ *    a.slice!(-5, 1) # => nil
+ *
+ *  If <tt>start + length</tt> exceeds the array size,
+ *  removes and returns all elements from offset +start+ to the end:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(2, 50) # => ["c", "d"]
+ *    a               # => ["a", "b"]
+ *
+ *  If <tt>start == a.size</tt> and +length+ is non-negative,
+ *  returns a new empty array.
+ *
+ *  If +length+ is negative, returns +nil+.
+ *
+ *  With Range argument +range+ given,
+ *  treats <tt>range.min</tt> as +start+ (as above)
+ *  and <tt>range.size</tt> as +length+ (as above):
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(1..2) # => ["b", "c"]
+ *    a              # => ["a", "d"]
+ *
+ *  If <tt>range.start == a.size</tt>, returns a new empty array:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(4..5) # => []
+ *
+ *  If <tt>range.start</tt> is larger than the array size, returns +nil+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+      a.slice!(5..6) # => nil
+ *
+ *  If <tt>range.start</tt> is negative,
+ *  calculates the start index by counting backwards from the end of +self+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(-2..2) # => ["c"]
+ *
+ *  If <tt>range.end</tt> is negative,
+ *  calculates the end index by counting backwards from the end of +self+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(0..-2) # => ["a", "b", "c"]
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
 rb_ary_slice_bang(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE arg1, arg2;
-    long pos, len, orig_len;
+    VALUE arg1;
+    long pos, len;
 
     rb_ary_modify_check(ary);
-    if (argc == 2) {
-	pos = NUM2LONG(argv[0]);
-	len = NUM2LONG(argv[1]);
-      delete_pos_len:
-	if (len < 0) return Qnil;
-	orig_len = RARRAY_LEN(ary);
-	if (pos < 0) {
-	    pos += orig_len;
-	    if (pos < 0) return Qnil;
-	}
-	else if (orig_len < pos) return Qnil;
-	if (orig_len < pos + len) {
-	    len = orig_len - pos;
-	}
-	if (len == 0) return rb_ary_new2(0);
-        arg2 = rb_ary_new4(len, RARRAY_CONST_PTR_TRANSIENT(ary)+pos);
-	RBASIC_SET_CLASS(arg2, rb_obj_class(ary));
-	rb_ary_splice(ary, pos, len, 0, 0);
-	return arg2;
-    }
-
     rb_check_arity(argc, 1, 2);
     arg1 = argv[0];
 
+    if (argc == 2) {
+        pos = NUM2LONG(argv[0]);
+        len = NUM2LONG(argv[1]);
+        return ary_slice_bang_by_rb_ary_splice(ary, pos, len);
+    }
+
     if (!FIXNUM_P(arg1)) {
-	switch (rb_range_beg_len(arg1, &pos, &len, RARRAY_LEN(ary), 0)) {
-	  case Qtrue:
-	    /* valid range */
-	    goto delete_pos_len;
-	  case Qnil:
-	    /* invalid range */
-	    return Qnil;
-	  default:
-	    /* not a range */
-	    break;
-	}
+        switch (rb_range_beg_len(arg1, &pos, &len, RARRAY_LEN(ary), 0)) {
+          case Qtrue:
+            /* valid range */
+            return ary_slice_bang_by_rb_ary_splice(ary, pos, len);
+          case Qnil:
+            /* invalid range */
+            return Qnil;
+          default:
+            /* not a range */
+            break;
+        }
     }
 
     return rb_ary_delete_at(ary, NUM2LONG(arg1));
@@ -3539,11 +4445,11 @@ ary_reject(VALUE orig, VALUE result)
     long i;
 
     for (i = 0; i < RARRAY_LEN(orig); i++) {
-	VALUE v = RARRAY_AREF(orig, i);
+        VALUE v = RARRAY_AREF(orig, i);
 
         if (!RTEST(rb_yield(v))) {
-	    rb_ary_push(result, v);
-	}
+            rb_ary_push(result, v);
+        }
     }
     return result;
 }
@@ -3556,12 +4462,12 @@ reject_bang_i(VALUE a)
     long i1, i2;
 
     for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); arg->len[0] = ++i1) {
-	VALUE v = RARRAY_AREF(ary, i1);
-	if (RTEST(rb_yield(v))) continue;
-	if (i1 != i2) {
-	    rb_ary_store(ary, i2, v);
-	}
-	arg->len[1] = ++i2;
+        VALUE v = RARRAY_AREF(ary, i1);
+        if (RTEST(rb_yield(v))) continue;
+        if (i1 != i2) {
+            rb_ary_store(ary, i2, v);
+        }
+        arg->len[1] = ++i2;
     }
     return (i1 == i2) ? Qnil : ary;
 }
@@ -3578,17 +4484,22 @@ ary_reject_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.reject! {|item| block}    -> ary or nil
- *     ary.reject!                   -> Enumerator
+ *    reject! {|element| ... } -> self or nil
+ *    reject! -> new_enumerator
+ *
+ *  With a block given, calls the block with each element of +self+;
+ *  removes each element for which the block returns a truthy value.
  *
- *  Deletes every element of +self+ for which the block evaluates to +true+,
- *  if no changes were made returns +nil+.
+ *  Returns +self+ if any elements removed:
  *
- *  The array may not be changed instantly every time the block is called.
+ *    a = [:foo, 'bar', 2, 'bat']
+ *    a.reject! {|element| element.to_s.start_with?('b') } # => [:foo, 2]
  *
- *  See also Enumerable#reject and Array#delete_if.
+ *  Returns +nil+ if no elements removed.
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3601,15 +4512,19 @@ rb_ary_reject_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.reject  {|item| block }  -> new_ary
- *     ary.reject                   -> Enumerator
+ *    reject {|element| ... } -> new_array
+ *    reject -> new_enumerator
+ *
+ *  With a block given, returns a new array whose elements are all those from +self+
+ *  for which the block returns +false+ or +nil+:
  *
- *  Returns a new array containing the items in +self+ for which the given
- *  block is not +true+. The ordering of non-rejected elements is maintained.
+ *    a = [:foo, 'bar', 2, 'bat']
+ *    a1 = a.reject {|element| element.to_s.start_with?('b') }
+ *    a1 # => [:foo, 2]
  *
- *  See also Array#delete_if
+ *  With no block given, returns a new Enumerator.
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  Related: {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3625,20 +4540,19 @@ rb_ary_reject(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.delete_if {|item| block}    -> ary
- *     ary.delete_if                   -> Enumerator
- *
- *  Deletes every element of +self+ for which block evaluates to +true+.
+ *    delete_if {|element| ... } -> self
+ *    delete_if -> new_numerator
  *
- *  The array is changed instantly every time the block is called, not after
- *  the iteration is over.
+ *  With a block given, calls the block with each element of +self+;
+ *  removes the element if the block returns a truthy value;
+ *  returns +self+:
  *
- *  See also Array#reject!
+ *    a = [:foo, 'bar', 2, 'bat']
+ *    a.delete_if {|element| element.to_s.start_with?('b') } # => [:foo, 2]
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With no block given, returns a new Enumerator.
  *
- *     scores = [ 97, 42, 75 ]
- *     scores.delete_if {|score| score < 80 }   #=> [97]
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3654,10 +4568,9 @@ static VALUE
 take_i(RB_BLOCK_CALL_FUNC_ARGLIST(val, cbarg))
 {
     VALUE *args = (VALUE *)cbarg;
-    if (args[1] == 0) rb_iter_break();
-    else args[1]--;
     if (argc > 1) val = rb_ary_new4(argc, argv);
     rb_ary_push(args[0], val);
+    if (--args[1] == 0) rb_iter_break();
     return Qnil;
 }
 
@@ -3667,38 +4580,108 @@ take_items(VALUE obj, long n)
     VALUE result = rb_check_array_type(obj);
     VALUE args[2];
 
+    if (n == 0) return result;
     if (!NIL_P(result)) return rb_ary_subseq(result, 0, n);
     result = rb_ary_new2(n);
     args[0] = result; args[1] = (VALUE)n;
-    if (rb_check_block_call(obj, idEach, 0, 0, take_i, (VALUE)args) == Qundef)
-	rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (must respond to :each)",
-		 rb_obj_class(obj));
+    if (UNDEF_P(rb_check_block_call(obj, idEach, 0, 0, take_i, (VALUE)args)))
+        rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (must respond to :each)",
+                 rb_obj_class(obj));
     return result;
 }
 
 
 /*
  *  call-seq:
- *     ary.zip(arg, ...)                  -> new_ary
- *     ary.zip(arg, ...) {|arr| block}    -> nil
- *
- *  Converts any arguments to arrays, then merges elements of +self+ with
- *  corresponding elements from each argument.
- *
- *  This generates a sequence of <code>ary.size</code> _n_-element arrays,
- *  where _n_ is one more than the count of arguments.
- *
- *  If the size of any argument is less than the size of the initial array,
- *  +nil+ values are supplied.
- *
- *  If a block is given, it is invoked for each output +array+, otherwise an
- *  array of arrays is returned.
- *
- *     a = [ 4, 5, 6 ]
- *     b = [ 7, 8, 9 ]
- *     [1, 2, 3].zip(a, b)   #=> [[1, 4, 7], [2, 5, 8], [3, 6, 9]]
- *     [1, 2].zip(a, b)      #=> [[1, 4, 7], [2, 5, 8]]
- *     a.zip([1, 2], [8])    #=> [[4, 1, 8], [5, 2, nil], [6, nil, nil]]
+ *    zip(*other_arrays) -> new_array
+ *    zip(*other_arrays) {|sub_array| ... } -> nil
+ *
+ *  With no block given, combines +self+ with the collection of +other_arrays+;
+ *  returns a new array of sub-arrays:
+ *
+ *    [0, 1].zip(['zero', 'one'], [:zero, :one])
+ *    # => [[0, "zero", :zero], [1, "one", :one]]
+ *
+ *  Returned:
+ *
+ *  - The outer array is of size <tt>self.size</tt>.
+ *  - Each sub-array is of size <tt>other_arrays.size + 1</tt>.
+ *  - The _nth_ sub-array contains (in order):
+ *
+ *    - The _nth_ element of +self+.
+ *    - The _nth_ element of each of the other arrays, as available.
+ *
+ *  Example:
+ *
+ *    a = [0, 1]
+ *    zipped = a.zip(['zero', 'one'], [:zero, :one])
+ *    # => [[0, "zero", :zero], [1, "one", :one]]
+ *    zipped.size       # => 2 # Same size as a.
+ *    zipped.first.size # => 3 # Size of other arrays plus 1.
+ *
+ *  When the other arrays are all the same size as +self+,
+ *  the returned sub-arrays are a rearrangement containing exactly elements of all the arrays
+ *  (including +self+), with no omissions or additions:
+ *
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2, :b3]
+ *    c = [:c0, :c1, :c2, :c3]
+ *    d = a.zip(b, c)
+ *    pp d
+ *    # =>
+ *    [[:a0, :b0, :c0],
+ *     [:a1, :b1, :c1],
+ *     [:a2, :b2, :c2],
+ *     [:a3, :b3, :c3]]
+ *
+ *  When one of the other arrays is smaller than +self+,
+ *  pads the corresponding sub-array with +nil+ elements:
+ *
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2]
+ *    c = [:c0, :c1]
+ *    d = a.zip(b, c)
+ *    pp d
+ *    # =>
+ *    [[:a0, :b0, :c0],
+ *     [:a1, :b1, :c1],
+ *     [:a2, :b2, nil],
+ *     [:a3, nil, nil]]
+ *
+ *  When one of the other arrays is larger than +self+,
+ *  _ignores_ its trailing elements:
+ *
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2, :b3, :b4]
+ *    c = [:c0, :c1, :c2, :c3, :c4, :c5]
+ *    d = a.zip(b, c)
+ *    pp d
+ *    # =>
+ *    [[:a0, :b0, :c0],
+ *     [:a1, :b1, :c1],
+ *     [:a2, :b2, :c2],
+ *     [:a3, :b3, :c3]]
+ *
+ *  With a block given, calls the block with each of the other arrays;
+ *  returns +nil+:
+ *
+ *    d = []
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2, :b3]
+ *    c = [:c0, :c1, :c2, :c3]
+ *    a.zip(b, c) {|sub_array| d.push(sub_array.reverse) } # => nil
+ *    pp d
+ *    # =>
+ *    [[:c0, :b0, :a0],
+ *     [:c1, :b1, :a1],
+ *     [:c2, :b2, :a2],
+ *     [:c3, :b3, :a3]]
+ *
+ *  For an *object* in *other_arrays* that is not actually an array,
+ *  forms the "other array" as <tt>object.to_ary</tt>, if defined,
+ *  or as <tt>object.each.to_a</tt> otherwise.
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3709,51 +4692,51 @@ rb_ary_zip(int argc, VALUE *argv, VALUE ary)
     VALUE result = Qnil;
 
     for (i=0; i<argc; i++) {
-	argv[i] = take_items(argv[i], len);
+        argv[i] = take_items(argv[i], len);
     }
 
     if (rb_block_given_p()) {
-	int arity = rb_block_arity();
-
-	if (arity > 1) {
-	    VALUE work, *tmp;
-
-	    tmp = ALLOCV_N(VALUE, work, argc+1);
-
-	    for (i=0; i<RARRAY_LEN(ary); i++) {
-		tmp[0] = RARRAY_AREF(ary, i);
-		for (j=0; j<argc; j++) {
-		    tmp[j+1] = rb_ary_elt(argv[j], i);
-		}
-		rb_yield_values2(argc+1, tmp);
-	    }
-
-	    if (work) ALLOCV_END(work);
-	}
-	else {
-	    for (i=0; i<RARRAY_LEN(ary); i++) {
-		VALUE tmp = rb_ary_new2(argc+1);
-
-		rb_ary_push(tmp, RARRAY_AREF(ary, i));
-		for (j=0; j<argc; j++) {
-		    rb_ary_push(tmp, rb_ary_elt(argv[j], i));
-		}
-		rb_yield(tmp);
-	    }
-	}
+        int arity = rb_block_arity();
+
+        if (arity > 1) {
+            VALUE work, *tmp;
+
+            tmp = ALLOCV_N(VALUE, work, argc+1);
+
+            for (i=0; i<RARRAY_LEN(ary); i++) {
+                tmp[0] = RARRAY_AREF(ary, i);
+                for (j=0; j<argc; j++) {
+                    tmp[j+1] = rb_ary_elt(argv[j], i);
+                }
+                rb_yield_values2(argc+1, tmp);
+            }
+
+            if (work) ALLOCV_END(work);
+        }
+        else {
+            for (i=0; i<RARRAY_LEN(ary); i++) {
+                VALUE tmp = rb_ary_new2(argc+1);
+
+                rb_ary_push(tmp, RARRAY_AREF(ary, i));
+                for (j=0; j<argc; j++) {
+                    rb_ary_push(tmp, rb_ary_elt(argv[j], i));
+                }
+                rb_yield(tmp);
+            }
+        }
     }
     else {
-	result = rb_ary_new_capa(len);
+        result = rb_ary_new_capa(len);
 
-	for (i=0; i<len; i++) {
-	    VALUE tmp = rb_ary_new_capa(argc+1);
+        for (i=0; i<len; i++) {
+            VALUE tmp = rb_ary_new_capa(argc+1);
 
-	    rb_ary_push(tmp, RARRAY_AREF(ary, i));
-	    for (j=0; j<argc; j++) {
-		rb_ary_push(tmp, rb_ary_elt(argv[j], i));
-	    }
-	    rb_ary_push(result, tmp);
-	}
+            rb_ary_push(tmp, RARRAY_AREF(ary, i));
+            for (j=0; j<argc; j++) {
+                rb_ary_push(tmp, rb_ary_elt(argv[j], i));
+            }
+            rb_ary_push(result, tmp);
+        }
     }
 
     return result;
@@ -3761,15 +4744,17 @@ rb_ary_zip(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.transpose -> new_ary
+ *    transpose -> new_array
  *
- *  Assumes that +self+ is an array of arrays and transposes the rows and
- *  columns.
+ *  Returns a new array that is +self+
+ *  as a {transposed matrix}[https://en.wikipedia.org/wiki/Transpose]:
  *
- *     a = [[1,2], [3,4], [5,6]]
- *     a.transpose   #=> [[1, 3, 5], [2, 4, 6]]
+ *    a = [[:a0, :a1], [:b0, :b1], [:c0, :c1]]
+ *    a.transpose # => [[:a0, :b0, :c0], [:a1, :b1, :c1]]
  *
- *  If the length of the subarrays don't match, an IndexError is raised.
+ *  The elements of +self+ must all be the same size.
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3781,36 +4766,38 @@ rb_ary_transpose(VALUE ary)
     alen = RARRAY_LEN(ary);
     if (alen == 0) return rb_ary_dup(ary);
     for (i=0; i<alen; i++) {
-	tmp = to_ary(rb_ary_elt(ary, i));
-	if (elen < 0) {		/* first element */
-	    elen = RARRAY_LEN(tmp);
-	    result = rb_ary_new2(elen);
-	    for (j=0; j<elen; j++) {
-		rb_ary_store(result, j, rb_ary_new2(alen));
-	    }
-	}
-	else if (elen != RARRAY_LEN(tmp)) {
-	    rb_raise(rb_eIndexError, "element size differs (%ld should be %ld)",
-		     RARRAY_LEN(tmp), elen);
-	}
-	for (j=0; j<elen; j++) {
-	    rb_ary_store(rb_ary_elt(result, j), i, rb_ary_elt(tmp, j));
-	}
+        tmp = to_ary(rb_ary_elt(ary, i));
+        if (elen < 0) {		/* first element */
+            elen = RARRAY_LEN(tmp);
+            result = rb_ary_new2(elen);
+            for (j=0; j<elen; j++) {
+                rb_ary_store(result, j, rb_ary_new2(alen));
+            }
+        }
+        else if (elen != RARRAY_LEN(tmp)) {
+            rb_raise(rb_eIndexError, "element size differs (%ld should be %ld)",
+                     RARRAY_LEN(tmp), elen);
+        }
+        for (j=0; j<elen; j++) {
+            rb_ary_store(rb_ary_elt(result, j), i, rb_ary_elt(tmp, j));
+        }
     }
     return result;
 }
 
 /*
  *  call-seq:
- *     ary.replace(other_ary)  -> ary
- *     ary.initialize_copy(other_ary)	-> ary
+ *    initialize_copy(other_array) -> self
+ *    replace(other_array) -> self
+ *
+ *  Replaces the elements of +self+ with the elements of +other_array+, which must be an
+ *  {array-convertible object}[rdoc-ref:implicit_conversion.rdoc@Array-Convertible+Objects];
+ *  returns +self+:
  *
- *  Replaces the contents of +self+ with the contents of +other_ary+,
- *  truncating or expanding if necessary.
+ *    a = ['a', 'b', 'c']   # => ["a", "b", "c"]
+ *    a.replace(['d', 'e']) # => ["d", "e"]
  *
- *     a = [ "a", "b", "c", "d", "e" ]
- *     a.replace([ "x", "y", "z" ])   #=> ["x", "y", "z"]
- *     a                              #=> ["x", "y", "z"]
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
@@ -3820,35 +4807,39 @@ rb_ary_replace(VALUE copy, VALUE orig)
     orig = to_ary(orig);
     if (copy == orig) return copy;
 
-    if (RARRAY_LEN(orig) <= RARRAY_EMBED_LEN_MAX) {
-        VALUE shared_root = 0;
+    rb_ary_reset(copy);
 
-        if (ARY_OWNS_HEAP_P(copy)) {
-            ary_heap_free(copy);
-	}
-        else if (ARY_SHARED_P(copy)) {
-            shared_root = ARY_SHARED_ROOT(copy);
-            FL_UNSET_SHARED(copy);
-        }
-        FL_SET_EMBED(copy);
-        ary_memcpy(copy, 0, RARRAY_LEN(orig), RARRAY_CONST_PTR_TRANSIENT(orig));
-        if (shared_root) {
-            rb_ary_decrement_share(shared_root);
-        }
-        ARY_SET_LEN(copy, RARRAY_LEN(orig));
+    /* orig has enough space to embed the contents of orig. */
+    if (RARRAY_LEN(orig) <= ary_embed_capa(copy)) {
+        RUBY_ASSERT(ARY_EMBED_P(copy));
+        ary_memcpy(copy, 0, RARRAY_LEN(orig), RARRAY_CONST_PTR(orig));
+        ARY_SET_EMBED_LEN(copy, RARRAY_LEN(orig));
     }
+    /* orig is embedded but copy does not have enough space to embed the
+     * contents of orig. */
+    else if (ARY_EMBED_P(orig)) {
+        long len = ARY_EMBED_LEN(orig);
+        VALUE *ptr = ary_heap_alloc_buffer(len);
+
+        FL_UNSET_EMBED(copy);
+        ARY_SET_PTR(copy, ptr);
+        ARY_SET_LEN(copy, len);
+        ARY_SET_CAPA(copy, len);
+
+        // No allocation and exception expected that could leave `copy` in a
+        // bad state from the edits above.
+        ary_memcpy(copy, 0, len, RARRAY_CONST_PTR(orig));
+    }
+    /* Otherwise, orig is on heap and copy does not have enough space to embed
+     * the contents of orig. */
     else {
         VALUE shared_root = ary_make_shared(orig);
-        if (ARY_OWNS_HEAP_P(copy)) {
-            ary_heap_free(copy);
-        }
-        else {
-            rb_ary_unshare_safe(copy);
-        }
         FL_UNSET_EMBED(copy);
         ARY_SET_PTR(copy, ARY_HEAP_PTR(orig));
         ARY_SET_LEN(copy, ARY_HEAP_LEN(orig));
         rb_ary_set_shared(copy, shared_root);
+
+        RUBY_ASSERT(RB_OBJ_SHAREABLE_P(copy) ? RB_OBJ_SHAREABLE_P(shared_root) : 1);
     }
     ary_verify(copy);
     return copy;
@@ -3856,12 +4847,14 @@ rb_ary_replace(VALUE copy, VALUE orig)
 
 /*
  *  call-seq:
- *     ary.clear    -> ary
+ *    clear -> self
+ *
+ *  Removes all elements from +self+; returns +self+:
  *
- *  Removes all elements from +self+.
+ *    a = [:foo, 'bar', 2]
+ *    a.clear # => []
  *
- *     a = [ "a", "b", "c", "d", "e" ]
- *     a.clear    #=> [ ]
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 VALUE
@@ -3869,11 +4862,9 @@ rb_ary_clear(VALUE ary)
 {
     rb_ary_modify_check(ary);
     if (ARY_SHARED_P(ary)) {
-	if (!ARY_EMBED_P(ary)) {
-	    rb_ary_unshare(ary);
-	    FL_SET_EMBED(ary);
-            ARY_SET_EMBED_LEN(ary, 0);
-	}
+        rb_ary_unshare(ary);
+        FL_SET_EMBED(ary);
+        ARY_SET_EMBED_LEN(ary, 0);
     }
     else {
         ARY_SET_LEN(ary, 0);
@@ -3887,32 +4878,182 @@ rb_ary_clear(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.fill(obj)                                 -> ary
- *     ary.fill(obj, start [, length])               -> ary
- *     ary.fill(obj, range)                          -> ary
- *     ary.fill {|index| block}                      -> ary
- *     ary.fill(start [, length]) {|index| block}    -> ary
- *     ary.fill(range) {|index| block}               -> ary
+ *    fill(object, start = nil, count = nil) -> self
+ *    fill(object, range) -> self
+ *    fill(start = nil, count = nil) {|element| ... } -> self
+ *    fill(range) {|element| ... } -> self
+ *
+ *  Replaces selected elements in +self+;
+ *  may add elements to +self+;
+ *  always returns +self+ (never a new array).
+ *
+ *  In brief:
+ *
+ *    # Non-negative start.
+ *    ['a', 'b', 'c', 'd'].fill('-', 1, 2)          # => ["a", "-", "-", "d"]
+ *    ['a', 'b', 'c', 'd'].fill(1, 2) {|e| e.to_s } # => ["a", "1", "2", "d"]
+ *
+ *    # Extends with specified values if necessary.
+ *    ['a', 'b', 'c', 'd'].fill('-', 3, 2)          # => ["a", "b", "c", "-", "-"]
+ *    ['a', 'b', 'c', 'd'].fill(3, 2) {|e| e.to_s } # => ["a", "b", "c", "3", "4"]
+ *
+ *    # Fills with nils if necessary.
+ *    ['a', 'b', 'c', 'd'].fill('-', 6, 2)          # => ["a", "b", "c", "d", nil, nil, "-", "-"]
+ *    ['a', 'b', 'c', 'd'].fill(6, 2) {|e| e.to_s } # => ["a", "b", "c", "d", nil, nil, "6", "7"]
+ *
+ *    # For negative start, counts backwards from the end.
+ *    ['a', 'b', 'c', 'd'].fill('-', -3, 3)          # => ["a", "-", "-", "-"]
+ *    ['a', 'b', 'c', 'd'].fill(-3, 3) {|e| e.to_s } # => ["a", "1", "2", "3"]
+ *
+ *    # Range.
+ *    ['a', 'b', 'c', 'd'].fill('-', 1..2)          # => ["a", "-", "-", "d"]
+ *    ['a', 'b', 'c', 'd'].fill(1..2) {|e| e.to_s } # => ["a", "1", "2", "d"]
+ *
+ *  When arguments +start+ and +count+ are given,
+ *  they select the elements of +self+ to be replaced;
+ *  each must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]
+ *  (or +nil+):
+ *
+ *  - +start+ specifies the zero-based offset of the first element to be replaced;
+ *    +nil+ means zero.
+ *  - +count+ is the number of consecutive elements to be replaced;
+ *    +nil+ means "all the rest."
+ *
+ *  With argument +object+ given,
+ *  that one object is used for all replacements:
+ *
+ *    o = Object.new           # => #<Object:0x0000014e7bff7600>
+ *    a = ['a', 'b', 'c', 'd'] # => ["a", "b", "c", "d"]
+ *    a.fill(o, 1, 2)
+ *    # => ["a", #<Object:0x0000014e7bff7600>, #<Object:0x0000014e7bff7600>, "d"]
+ *
+ *  With a block given, the block is called once for each element to be replaced;
+ *  the value passed to the block is the _index_ of the element to be replaced
+ *  (not the element itself);
+ *  the block's return value replaces the element:
+ *
+ *    a = ['a', 'b', 'c', 'd']               # => ["a", "b", "c", "d"]
+ *    a.fill(1, 2) {|element| element.to_s } # => ["a", "1", "2", "d"]
+ *
+ *  For arguments +start+ and +count+:
+ *
+ *  - If +start+ is non-negative,
+ *    replaces +count+ elements beginning at offset +start+:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', 0, 2) # => ["-", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1, 2) # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 2, 2) # => ["a", "b", "-", "-"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(0, 2) {|e| e.to_s } # => ["0", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1, 2) {|e| e.to_s } # => ["a", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2, 2) {|e| e.to_s } # => ["a", "b", "2", "3"]
+ *
+ *    Extends +self+ if necessary:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', 3, 2) # => ["a", "b", "c", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 4, 2) # => ["a", "b", "c", "d", "-", "-"]
  *
- *  The first three forms set the selected elements of +self+ (which
- *  may be the entire array) to +obj+.
+ *      ['a', 'b', 'c', 'd'].fill(3, 2) {|e| e.to_s } # => ["a", "b", "c", "3", "4"]
+ *      ['a', 'b', 'c', 'd'].fill(4, 2) {|e| e.to_s } # => ["a", "b", "c", "d", "4", "5"]
  *
- *  A +start+ of +nil+ is equivalent to zero.
+ *    Fills with +nil+ if necessary:
  *
- *  A +length+ of +nil+ is equivalent to the length of the array.
+ *      ['a', 'b', 'c', 'd'].fill('-', 5, 2) # => ["a", "b", "c", "d", nil, "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 6, 2) # => ["a", "b", "c", "d", nil, nil, "-", "-"]
  *
- *  The last three forms fill the array with the value of the given block,
- *  which is passed the absolute index of each element to be filled.
+ *      ['a', 'b', 'c', 'd'].fill(5, 2) {|e| e.to_s } # => ["a", "b", "c", "d", nil, "5", "6"]
+ *      ['a', 'b', 'c', 'd'].fill(6, 2) {|e| e.to_s } # => ["a", "b", "c", "d", nil, nil, "6", "7"]
  *
- *  Negative values of +start+ count from the end of the array, where +-1+ is
- *  the last element.
+ *    Does nothing if +count+ is non-positive:
  *
- *     a = [ "a", "b", "c", "d" ]
- *     a.fill("x")              #=> ["x", "x", "x", "x"]
- *     a.fill("z", 2, 2)        #=> ["x", "x", "z", "z"]
- *     a.fill("y", 0..1)        #=> ["y", "y", "z", "z"]
- *     a.fill {|i| i*i}         #=> [0, 1, 4, 9]
- *     a.fill(-2) {|i| i*i*i}   #=> [0, 1, 8, 27]
+ *      ['a', 'b', 'c', 'd'].fill('-', 2, 0)    # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 2, -100) # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 6, -100) # => ["a", "b", "c", "d"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(2, 0) {|e| fail 'Cannot happen' }    # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2, -100) {|e| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(6, -100) {|e| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *
+ *  - If +start+ is negative, counts backwards from the end of +self+:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', -4, 3) # => ["-", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -3, 3) # => ["a", "-", "-", "-"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(-4, 3) {|e| e.to_s } # => ["0", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-3, 3) {|e| e.to_s } # => ["a", "1", "2", "3"]
+ *
+ *    Extends +self+ if necessary:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', -2, 3) # => ["a", "b", "-", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -1, 3) # => ["a", "b", "c", "-", "-", "-"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(-2, 3) {|e| e.to_s } # => ["a", "b", "2", "3", "4"]
+ *      ['a', 'b', 'c', 'd'].fill(-1, 3) {|e| e.to_s } # => ["a", "b", "c", "3", "4", "5"]
+ *
+ *    Starts at the beginning of +self+ if +start+ is negative and out-of-range:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', -5, 2) # => ["-", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -6, 2) # => ["-", "-", "c", "d"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(-5, 2) {|e| e.to_s } # => ["0", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-6, 2) {|e| e.to_s } # => ["0", "1", "c", "d"]
+ *
+ *    Does nothing if +count+ is non-positive:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', -2, 0)  # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -2, -1) # => ["a", "b", "c", "d"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(-2, 0) {|e| fail 'Cannot happen' }  # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-2, -1) {|e| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *
+ *  When argument +range+ is given,
+ *  it must be a Range object whose members are numeric;
+ *  its +begin+ and +end+ values determine the elements of +self+
+ *  to be replaced:
+ *
+ *  - If both +begin+ and +end+ are positive, they specify the first and last elements
+ *    to be replaced:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..2)          # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1..2) {|e| e.to_s } # => ["a", "1", "2", "d"]
+ *
+ *    If +end+ is smaller than +begin+, replaces no elements:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', 2..1)          # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2..1) {|e| e.to_s } # => ["a", "b", "c", "d"]
+ *
+ *  - If either is negative (or both are negative), counts backwards from the end of +self+:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', -3..2)  # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..-2)  # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -3..-2) # => ["a", "-", "-", "d"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(-3..2) {|e| e.to_s }  # => ["a", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1..-2) {|e| e.to_s }  # => ["a", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-3..-2) {|e| e.to_s } # => ["a", "1", "2", "d"]
+ *
+ *  - If the +end+ value is excluded (see Range#exclude_end?), omits the last replacement:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', 1...2)  # => ["a", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1...-2) # => ["a", "-", "c", "d"]
+ *
+ *      ['a', 'b', 'c', 'd'].fill(1...2) {|e| e.to_s }  # => ["a", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1...-2) {|e| e.to_s } # => ["a", "1", "c", "d"]
+ *
+ *  - If the range is endless (see {Endless Ranges}[rdoc-ref:Range@Endless+Ranges]),
+ *    replaces elements to the end of +self+:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..)          # => ["a", "-", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill(1..) {|e| e.to_s } # => ["a", "1", "2", "3"]
+ *
+ *  - If the range is beginless (see {Beginless Ranges}[rdoc-ref:Range@Beginless+Ranges]),
+ *    replaces elements from the beginning of +self+:
+ *
+ *      ['a', 'b', 'c', 'd'].fill('-', ..2)          # => ["-", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(..2) {|e| e.to_s } # => ["0", "1", "2", "d"]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -3922,84 +5063,74 @@ rb_ary_fill(int argc, VALUE *argv, VALUE ary)
     long beg = 0, end = 0, len = 0;
 
     if (rb_block_given_p()) {
-	rb_scan_args(argc, argv, "02", &arg1, &arg2);
-	argc += 1;		/* hackish */
+        rb_scan_args(argc, argv, "02", &arg1, &arg2);
+        argc += 1;		/* hackish */
     }
     else {
-	rb_scan_args(argc, argv, "12", &item, &arg1, &arg2);
+        rb_scan_args(argc, argv, "12", &item, &arg1, &arg2);
     }
     switch (argc) {
       case 1:
-	beg = 0;
-	len = RARRAY_LEN(ary);
-	break;
+        beg = 0;
+        len = RARRAY_LEN(ary);
+        break;
       case 2:
-	if (rb_range_beg_len(arg1, &beg, &len, RARRAY_LEN(ary), 1)) {
-	    break;
-	}
-	/* fall through */
+        if (rb_range_beg_len(arg1, &beg, &len, RARRAY_LEN(ary), 1)) {
+            break;
+        }
+        /* fall through */
       case 3:
-	beg = NIL_P(arg1) ? 0 : NUM2LONG(arg1);
-	if (beg < 0) {
-	    beg = RARRAY_LEN(ary) + beg;
-	    if (beg < 0) beg = 0;
-	}
-	len = NIL_P(arg2) ? RARRAY_LEN(ary) - beg : NUM2LONG(arg2);
-	break;
+        beg = NIL_P(arg1) ? 0 : NUM2LONG(arg1);
+        if (beg < 0) {
+            beg = RARRAY_LEN(ary) + beg;
+            if (beg < 0) beg = 0;
+        }
+        len = NIL_P(arg2) ? RARRAY_LEN(ary) - beg : NUM2LONG(arg2);
+        break;
     }
     rb_ary_modify(ary);
     if (len < 0) {
         return ary;
     }
     if (beg >= ARY_MAX_SIZE || len > ARY_MAX_SIZE - beg) {
-	rb_raise(rb_eArgError, "argument too big");
+        rb_raise(rb_eArgError, "argument too big");
     }
     end = beg + len;
     if (RARRAY_LEN(ary) < end) {
-	if (end >= ARY_CAPA(ary)) {
-	    ary_resize_capa(ary, end);
-	}
-	ary_mem_clear(ary, RARRAY_LEN(ary), end - RARRAY_LEN(ary));
-	ARY_SET_LEN(ary, end);
+        if (end >= ARY_CAPA(ary)) {
+            ary_resize_capa(ary, end);
+        }
+        ary_mem_clear(ary, RARRAY_LEN(ary), end - RARRAY_LEN(ary));
+        ARY_SET_LEN(ary, end);
     }
 
-    if (item == Qundef) {
-	VALUE v;
-	long i;
+    if (UNDEF_P(item)) {
+        VALUE v;
+        long i;
 
-	for (i=beg; i<end; i++) {
-	    v = rb_yield(LONG2NUM(i));
-	    if (i>=RARRAY_LEN(ary)) break;
-	    ARY_SET(ary, i, v);
-	}
+        for (i=beg; i<end; i++) {
+            v = rb_yield(LONG2NUM(i));
+            if (i>=RARRAY_LEN(ary)) break;
+            ARY_SET(ary, i, v);
+        }
     }
     else {
-	ary_memfill(ary, beg, len, item);
+        ary_memfill(ary, beg, len, item);
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary + other_ary   -> new_ary
- *
- *  Concatenation --- Returns a new array built by concatenating the
- *  two arrays together to produce a third array.
+ *    self + other_array -> new_array
  *
- *     [ 1, 2, 3 ] + [ 4, 5 ]    #=> [ 1, 2, 3, 4, 5 ]
- *     a = [ "a", "b", "c" ]
- *     c = a + [ "d", "e", "f" ]
- *     c                         #=> [ "a", "b", "c", "d", "e", "f" ]
- *     a                         #=> [ "a", "b", "c" ]
+ *  Returns a new array containing all elements of +self+
+ *  followed by all elements of +other_array+:
  *
- *  Note that
- *     x += y
- *  is the same as
- *     x = x + y
- *  This means that it produces a new array. As a consequence,
- *  repeated use of <code>+=</code> on arrays can be quite inefficient.
+ *    a = [0, 1] + [2, 3]
+ *    a # => [0, 1, 2, 3]
  *
- *  See also Array#concat.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 VALUE
@@ -4014,8 +5145,8 @@ rb_ary_plus(VALUE x, VALUE y)
     len = xlen + ylen;
     z = rb_ary_new2(len);
 
-    ary_memcpy(z, 0, xlen, RARRAY_CONST_PTR_TRANSIENT(x));
-    ary_memcpy(z, xlen, ylen, RARRAY_CONST_PTR_TRANSIENT(y));
+    ary_memcpy(z, 0, xlen, RARRAY_CONST_PTR(x));
+    ary_memcpy(z, xlen, ylen, RARRAY_CONST_PTR(y));
     ARY_SET_LEN(z, len);
     return z;
 }
@@ -4025,29 +5156,23 @@ ary_append(VALUE x, VALUE y)
 {
     long n = RARRAY_LEN(y);
     if (n > 0) {
-        rb_ary_splice(x, RARRAY_LEN(x), 0, RARRAY_CONST_PTR_TRANSIENT(y), n);
+        rb_ary_splice(x, RARRAY_LEN(x), 0, RARRAY_CONST_PTR(y), n);
     }
+    RB_GC_GUARD(y);
     return x;
 }
 
 /*
  *  call-seq:
- *     ary.concat(other_ary1, other_ary2, ...)   -> ary
- *
- *  Appends the elements of <code>other_ary</code>s to +self+.
+ *    concat(*other_arrays) -> self
  *
- *     [ "a", "b" ].concat( ["c", "d"])   #=> [ "a", "b", "c", "d" ]
- *     [ "a" ].concat( ["b"], ["c", "d"]) #=> [ "a", "b", "c", "d" ]
- *     [ "a" ].concat #=> [ "a" ]
+ *  Adds to +self+ all elements from each array in +other_arrays+; returns +self+:
  *
- *     a = [ 1, 2, 3 ]
- *     a.concat( [ 4, 5 ])
- *     a                                 #=> [ 1, 2, 3, 4, 5 ]
+ *    a = [0, 1]
+ *    a.concat(['two', 'three'], [:four, :five], a)
+ *    # => [0, 1, "two", "three", :four, :five, 0, 1]
  *
- *     a = [ 1, 2 ]
- *     a.concat(a, a)                    #=> [1, 2, 1, 2, 1, 2]
- *
- *  See also Array#+.
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -4056,15 +5181,15 @@ rb_ary_concat_multi(int argc, VALUE *argv, VALUE ary)
     rb_ary_modify_check(ary);
 
     if (argc == 1) {
-	rb_ary_concat(ary, argv[0]);
+        rb_ary_concat(ary, argv[0]);
     }
     else if (argc > 1) {
-	int i;
-	VALUE args = rb_ary_tmp_new(argc);
-	for (i = 0; i < argc; i++) {
-	    rb_ary_concat(args, argv[i]);
-	}
-	ary_append(ary, args);
+        int i;
+        VALUE args = rb_ary_hidden_new(argc);
+        for (i = 0; i < argc; i++) {
+            rb_ary_concat(args, argv[i]);
+        }
+        ary_append(ary, args);
     }
 
     ary_verify(ary);
@@ -4079,18 +5204,19 @@ rb_ary_concat(VALUE x, VALUE y)
 
 /*
  *  call-seq:
- *     ary * int     -> new_ary
- *     ary * str     -> new_string
+ *    self * n -> new_array
+ *    self * string_separator -> new_string
  *
- *  Repetition --- With a String argument, equivalent to
- *  <code>ary.join(str)</code>.
+ *  When non-negative integer argument +n+ is given,
+ *  returns a new array built by concatenating +n+ copies of +self+:
  *
- *  Otherwise, returns a new array built by concatenating the +int+ copies of
- *  +self+.
+ *    a = ['x', 'y']
+ *    a * 3 # => ["x", "y", "x", "y", "x", "y"]
  *
+ *  When string argument +string_separator+ is given,
+ *  equivalent to <tt>self.join(string_separator)</tt>:
  *
- *     [ 1, 2, 3 ] * 3    #=> [ 1, 2, 3, 1, 2, 3, 1, 2, 3 ]
- *     [ 1, 2, 3 ] * ","  #=> "1,2,3"
+ *    [0, [0, 1], {foo: 0}] * ', ' # => "0, 0, 1, {foo: 0}"
  *
  */
 
@@ -4103,61 +5229,55 @@ rb_ary_times(VALUE ary, VALUE times)
 
     tmp = rb_check_string_type(times);
     if (!NIL_P(tmp)) {
-	return rb_ary_join(ary, tmp);
+        return rb_ary_join(ary, tmp);
     }
 
     len = NUM2LONG(times);
     if (len == 0) {
-	ary2 = ary_new(rb_obj_class(ary), 0);
-	goto out;
+        ary2 = ary_new(rb_cArray, 0);
+        goto out;
     }
     if (len < 0) {
-	rb_raise(rb_eArgError, "negative argument");
+        rb_raise(rb_eArgError, "negative argument");
     }
     if (ARY_MAX_SIZE/len < RARRAY_LEN(ary)) {
-	rb_raise(rb_eArgError, "argument too big");
+        rb_raise(rb_eArgError, "argument too big");
     }
     len *= RARRAY_LEN(ary);
 
-    ary2 = ary_new(rb_obj_class(ary), len);
+    ary2 = ary_new(rb_cArray, len);
     ARY_SET_LEN(ary2, len);
 
-    ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+    ptr = RARRAY_CONST_PTR(ary);
     t = RARRAY_LEN(ary);
     if (0 < t) {
-	ary_memcpy(ary2, 0, t, ptr);
-	while (t <= len/2) {
-            ary_memcpy(ary2, t, t, RARRAY_CONST_PTR_TRANSIENT(ary2));
+        ary_memcpy(ary2, 0, t, ptr);
+        while (t <= len/2) {
+            ary_memcpy(ary2, t, t, RARRAY_CONST_PTR(ary2));
             t *= 2;
         }
         if (t < len) {
-            ary_memcpy(ary2, t, len-t, RARRAY_CONST_PTR_TRANSIENT(ary2));
+            ary_memcpy(ary2, t, len-t, RARRAY_CONST_PTR(ary2));
         }
     }
   out:
-    OBJ_INFECT(ary2, ary);
-
     return ary2;
 }
 
 /*
  *  call-seq:
- *     ary.assoc(obj)   -> element_ary  or  nil
+ *    assoc(object) -> found_array or nil
  *
- *  Searches through an array whose elements are also arrays comparing +obj+
- *  with the first element of each contained array using <code>obj.==</code>.
+ *  Returns the first element +ele+ in +self+ such that +ele+ is an array
+ *  and <tt>ele[0] == object</tt>:
  *
- *  Returns the first contained array that matches (that is, the first
- *  associated array), or +nil+ if no match is found.
+ *    a = [{foo: 0}, [2, 4], [4, 5, 6], [4, 5]]
+ *    a.assoc(4) # => [4, 5, 6]
  *
- *  See also Array#rassoc
+ *  Returns +nil+ if no such element is found.
  *
- *     s1 = [ "colors", "red", "blue", "green" ]
- *     s2 = [ "letters", "a", "b", "c" ]
- *     s3 = "foo"
- *     a  = [ s1, s2, s3 ]
- *     a.assoc("letters")  #=> [ "letters", "a", "b", "c" ]
- *     a.assoc("foo")      #=> nil
+ *  Related: Array#rassoc;
+ *  see also {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -4167,30 +5287,29 @@ rb_ary_assoc(VALUE ary, VALUE key)
     VALUE v;
 
     for (i = 0; i < RARRAY_LEN(ary); ++i) {
-	v = rb_check_array_type(RARRAY_AREF(ary, i));
-	if (!NIL_P(v) && RARRAY_LEN(v) > 0 &&
-	    rb_equal(RARRAY_AREF(v, 0), key))
-	    return v;
+        v = rb_check_array_type(RARRAY_AREF(ary, i));
+        if (!NIL_P(v) && RARRAY_LEN(v) > 0 &&
+            rb_equal(RARRAY_AREF(v, 0), key))
+            return v;
     }
     return Qnil;
 }
 
 /*
  *  call-seq:
- *     ary.rassoc(obj) -> element_ary or nil
- *
- *  Searches through the array whose elements are also arrays.
+ *    rassoc(object) -> found_array or nil
  *
- *  Compares +obj+ with the second element of each contained array using
- *  <code>obj.==</code>.
+ *  Returns the first element +ele+ in +self+ such that +ele+ is an array
+ *  and <tt>ele[1] == object</tt>:
  *
- *  Returns the first contained array that matches +obj+.
+ *    a = [{foo: 0}, [2, 4], [4, 5, 6], [4, 5]]
+ *    a.rassoc(4) # => [2, 4]
+ *    a.rassoc(5) # => [4, 5, 6]
  *
- *  See also Array#assoc.
+ *  Returns +nil+ if no such element is found.
  *
- *     a = [ [ 1, "one"], [2, "two"], [3, "three"], ["ii", "two"] ]
- *     a.rassoc("two")    #=> [2, "two"]
- *     a.rassoc("four")   #=> nil
+ *  Related: Array#assoc;
+ *  see also {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -4200,11 +5319,11 @@ rb_ary_rassoc(VALUE ary, VALUE value)
     VALUE v;
 
     for (i = 0; i < RARRAY_LEN(ary); ++i) {
-	v = RARRAY_AREF(ary, i);
-	if (RB_TYPE_P(v, T_ARRAY) &&
-	    RARRAY_LEN(v) > 1 &&
-	    rb_equal(RARRAY_AREF(v, 1), value))
-	    return v;
+        v = rb_check_array_type(RARRAY_AREF(ary, i));
+        if (RB_TYPE_P(v, T_ARRAY) &&
+            RARRAY_LEN(v) > 1 &&
+            rb_equal(RARRAY_AREF(v, 1), value))
+            return v;
     }
     return Qnil;
 }
@@ -4223,38 +5342,48 @@ recursive_equal(VALUE ary1, VALUE ary2, int recur)
     len1 = RARRAY_LEN(ary1);
 
     for (i = 0; i < len1; i++) {
-	if (*p1 != *p2) {
-	    if (rb_equal(*p1, *p2)) {
-		len1 = RARRAY_LEN(ary1);
-		if (len1 != RARRAY_LEN(ary2))
-		    return Qfalse;
-		if (len1 < i)
-		    return Qtrue;
+        if (*p1 != *p2) {
+            if (rb_equal(*p1, *p2)) {
+                len1 = RARRAY_LEN(ary1);
+                if (len1 != RARRAY_LEN(ary2))
+                    return Qfalse;
+                if (len1 < i)
+                    return Qtrue;
                 p1 = RARRAY_CONST_PTR(ary1) + i;
                 p2 = RARRAY_CONST_PTR(ary2) + i;
-	    }
-	    else {
-		return Qfalse;
-	    }
-	}
-	p1++;
-	p2++;
+            }
+            else {
+                return Qfalse;
+            }
+        }
+        p1++;
+        p2++;
     }
     return Qtrue;
 }
 
 /*
  *  call-seq:
- *     ary == other_ary   ->   bool
+ *    self == other_array -> true or false
+ *
+ *  Returns whether both:
+ *
+ *  - +self+ and +other_array+ are the same size.
+ *  - Their corresponding elements are the same;
+ *    that is, for each index +i+ in <tt>(0...self.size)</tt>,
+ *    <tt>self[i] == other_array[i]</tt>.
+ *
+ *  Examples:
  *
- *  Equality --- Two arrays are equal if they contain the same number of
- *  elements and if each element is equal to (according to Object#==) the
- *  corresponding element in +other_ary+.
+ *    [:foo, 'bar', 2] == [:foo, 'bar', 2]   # => true
+ *    [:foo, 'bar', 2] == [:foo, 'bar', 2.0] # => true
+ *    [:foo, 'bar', 2] == [:foo, 'bar']      # => false # Different sizes.
+ *    [:foo, 'bar', 2] == [:foo, 'bar', 3]   # => false # Different elements.
  *
- *     [ "a", "c" ]    == [ "a", "c", 7 ]     #=> false
- *     [ "a", "c", 7 ] == [ "a", "c", 7 ]     #=> true
- *     [ "a", "c", 7 ] == [ "a", "d", "f" ]   #=> false
+ *  This method is different from method Array#eql?,
+ *  which compares elements using <tt>Object#eql?</tt>.
  *
+ *  Related: see {Methods for Comparing}[rdoc-ref:Array@Methods+for+Comparing].
  */
 
 static VALUE
@@ -4262,13 +5391,13 @@ rb_ary_equal(VALUE ary1, VALUE ary2)
 {
     if (ary1 == ary2) return Qtrue;
     if (!RB_TYPE_P(ary2, T_ARRAY)) {
-	if (!rb_respond_to(ary2, idTo_ary)) {
-	    return Qfalse;
-	}
-	return rb_equal(ary2, ary1);
+        if (!rb_respond_to(ary2, idTo_ary)) {
+            return Qfalse;
+        }
+        return rb_equal(ary2, ary1);
     }
     if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
-    if (RARRAY_CONST_PTR_TRANSIENT(ary1) == RARRAY_CONST_PTR_TRANSIENT(ary2)) return Qtrue;
+    if (RARRAY_CONST_PTR(ary1) == RARRAY_CONST_PTR(ary2)) return Qtrue;
     return rb_exec_recursive_paired(recursive_equal, ary1, ary2, ary2);
 }
 
@@ -4279,18 +5408,29 @@ recursive_eql(VALUE ary1, VALUE ary2, int recur)
 
     if (recur) return Qtrue; /* Subtle! */
     for (i=0; i<RARRAY_LEN(ary1); i++) {
-	if (!rb_eql(rb_ary_elt(ary1, i), rb_ary_elt(ary2, i)))
-	    return Qfalse;
+        if (!rb_eql(rb_ary_elt(ary1, i), rb_ary_elt(ary2, i)))
+            return Qfalse;
     }
     return Qtrue;
 }
 
 /*
  *  call-seq:
- *     ary.eql?(other)  -> true or false
+ *    eql?(other_array) -> true or false
+ *
+ *  Returns +true+ if +self+ and +other_array+ are the same size,
+ *  and if, for each index +i+ in +self+, <tt>self[i].eql?(other_array[i])</tt>:
+ *
+ *    a0 = [:foo, 'bar', 2]
+ *    a1 = [:foo, 'bar', 2]
+ *    a1.eql?(a0) # => true
  *
- *  Returns +true+ if +self+ and +other+ are the same object,
- *  or are both arrays with the same content (according to Object#eql?).
+ *  Otherwise, returns +false+.
+ *
+ *  This method is different from method Array#==,
+ *  which compares using method <tt>Object#==</tt>.
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -4299,49 +5439,71 @@ rb_ary_eql(VALUE ary1, VALUE ary2)
     if (ary1 == ary2) return Qtrue;
     if (!RB_TYPE_P(ary2, T_ARRAY)) return Qfalse;
     if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
-    if (RARRAY_CONST_PTR_TRANSIENT(ary1) == RARRAY_CONST_PTR_TRANSIENT(ary2)) return Qtrue;
+    if (RARRAY_CONST_PTR(ary1) == RARRAY_CONST_PTR(ary2)) return Qtrue;
     return rb_exec_recursive_paired(recursive_eql, ary1, ary2, ary2);
 }
 
+static VALUE
+ary_hash_values(long len, const VALUE *elements, const VALUE ary)
+{
+    long i;
+    st_index_t h;
+    VALUE n;
+
+    h = rb_hash_start(len);
+    h = rb_hash_uint(h, (st_index_t)rb_ary_hash_values);
+    for (i=0; i<len; i++) {
+        n = rb_hash(elements[i]);
+        h = rb_hash_uint(h, NUM2LONG(n));
+        if (ary) {
+            len = RARRAY_LEN(ary);
+            elements = RARRAY_CONST_PTR(ary);
+        }
+    }
+    h = rb_hash_end(h);
+    return ST2FIX(h);
+}
+
+VALUE
+rb_ary_hash_values(long len, const VALUE *elements)
+{
+    return ary_hash_values(len, elements, 0);
+}
+
 /*
  *  call-seq:
- *     ary.hash   -> integer
+ *    hash -> integer
+ *
+ *  Returns the integer hash value for +self+.
  *
- *  Compute a hash-code for this array.
+ *  Two arrays with the same content will have the same hash value
+ *  (and will compare using eql?):
  *
- *  Two arrays with the same content will have the same hash code (and will
- *  compare using #eql?).
+ *    ['a', 'b'].hash == ['a', 'b'].hash # => true
+ *    ['a', 'b'].hash == ['a', 'c'].hash # => false
+ *    ['a', 'b'].hash == ['a'].hash      # => false
  *
- *  See also Object#hash.
  */
 
 static VALUE
 rb_ary_hash(VALUE ary)
 {
-    long i;
-    st_index_t h;
-    VALUE n;
-
-    h = rb_hash_start(RARRAY_LEN(ary));
-    h = rb_hash_uint(h, (st_index_t)rb_ary_hash);
-    for (i=0; i<RARRAY_LEN(ary); i++) {
-	n = rb_hash(RARRAY_AREF(ary, i));
-	h = rb_hash_uint(h, NUM2LONG(n));
-    }
-    h = rb_hash_end(h);
-    return ST2FIX(h);
+    RBIMPL_ASSERT_OR_ASSUME(ary);
+    return ary_hash_values(RARRAY_LEN(ary), RARRAY_CONST_PTR(ary), ary);
 }
 
 /*
  *  call-seq:
- *     ary.include?(object)   -> true or false
+ *    include?(object) -> true or false
+ *
+ *  Returns whether for some element +element+ in +self+,
+ *  <tt>object == element</tt>:
  *
- *  Returns +true+ if the given +object+ is present in +self+ (that is, if any
- *  element <code>==</code> +object+), otherwise returns +false+.
+ *    [0, 1, 2].include?(2)   # => true
+ *    [0, 1, 2].include?(2.0) # => true
+ *    [0, 1, 2].include?(2.1) # => false
  *
- *     a = [ "a", "b", "c" ]
- *     a.include?("b")   #=> true
- *     a.include?("z")   #=> false
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 VALUE
@@ -4351,10 +5513,10 @@ rb_ary_includes(VALUE ary, VALUE item)
     VALUE e;
 
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	e = RARRAY_AREF(ary, i);
-	if (rb_equal(e, item)) {
-	    return Qtrue;
-	}
+        e = RARRAY_AREF(ary, i);
+        if (rb_equal(e, item)) {
+            return Qtrue;
+        }
     }
     return Qfalse;
 }
@@ -4366,10 +5528,10 @@ rb_ary_includes_by_eql(VALUE ary, VALUE item)
     VALUE e;
 
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	e = RARRAY_AREF(ary, i);
-	if (rb_eql(item, e)) {
-	    return Qtrue;
-	}
+        e = RARRAY_AREF(ary, i);
+        if (rb_eql(item, e)) {
+            return Qtrue;
+        }
     }
     return Qfalse;
 }
@@ -4382,46 +5544,54 @@ recursive_cmp(VALUE ary1, VALUE ary2, int recur)
     if (recur) return Qundef;	/* Subtle! */
     len = RARRAY_LEN(ary1);
     if (len > RARRAY_LEN(ary2)) {
-	len = RARRAY_LEN(ary2);
+        len = RARRAY_LEN(ary2);
     }
     for (i=0; i<len; i++) {
-	VALUE e1 = rb_ary_elt(ary1, i), e2 = rb_ary_elt(ary2, i);
-	VALUE v = rb_funcallv(e1, id_cmp, 1, &e2);
-	if (v != INT2FIX(0)) {
-	    return v;
-	}
+        VALUE e1 = rb_ary_elt(ary1, i), e2 = rb_ary_elt(ary2, i);
+        VALUE v = rb_funcallv(e1, id_cmp, 1, &e2);
+        if (v != INT2FIX(0)) {
+            return v;
+        }
     }
     return Qundef;
 }
 
 /*
  *  call-seq:
- *     ary <=> other_ary   ->  -1, 0, +1 or nil
+ *    self <=> other_array -> -1, 0, or 1
+ *
+ *  Returns -1, 0, or 1 as +self+ is determined
+ *  to be less than, equal to, or greater than +other_array+.
+ *
+ *  Iterates over each index +i+ in <tt>(0...self.size)</tt>:
+ *
+ *  - Computes <tt>result[i]</tt> as <tt>self[i] <=> other_array[i]</tt>.
+ *  - Immediately returns 1 if <tt>result[i]</tt> is 1:
+ *
+ *      [0, 1, 2] <=> [0, 0, 2] # => 1
+ *
+ *  - Immediately returns -1 if <tt>result[i]</tt> is -1:
  *
- *  Comparison --- Returns an integer (+-1+, +0+, or <code>+1</code>) if this
- *  array is less than, equal to, or greater than +other_ary+.
+ *      [0, 1, 2] <=> [0, 2, 2] # => -1
  *
- *  Each object in each array is compared (using the <=> operator).
+ *  - Continues if <tt>result[i]</tt> is 0.
  *
- *  Arrays are compared in an "element-wise" manner; the first element of +ary+
- *  is compared with the first one of +other_ary+ using the <=> operator, then
- *  each of the second elements, etc...
- *  As soon as the result of any such comparison is non zero (i.e. the two
- *  corresponding elements are not equal), that result is returned for the
- *  whole array comparison.
+ *  When every +result+ is 0,
+ *  returns <tt>self.size <=> other_array.size</tt>
+ *  (see Integer#<=>):
  *
- *  If all the elements are equal, then the result is based on a comparison of
- *  the array lengths. Thus, two arrays are "equal" according to Array#<=> if,
- *  and only if, they have the same length and the value of each element is
- *  equal to the value of the corresponding element in the other array.
+ *    [0, 1, 2] <=> [0, 1]        # => 1
+ *    [0, 1, 2] <=> [0, 1, 2]     # => 0
+ *    [0, 1, 2] <=> [0, 1, 2, 3]  # => -1
  *
- *  +nil+ is returned if the +other_ary+ is not an array or if the comparison
- *  of two elements returned +nil+.
+ *  Note that when +other_array+ is larger than +self+,
+ *  its trailing elements do not affect the result:
  *
- *     [ "a", "a", "c" ]    <=> [ "a", "b", "c" ]   #=> -1
- *     [ 1, 2, 3, 4, 5, 6 ] <=> [ 1, 2 ]            #=> +1
- *     [ 1, 2 ]             <=> [ 1, :two ]         #=> nil
+ *    [0, 1, 2] <=> [0, 1, 2, -3] # => -1
+ *    [0, 1, 2] <=> [0, 1, 2, 0]  # => -1
+ *    [0, 1, 2] <=> [0, 1, 2, 3]  # => -1
  *
+ *  Related: see {Methods for Comparing}[rdoc-ref:Array@Methods+for+Comparing].
  */
 
 VALUE
@@ -4434,7 +5604,7 @@ rb_ary_cmp(VALUE ary1, VALUE ary2)
     if (NIL_P(ary2)) return Qnil;
     if (ary1 == ary2) return INT2FIX(0);
     v = rb_exec_recursive_paired(recursive_cmp, ary1, ary2, ary2);
-    if (v != Qundef) return v;
+    if (!UNDEF_P(v)) return v;
     len = RARRAY_LEN(ary1) - RARRAY_LEN(ary2);
     if (len == 0) return INT2FIX(0);
     if (len > 0) return INT2FIX(1);
@@ -4447,8 +5617,8 @@ ary_add_hash(VALUE hash, VALUE ary)
     long i;
 
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	VALUE elt = RARRAY_AREF(ary, i);
-	rb_hash_add_new_element(hash, elt, elt);
+        VALUE elt = RARRAY_AREF(ary, i);
+        rb_hash_add_new_element(hash, elt, elt);
     }
     return hash;
 }
@@ -4476,8 +5646,8 @@ ary_add_hash_by(VALUE hash, VALUE ary)
     long i;
 
     for (i = 0; i < RARRAY_LEN(ary); ++i) {
-	VALUE v = rb_ary_elt(ary, i), k = rb_yield(v);
-	rb_hash_add_new_element(hash, k, v);
+        VALUE v = rb_ary_elt(ary, i), k = rb_yield(v);
+        rb_hash_add_new_element(hash, k, v);
     }
     return hash;
 }
@@ -4489,41 +5659,25 @@ ary_make_hash_by(VALUE ary)
     return ary_add_hash_by(hash, ary);
 }
 
-static inline void
-ary_recycle_hash(VALUE hash)
-{
-    assert(RBASIC_CLASS(hash) == 0);
-    if (RHASH_ST_TABLE_P(hash)) {
-        st_table *tbl = RHASH_ST_TABLE(hash);
-	st_free_table(tbl);
-        RHASH_ST_CLEAR(hash);
-    }
-}
-
 /*
  *  call-seq:
- *     ary - other_ary    -> new_ary
+ *    self - other_array -> new_array
  *
- *  Array Difference
+ *  Returns a new array containing only those elements of +self+
+ *  that are not found in +other_array+;
+ *  the order from +self+ is preserved:
  *
- *  Returns a new array that is a copy of the original array, removing all
- *  occurrences of any item that also appear in +other_ary+. The order is
- *  preserved from the original array.
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [1]             # => [0, 2, 3]
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [3, 2, 0, :foo] # => [1, 1, 1, 1, 1, 1]
+ *    [0, 1, 2] - [:foo]                            # => [0, 1, 2]
  *
- *  It compares elements using their #hash and #eql? methods for efficiency.
+ *  Element are compared using method <tt>#eql?</tt>
+ *  (as defined in each element of +self+).
  *
- *     [ 1, 1, 2, 2, 3, 3, 4, 5 ] - [ 1, 2, 4 ]  #=>  [ 3, 3, 5 ]
- *
- *  Note that while 1 and 2 were only present once in the array argument, and
- *  were present twice in the receiver array, all occurrences of each Integer are
- *  removed in the returned array.
- *
- *  If you need set-like behavior, see the library class Set.
- *
- *  See also Array#difference.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
-static VALUE
+VALUE
 rb_ary_diff(VALUE ary1, VALUE ary2)
 {
     VALUE ary3;
@@ -4531,53 +5685,44 @@ rb_ary_diff(VALUE ary1, VALUE ary2)
     long i;
 
     ary2 = to_ary(ary2);
+    if (RARRAY_LEN(ary2) == 0) { return ary_make_shared_copy(ary1); }
     ary3 = rb_ary_new();
 
     if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN || RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
-	for (i=0; i<RARRAY_LEN(ary1); i++) {
-	    VALUE elt = rb_ary_elt(ary1, i);
-	    if (rb_ary_includes_by_eql(ary2, elt)) continue;
-	    rb_ary_push(ary3, elt);
-	}
-	return ary3;
+        for (i=0; i<RARRAY_LEN(ary1); i++) {
+            VALUE elt = rb_ary_elt(ary1, i);
+            if (rb_ary_includes_by_eql(ary2, elt)) continue;
+            rb_ary_push(ary3, elt);
+        }
+        return ary3;
     }
 
     hash = ary_make_hash(ary2);
     for (i=0; i<RARRAY_LEN(ary1); i++) {
         if (rb_hash_stlike_lookup(hash, RARRAY_AREF(ary1, i), NULL)) continue;
-	rb_ary_push(ary3, rb_ary_elt(ary1, i));
+        rb_ary_push(ary3, rb_ary_elt(ary1, i));
     }
-    ary_recycle_hash(hash);
+
     return ary3;
 }
 
 /*
  *  call-seq:
- *     ary.difference(other_ary1, other_ary2, ...)   -> new_ary
- *
- *  Array Difference
- *
- *  Returns a new array that is a copy of the original array, removing all
- *  occurrences of any item that also appear in +other_ary+. The order is
- *  preserved from the original array.
- *
- *  It compares elements using their #hash and #eql? methods for efficiency.
- *
- *     [ 1, 1, 2, 2, 3, 3, 4, 5 ].difference([ 1, 2, 4 ])     #=> [ 3, 3, 5 ]
- *
- *  Note that while 1 and 2 were only present once in the array argument, and
- *  were present twice in the receiver array, all occurrences of each Integer are
- *  removed in the returned array.
+ *    difference(*other_arrays = []) -> new_array
  *
- *  Multiple array arguments can be supplied and all occurrences of any element
- *  in those supplied arrays that match the receiver will be removed from the
- *  returned array.
+ *  Returns a new array containing only those elements from +self+
+ *  that are not found in any of the given +other_arrays+;
+ *  items are compared using <tt>eql?</tt>;  order from +self+ is preserved:
  *
- *     [ 1, 'c', :s, 'yep' ].difference([ 1 ], [ 'a', 'c' ])  #=> [ :s, "yep" ]
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1].difference([1]) # => [0, 2, 3]
+ *    [0, 1, 2, 3].difference([3, 0], [1, 3])     # => [2]
+ *    [0, 1, 2].difference([4])                   # => [0, 1, 2]
+ *    [0, 1, 2].difference                        # => [0, 1, 2]
  *
- *  If you need set-like behavior, see the library class Set.
+ *  Returns a copy of +self+ if no arguments are given.
  *
- *  See also Array#-.
+ *  Related: Array#-;
+ *  see also {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -4601,7 +5746,7 @@ rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
         VALUE elt = rb_ary_elt(ary, i);
         for (j = 0; j < argc; j++) {
             if (is_hash[j]) {
-                if (rb_hash_stlike_lookup(argv[j], RARRAY_AREF(ary, i), NULL))
+                if (rb_hash_stlike_lookup(argv[j], elt, NULL))
                     break;
             }
             else {
@@ -4619,17 +5764,25 @@ rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary & other_ary      -> new_ary
+ *    self & other_array -> new_array
  *
- *  Set Intersection --- Returns a new array containing unique elements common to the
- *  two arrays. The order is preserved from the original array.
+ *  Returns a new array containing the _intersection_ of +self+ and +other_array+;
+ *  that is, containing those elements found in both +self+ and +other_array+:
  *
- *  It compares elements using their #hash and #eql? methods for efficiency.
+ *    [0, 1, 2, 3] & [1, 2] # => [1, 2]
  *
- *     [ 1, 1, 3, 5 ] & [ 3, 2, 1 ]                 #=> [ 1, 3 ]
- *     [ 'a', 'b', 'b', 'z' ] & [ 'a', 'b', 'c' ]   #=> [ 'a', 'b' ]
+ *  Omits duplicates:
  *
- *  See also Array#uniq.
+ *    [0, 1, 1, 0] & [0, 1] # => [0, 1]
+ *
+ *  Preserves order from +self+:
+ *
+ *    [0, 1, 2] & [3, 2, 1, 0] # => [0, 1, 2]
+ *
+ *  Identifies common elements using method <tt>#eql?</tt>
+ *  (as defined in each element of +self+).
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 
@@ -4645,29 +5798,62 @@ rb_ary_and(VALUE ary1, VALUE ary2)
     if (RARRAY_LEN(ary1) == 0 || RARRAY_LEN(ary2) == 0) return ary3;
 
     if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN && RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
-	for (i=0; i<RARRAY_LEN(ary1); i++) {
-	    v = RARRAY_AREF(ary1, i);
-	    if (!rb_ary_includes_by_eql(ary2, v)) continue;
-	    if (rb_ary_includes_by_eql(ary3, v)) continue;
-	    rb_ary_push(ary3, v);
-	}
-	return ary3;
+        for (i=0; i<RARRAY_LEN(ary1); i++) {
+            v = RARRAY_AREF(ary1, i);
+            if (!rb_ary_includes_by_eql(ary2, v)) continue;
+            if (rb_ary_includes_by_eql(ary3, v)) continue;
+            rb_ary_push(ary3, v);
+        }
+        return ary3;
     }
 
     hash = ary_make_hash(ary2);
 
     for (i=0; i<RARRAY_LEN(ary1); i++) {
-	v = RARRAY_AREF(ary1, i);
-	vv = (st_data_t)v;
+        v = RARRAY_AREF(ary1, i);
+        vv = (st_data_t)v;
         if (rb_hash_stlike_delete(hash, &vv, 0)) {
-	    rb_ary_push(ary3, v);
-	}
+            rb_ary_push(ary3, v);
+        }
     }
-    ary_recycle_hash(hash);
 
     return ary3;
 }
 
+/*
+ *  call-seq:
+ *    intersection(*other_arrays) -> new_array
+ *
+ *  Returns a new array containing each element in +self+ that is +#eql?+
+ *  to at least one element in each of the given +other_arrays+;
+ *  duplicates are omitted:
+ *
+ *    [0, 0, 1, 1, 2, 3].intersection([0, 1, 2], [0, 1, 3]) # => [0, 1]
+ *
+ *  Each element must correctly implement method <tt>#hash</tt>.
+ *
+ *  Order from +self+ is preserved:
+ *
+ *    [0, 1, 2].intersection([2, 1, 0]) # => [0, 1, 2]
+ *
+ *  Returns a copy of +self+ if no arguments are given.
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
+ */
+
+static VALUE
+rb_ary_intersection_multi(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE result = rb_ary_dup(ary);
+    int i;
+
+    for (i = 0; i < argc; i++) {
+        result = rb_ary_and(result, argv[i]);
+    }
+
+    return result;
+}
+
 static int
 ary_hash_orset(st_data_t *key, st_data_t *value, st_data_t arg, int existing)
 {
@@ -4701,54 +5887,59 @@ rb_ary_union_hash(VALUE hash, VALUE ary2)
 
 /*
  *  call-seq:
- *     ary | other_ary     -> new_ary
+ *    self | other_array -> new_array
  *
- *  Set Union --- Returns a new array by joining +ary+ with +other_ary+,
- *  excluding any duplicates and preserving the order from the given arrays.
+ *  Returns the union of +self+ and +other_array+;
+ *  duplicates are removed; order is preserved;
+ *  items are compared using <tt>eql?</tt> and <tt>hash</tt>:
  *
- *  It compares elements using their #hash and #eql? methods for efficiency.
+ *    [0, 1] | [2, 3] # => [0, 1, 2, 3]
+ *    [0, 1, 1] | [2, 2, 3] # => [0, 1, 2, 3]
+ *    [0, 1, 2] | [3, 2, 1, 0] # => [0, 1, 2, 3]
  *
- *     [ "a", "b", "c" ] | [ "c", "d", "a" ]    #=> [ "a", "b", "c", "d" ]
- *     [ "c", "d", "a" ] | [ "a", "b", "c" ]    #=> [ "c", "d", "a", "b" ]
- *
- *  See also Array#union.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
 rb_ary_or(VALUE ary1, VALUE ary2)
 {
-    VALUE hash, ary3;
+    VALUE hash;
 
     ary2 = to_ary(ary2);
     if (RARRAY_LEN(ary1) + RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
-	ary3 = rb_ary_new();
+        VALUE ary3 = rb_ary_new();
         rb_ary_union(ary3, ary1);
         rb_ary_union(ary3, ary2);
-	return ary3;
+        return ary3;
     }
 
     hash = ary_make_hash(ary1);
     rb_ary_union_hash(hash, ary2);
 
-    ary3 = rb_hash_values(hash);
-    ary_recycle_hash(hash);
-    return ary3;
+    return rb_hash_values(hash);
 }
 
 /*
  *  call-seq:
- *     ary.union(other_ary1, other_ary2, ...)   -> new_ary
+ *    union(*other_arrays) -> new_array
  *
- *  Set Union --- Returns a new array by joining <code>other_ary</code>s with +self+,
- *  excluding any duplicates and preserving the order from the given arrays.
+ *  Returns a new array that is the union of the elements of +self+
+ *  and all given arrays +other_arrays+;
+ *  items are compared using <tt>eql?</tt> and <tt>hash</tt>:
  *
- *  It compares elements using their #hash and #eql? methods for efficiency.
+ *    [0, 1, 2, 3].union([4, 5], [6, 7]) # => [0, 1, 2, 3, 4, 5, 6, 7]
  *
- *     [ "a", "b", "c" ].union( [ "c", "d", "a" ] )    #=> [ "a", "b", "c", "d" ]
- *     [ "a" ].union( ["e", "b"], ["a", "c", "b"] )    #=> [ "a", "e", "b", "c" ]
- *     [ "a" ].union #=> [ "a" ]
+ *  Removes duplicates (preserving the first found):
  *
- *  See also Array#|.
+ *    [0, 1, 1].union([2, 1], [3, 1]) # => [0, 1, 2, 3]
+ *
+ *  Preserves order (preserving the position of the first found):
+ *
+ *    [3, 2, 1, 0].union([5, 3], [4, 2]) # => [3, 2, 1, 0, 5, 4]
+ *
+ *  With no arguments given, returns a copy of +self+.
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -4756,7 +5947,7 @@ rb_ary_union_multi(int argc, VALUE *argv, VALUE ary)
 {
     int i;
     long sum;
-    VALUE hash, ary_union;
+    VALUE hash;
 
     sum = RARRAY_LEN(ary);
     for (i = 0; i < argc; i++) {
@@ -4765,7 +5956,7 @@ rb_ary_union_multi(int argc, VALUE *argv, VALUE ary)
     }
 
     if (sum <= SMALL_ARRAY_LEN) {
-        ary_union = rb_ary_new();
+        VALUE ary_union = rb_ary_new();
 
         rb_ary_union(ary_union, ary);
         for (i = 0; i < argc; i++) rb_ary_union(ary_union, argv[i]);
@@ -4776,37 +5967,203 @@ rb_ary_union_multi(int argc, VALUE *argv, VALUE ary)
     hash = ary_make_hash(ary);
     for (i = 0; i < argc; i++) rb_ary_union_hash(hash, argv[i]);
 
-    ary_union = rb_hash_values(hash);
-    ary_recycle_hash(hash);
-    return ary_union;
+    return rb_hash_values(hash);
+}
+
+/*
+ *  call-seq:
+ *    intersect?(other_array) -> true or false
+ *
+ *  Returns whether +other_array+ has at least one element that is +#eql?+ to some element of +self+:
+ *
+ *    [1, 2, 3].intersect?([3, 4, 5]) # => true
+ *    [1, 2, 3].intersect?([4, 5, 6]) # => false
+ *
+ *  Each element must correctly implement method <tt>#hash</tt>.
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
+ */
+
+static VALUE
+rb_ary_intersect_p(VALUE ary1, VALUE ary2)
+{
+    VALUE hash, v, result, shorter, longer;
+    st_data_t vv;
+    long i;
+
+    ary2 = to_ary(ary2);
+    if (RARRAY_LEN(ary1) == 0 || RARRAY_LEN(ary2) == 0) return Qfalse;
+
+    if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN && RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
+        for (i=0; i<RARRAY_LEN(ary1); i++) {
+            v = RARRAY_AREF(ary1, i);
+            if (rb_ary_includes_by_eql(ary2, v)) return Qtrue;
+        }
+        return Qfalse;
+    }
+
+    shorter = ary1;
+    longer = ary2;
+    if (RARRAY_LEN(ary1) > RARRAY_LEN(ary2)) {
+        longer = ary1;
+        shorter = ary2;
+    }
+
+    hash = ary_make_hash(shorter);
+    result = Qfalse;
+
+    for (i=0; i<RARRAY_LEN(longer); i++) {
+        v = RARRAY_AREF(longer, i);
+        vv = (st_data_t)v;
+        if (rb_hash_stlike_lookup(hash, vv, 0)) {
+            result = Qtrue;
+            break;
+        }
+    }
+
+    return result;
+}
+
+static VALUE
+ary_max_generic(VALUE ary, long i, VALUE vmax)
+{
+    RUBY_ASSERT(i > 0 && i < RARRAY_LEN(ary));
+
+    VALUE v;
+    for (; i < RARRAY_LEN(ary); ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (rb_cmpint(rb_funcallv(vmax, id_cmp, 1, &v), vmax, v) < 0) {
+            vmax = v;
+        }
+    }
+
+    return vmax;
+}
+
+static VALUE
+ary_max_opt_fixnum(VALUE ary, long i, VALUE vmax)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(FIXNUM_P(vmax));
+
+    VALUE v;
+    for (; i < n; ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (FIXNUM_P(v)) {
+            if ((long)vmax < (long)v) {
+                vmax = v;
+            }
+        }
+        else {
+            return ary_max_generic(ary, i, vmax);
+        }
+    }
+
+    return vmax;
+}
+
+static VALUE
+ary_max_opt_float(VALUE ary, long i, VALUE vmax)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(RB_FLOAT_TYPE_P(vmax));
+
+    VALUE v;
+    for (; i < n; ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (RB_FLOAT_TYPE_P(v)) {
+            if (rb_float_cmp(vmax, v) < 0) {
+                vmax = v;
+            }
+        }
+        else {
+            return ary_max_generic(ary, i, vmax);
+        }
+    }
+
+    return vmax;
+}
+
+static VALUE
+ary_max_opt_string(VALUE ary, long i, VALUE vmax)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(STRING_P(vmax));
+
+    VALUE v;
+    for (; i < n; ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (STRING_P(v)) {
+            if (rb_str_cmp(vmax, v) < 0) {
+                vmax = v;
+            }
+        }
+        else {
+            return ary_max_generic(ary, i, vmax);
+        }
+    }
+
+    return vmax;
 }
 
 /*
  *  call-seq:
- *     ary.max                     -> obj
- *     ary.max {|a, b| block}      -> obj
- *     ary.max(n)                  -> array
- *     ary.max(n) {|a, b| block}   -> array
+ *    max -> element
+ *    max(count) -> new_array
+ *    max {|a, b| ... } -> element
+ *    max(count) {|a, b| ... } -> new_array
+ *
+ *  Returns one of the following:
+ *
+ *  - The maximum-valued element from +self+.
+ *  - A new array of maximum-valued elements from +self+.
+ *
+ *  Does not modify +self+.
+ *
+ *  With no block given, each element in +self+ must respond to method <tt>#<=></tt>
+ *  with a numeric.
+ *
+ *  With no argument and no block, returns the element in +self+
+ *  having the maximum value per method <tt>#<=></tt>:
  *
- *  Returns the object in _ary_ with the maximum value. The
- *  first form assumes all objects implement Comparable;
- *  the second uses the block to return <em>a <=> b</em>.
+ *    [1, 0, 3, 2].max # => 3
  *
- *     ary = %w(albatross dog horse)
- *     ary.max                                   #=> "horse"
- *     ary.max {|a, b| a.length <=> b.length}    #=> "albatross"
+ *  With non-negative numeric argument +count+ and no block,
+ *  returns a new array with at most +count+ elements,
+ *  in descending order, per method <tt>#<=></tt>:
  *
- *  If the +n+ argument is given, maximum +n+ elements are returned
- *  as an array.
+ *    [1, 0, 3, 2].max(3)   # => [3, 2, 1]
+ *    [1, 0, 3, 2].max(3.0) # => [3, 2, 1]
+ *    [1, 0, 3, 2].max(9)   # => [3, 2, 1, 0]
+ *    [1, 0, 3, 2].max(0)   # => []
  *
- *     ary = %w[albatross dog horse]
- *     ary.max(2)                                  #=> ["horse", "dog"]
- *     ary.max(2) {|a, b| a.length <=> b.length }  #=> ["albatross", "horse"]
+ *  With a block given, the block must return a numeric.
+ *
+ *  With a block and no argument, calls the block <tt>self.size - 1</tt> times to compare elements;
+ *  returns the element having the maximum value per the block:
+ *
+ *    ['0', '', '000', '00'].max {|a, b| a.size <=> b.size }
+ *    # => "000"
+ *
+ *  With non-negative numeric argument +count+ and a block,
+ *  returns a new array with at most +count+ elements,
+ *  in descending order, per the block:
+ *
+ *    ['0', '', '000', '00'].max(2) {|a, b| a.size <=> b.size }
+ *    # => ["000", "00"]
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 static VALUE
 rb_ary_max(int argc, VALUE *argv, VALUE ary)
 {
-    struct cmp_opt_data cmp_opt = { 0, 0 };
     VALUE result = Qundef, v;
     VALUE num;
     long i;
@@ -4814,52 +6171,176 @@ rb_ary_max(int argc, VALUE *argv, VALUE ary)
     if (rb_check_arity(argc, 0, 1) && !NIL_P(num = argv[0]))
        return rb_nmin_run(ary, num, 0, 1, 1);
 
+    const long n = RARRAY_LEN(ary);
     if (rb_block_given_p()) {
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	   v = RARRAY_AREF(ary, i);
-	   if (result == Qundef || rb_cmpint(rb_yield_values(2, v, result), v, result) > 0) {
-	       result = v;
-	   }
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+           v = RARRAY_AREF(ary, i);
+           if (UNDEF_P(result) || rb_cmpint(rb_yield_values(2, v, result), v, result) > 0) {
+               result = v;
+           }
+        }
     }
-    else {
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	   v = RARRAY_AREF(ary, i);
-	   if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) > 0) {
-	       result = v;
-	   }
-	}
-    }
-    if (result == Qundef) return Qnil;
+    else if (n > 0) {
+        result = RARRAY_AREF(ary, 0);
+        if (n > 1) {
+            if (FIXNUM_P(result) && CMP_OPTIMIZABLE(INTEGER)) {
+                return ary_max_opt_fixnum(ary, 1, result);
+            }
+            else if (STRING_P(result) && CMP_OPTIMIZABLE(STRING)) {
+                return ary_max_opt_string(ary, 1, result);
+            }
+            else if (RB_FLOAT_TYPE_P(result) && CMP_OPTIMIZABLE(FLOAT)) {
+                return ary_max_opt_float(ary, 1, result);
+            }
+            else {
+                return ary_max_generic(ary, 1, result);
+            }
+        }
+    }
+    if (UNDEF_P(result)) return Qnil;
     return result;
 }
 
+static VALUE
+ary_min_generic(VALUE ary, long i, VALUE vmin)
+{
+    RUBY_ASSERT(i > 0 && i < RARRAY_LEN(ary));
+
+    VALUE v;
+    for (; i < RARRAY_LEN(ary); ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (rb_cmpint(rb_funcallv(vmin, id_cmp, 1, &v), vmin, v) > 0) {
+            vmin = v;
+        }
+    }
+
+    return vmin;
+}
+
+static VALUE
+ary_min_opt_fixnum(VALUE ary, long i, VALUE vmin)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(FIXNUM_P(vmin));
+
+    VALUE a;
+    for (; i < n; ++i) {
+        a = RARRAY_AREF(ary, i);
+
+        if (FIXNUM_P(a)) {
+            if ((long)vmin > (long)a) {
+                vmin = a;
+            }
+        }
+        else {
+            return ary_min_generic(ary, i, vmin);
+        }
+    }
+
+    return vmin;
+}
+
+static VALUE
+ary_min_opt_float(VALUE ary, long i, VALUE vmin)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(RB_FLOAT_TYPE_P(vmin));
+
+    VALUE a;
+    for (; i < n; ++i) {
+        a = RARRAY_AREF(ary, i);
+
+        if (RB_FLOAT_TYPE_P(a)) {
+            if (rb_float_cmp(vmin, a) > 0) {
+                vmin = a;
+            }
+        }
+        else {
+            return ary_min_generic(ary, i, vmin);
+        }
+    }
+
+    return vmin;
+}
+
+static VALUE
+ary_min_opt_string(VALUE ary, long i, VALUE vmin)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(STRING_P(vmin));
+
+    VALUE a;
+    for (; i < n; ++i) {
+        a = RARRAY_AREF(ary, i);
+
+        if (STRING_P(a)) {
+            if (rb_str_cmp(vmin, a) > 0) {
+                vmin = a;
+            }
+        }
+        else {
+            return ary_min_generic(ary, i, vmin);
+        }
+    }
+
+    return vmin;
+}
+
 /*
  *  call-seq:
- *     ary.min                     -> obj
- *     ary.min {| a,b | block }    -> obj
- *     ary.min(n)                  -> array
- *     ary.min(n) {| a,b | block } -> array
+ *    min -> element
+ *    min(count) -> new_array
+ *    min {|a, b| ... } -> element
+ *    min(count) {|a, b| ... } -> new_array
+ *
+ *  Returns one of the following:
+ *
+ *  - The minimum-valued element from +self+.
+ *  - A new array of minimum-valued elements from +self+.
+ *
+ *  Does not modify +self+.
+ *
+ *  With no block given, each element in +self+ must respond to method <tt>#<=></tt>
+ *  with a numeric.
+ *
+ *  With no argument and no block, returns the element in +self+
+ *  having the minimum value per method <tt>#<=></tt>:
  *
- *  Returns the object in _ary_ with the minimum value. The
- *  first form assumes all objects implement Comparable;
- *  the second uses the block to return <em>a <=> b</em>.
+ *    [1, 0, 3, 2].min # => 0
  *
- *     ary = %w(albatross dog horse)
- *     ary.min                                   #=> "albatross"
- *     ary.min {|a, b| a.length <=> b.length}    #=> "dog"
+ *  With non-negative numeric argument +count+ and no block,
+ *  returns a new array with at most +count+ elements,
+ *  in ascending order, per method <tt>#<=></tt>:
  *
- *  If the +n+ argument is given, minimum +n+ elements are returned
- *  as an array.
+ *    [1, 0, 3, 2].min(3)   # => [0, 1, 2]
+ *    [1, 0, 3, 2].min(3.0) # => [0, 1, 2]
+ *    [1, 0, 3, 2].min(9)   # => [0, 1, 2, 3]
+ *    [1, 0, 3, 2].min(0)   # => []
  *
- *     ary = %w[albatross dog horse]
- *     ary.min(2)                                  #=> ["albatross", "dog"]
- *     ary.min(2) {|a, b| a.length <=> b.length }  #=> ["dog", "horse"]
+ *  With a block given, the block must return a numeric.
+ *
+ *  With a block and no argument, calls the block <tt>self.size - 1</tt> times to compare elements;
+ *  returns the element having the minimum value per the block:
+ *
+ *    ['0', '', '000', '00'].min {|a, b| a.size <=> b.size }
+ *    # => ""
+ *
+ *  With non-negative numeric argument +count+ and a block,
+ *  returns a new array with at most +count+ elements,
+ *  in ascending order, per the block:
+ *
+ *    ['0', '', '000', '00'].min(2) {|a, b| a.size <=> b.size }
+ *    # => ["", "0"]
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 static VALUE
 rb_ary_min(int argc, VALUE *argv, VALUE ary)
 {
-    struct cmp_opt_data cmp_opt = { 0, 0 };
     VALUE result = Qundef, v;
     VALUE num;
     long i;
@@ -4867,36 +6348,57 @@ rb_ary_min(int argc, VALUE *argv, VALUE ary)
     if (rb_check_arity(argc, 0, 1) && !NIL_P(num = argv[0]))
        return rb_nmin_run(ary, num, 0, 0, 1);
 
+    const long n = RARRAY_LEN(ary);
     if (rb_block_given_p()) {
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	   v = RARRAY_AREF(ary, i);
-	   if (result == Qundef || rb_cmpint(rb_yield_values(2, v, result), v, result) < 0) {
-	       result = v;
-	   }
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+           v = RARRAY_AREF(ary, i);
+           if (UNDEF_P(result) || rb_cmpint(rb_yield_values(2, v, result), v, result) < 0) {
+               result = v;
+           }
+        }
     }
-    else {
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	   v = RARRAY_AREF(ary, i);
-	   if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) < 0) {
-	       result = v;
-	   }
-	}
-    }
-    if (result == Qundef) return Qnil;
+    else if (n > 0) {
+        result = RARRAY_AREF(ary, 0);
+        if (n > 1) {
+            if (FIXNUM_P(result) && CMP_OPTIMIZABLE(INTEGER)) {
+                return ary_min_opt_fixnum(ary, 1, result);
+            }
+            else if (STRING_P(result) && CMP_OPTIMIZABLE(STRING)) {
+                return ary_min_opt_string(ary, 1, result);
+            }
+            else if (RB_FLOAT_TYPE_P(result) && CMP_OPTIMIZABLE(FLOAT)) {
+                return ary_min_opt_float(ary, 1, result);
+            }
+            else {
+                return ary_min_generic(ary, 1, result);
+            }
+        }
+    }
+    if (UNDEF_P(result)) return Qnil;
     return result;
 }
 
 /*
  *  call-seq:
- *     ary.minmax                       -> [obj, obj]
- *     ary.minmax {| a,b | block }      -> [obj, obj]
+ *    minmax -> array
+ *    minmax {|a, b| ... } -> array
+ *
+ *  Returns a 2-element array containing the minimum-valued and maximum-valued
+ *  elements from +self+;
+ *  does not modify +self+.
+ *
+ *  With no block given, the minimum and maximum values are determined using method <tt>#<=></tt>:
+ *
+ *    [1, 0, 3, 2].minmax # => [0, 3]
+ *
+ *  With a block given, the block must return a numeric;
+ *  the block is called <tt>self.size - 1</tt> times to compare elements;
+ *  returns the elements having the minimum and maximum values per the block:
  *
- *  Returns a two element array which contains the minimum and the
- *  maximum value in the array.
+ *    ['0', '', '000', '00'].minmax {|a, b| a.size <=> b.size }
+ *    # => ["", "000"]
  *
- *  Can be given an optional block to override the default comparison
- *  method <code>a <=> b</code>.
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 static VALUE
 rb_ary_minmax(VALUE ary)
@@ -4916,31 +6418,31 @@ push_value(st_data_t key, st_data_t val, st_data_t ary)
 
 /*
  *  call-seq:
- *     ary.uniq!                -> ary or nil
- *     ary.uniq! {|item| ...}   -> ary or nil
+ *    uniq! -> self or nil
+ *    uniq! {|element| ... } -> self or nil
  *
- *  Removes duplicate elements from +self+.
+ *  Removes duplicate elements from +self+, the first occurrence always being retained;
+ *  returns +self+ if any elements removed, +nil+ otherwise.
  *
- *  If a block is given, it will use the return value of the block for
- *  comparison.
+ *  With no block given, identifies and removes elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare elements:
  *
- *  It compares values using their #hash and #eql? methods for efficiency.
+ *    a = [0, 0, 1, 1, 2, 2]
+ *    a.uniq! # => [0, 1, 2]
+ *    a.uniq! # => nil
  *
- *  +self+ is traversed in order, and the first occurrence is kept.
+ *  With a block given, calls the block for each element;
+ *  identifies and omits "duplicate" elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare <i>block return values</i>;
+ *  that is, an element is a duplicate if its block return value
+ *  is the same as that of a previous element:
  *
- *  Returns +nil+ if no changes are made (that is, no duplicates are found).
- *
- *     a = [ "a", "a", "b", "b", "c" ]
- *     a.uniq!   # => ["a", "b", "c"]
- *
- *     b = [ "a", "b", "c" ]
- *     b.uniq!   # => nil
- *
- *     c = [["student","sam"], ["student","george"], ["teacher","matz"]]
- *     c.uniq! {|s| s.first}   # => [["student", "sam"], ["teacher", "matz"]]
+ *    a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb']
+ *    a.uniq! {|element| element.size } # => ["a", "aa", "aaa"]
+ *    a.uniq! {|element| element.size } # => nil
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
-
 static VALUE
 rb_ary_uniq_bang(VALUE ary)
 {
@@ -4951,46 +6453,50 @@ rb_ary_uniq_bang(VALUE ary)
     if (RARRAY_LEN(ary) <= 1)
         return Qnil;
     if (rb_block_given_p())
-	hash = ary_make_hash_by(ary);
+        hash = ary_make_hash_by(ary);
     else
-	hash = ary_make_hash(ary);
+        hash = ary_make_hash(ary);
 
     hash_size = RHASH_SIZE(hash);
     if (RARRAY_LEN(ary) == hash_size) {
-	return Qnil;
+        return Qnil;
     }
     rb_ary_modify_check(ary);
     ARY_SET_LEN(ary, 0);
-    if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
-	rb_ary_unshare(ary);
-	FL_SET_EMBED(ary);
+    if (ARY_SHARED_P(ary)) {
+        rb_ary_unshare(ary);
+        FL_SET_EMBED(ary);
     }
     ary_resize_capa(ary, hash_size);
     rb_hash_foreach(hash, push_value, ary);
-    ary_recycle_hash(hash);
 
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.uniq                -> new_ary
- *     ary.uniq {|item| ...}   -> new_ary
- *
- *  Returns a new array by removing duplicate values in +self+.
+ *    uniq -> new_array
+ *    uniq {|element| ... } -> new_array
  *
- *  If a block is given, it will use the return value of the block for comparison.
+ *  Returns a new array containing those elements from +self+ that are not duplicates,
+ *  the first occurrence always being retained.
  *
- *  It compares values using their #hash and #eql? methods for efficiency.
+ *  With no block given, identifies and omits duplicate elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare elements:
  *
- *  +self+ is traversed in order, and the first occurrence is kept.
+ *    a = [0, 0, 1, 1, 2, 2]
+ *    a.uniq # => [0, 1, 2]
  *
- *     a = [ "a", "a", "b", "b", "c" ]
- *     a.uniq   # => ["a", "b", "c"]
+ *  With a block given, calls the block for each element;
+ *  identifies and omits "duplicate" elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare <i>block return values</i>;
+ *  that is, an element is a duplicate if its block return value
+ *  is the same as that of a previous element:
  *
- *     b = [["student","sam"], ["student","george"], ["teacher","matz"]]
- *     b.uniq {|s| s.first}   # => [["student", "sam"], ["teacher", "matz"]]
+ *    a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb']
+ *    a.uniq {|element| element.size } # => ["a", "aa", "aaa"]
  *
+ *  Related: {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -5003,16 +6509,12 @@ rb_ary_uniq(VALUE ary)
         uniq = rb_ary_dup(ary);
     }
     else if (rb_block_given_p()) {
-	hash = ary_make_hash_by(ary);
-	uniq = rb_hash_values(hash);
+        hash = ary_make_hash_by(ary);
+        uniq = rb_hash_values(hash);
     }
     else {
-	hash = ary_make_hash(ary);
-	uniq = rb_hash_values(hash);
-    }
-    RBASIC_SET_CLASS(uniq, rb_obj_class(ary));
-    if (hash) {
-        ary_recycle_hash(hash);
+        hash = ary_make_hash(ary);
+        uniq = rb_hash_values(hash);
     }
 
     return uniq;
@@ -5020,33 +6522,37 @@ rb_ary_uniq(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.compact!    -> ary  or  nil
+ *    compact! -> self or nil
  *
- *  Removes +nil+ elements from the array.
+ *  Removes all +nil+ elements from +self+;
+ *  Returns +self+ if any elements are removed, +nil+ otherwise:
  *
- *  Returns +nil+ if no changes were made, otherwise returns the array.
+ *    a = [nil, 0, nil, false, nil, '', nil, [], nil, {}]
+ *    a.compact! # => [0, false, "", [], {}]
+ *    a          # => [0, false, "", [], {}]
+ *    a.compact! # => nil
  *
- *     [ "a", nil, "b", nil, "c" ].compact! #=> [ "a", "b", "c" ]
- *     [ "a", "b", "c" ].compact!           #=> nil
+ *  Related: Array#compact;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
-static VALUE
+VALUE
 rb_ary_compact_bang(VALUE ary)
 {
     VALUE *p, *t, *end;
     long n;
 
     rb_ary_modify(ary);
-    p = t = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary); /* WB: no new reference */
+    p = t = (VALUE *)RARRAY_CONST_PTR(ary); /* WB: no new reference */
     end = p + RARRAY_LEN(ary);
 
     while (t < end) {
-	if (NIL_P(*t)) t++;
-	else *p++ = *t++;
+        if (NIL_P(*t)) t++;
+        else *p++ = *t++;
     }
-    n = p - RARRAY_CONST_PTR_TRANSIENT(ary);
+    n = p - RARRAY_CONST_PTR(ary);
     if (RARRAY_LEN(ary) == n) {
-	return Qnil;
+        return Qnil;
     }
     ary_resize_smaller(ary, n);
 
@@ -5055,12 +6561,16 @@ rb_ary_compact_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.compact     -> new_ary
+ *    compact -> new_array
  *
- *  Returns a copy of +self+ with all +nil+ elements removed.
+ *  Returns a new array containing only the non-+nil+ elements from +self+;
+ *  element order is preserved:
  *
- *     [ "a", nil, "b", nil, "c", nil ].compact
- *                       #=> [ "a", "b", "c" ]
+ *    a = [nil, 0, nil, false, nil, '', nil, [], nil, {}]
+ *    a.compact # => [0, false, "", [], {}]
+ *
+ *  Related: Array#compact!;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -5073,23 +6583,29 @@ rb_ary_compact(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.count                   -> int
- *     ary.count(obj)              -> int
- *     ary.count {|item| block}    -> int
+ *    count -> integer
+ *    count(object) -> integer
+ *    count {|element| ... } -> integer
+ *
+ *  Returns a count of specified elements.
+ *
+ *  With no argument and no block, returns the count of all elements:
  *
- *  Returns the number of elements.
+ *    [0, :one, 'two', 3, 3.0].count # => 5
  *
- *  If an argument is given, counts the number of elements which equal +obj+
- *  using <code>==</code>.
+ *  With argument +object+ given, returns the count of elements <tt>==</tt> to +object+:
  *
- *  If a block is given, counts the number of elements for which the block
- *  returns a true value.
+ *    [0, :one, 'two', 3, 3.0].count(3) # => 2
  *
- *     ary = [1, 2, 4, 2]
- *     ary.count                  #=> 4
- *     ary.count(2)               #=> 2
- *     ary.count {|x| x%2 == 0}   #=> 3
+ *  With no argument and a block given, calls the block with each element;
+ *  returns the count of elements for which the block returns a truthy value:
  *
+ *    [0, 1, 2, 3].count {|element| element > 1 } # => 2
+ *
+ *  With argument +object+ and a block given, issues a warning, ignores the block,
+ *  and returns the count of elements <tt>==</tt> to +object+.
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -5098,25 +6614,25 @@ rb_ary_count(int argc, VALUE *argv, VALUE ary)
     long i, n = 0;
 
     if (rb_check_arity(argc, 0, 1) == 0) {
-	VALUE v;
+        VALUE v;
 
-	if (!rb_block_given_p())
-	    return LONG2NUM(RARRAY_LEN(ary));
+        if (!rb_block_given_p())
+            return LONG2NUM(RARRAY_LEN(ary));
 
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	    v = RARRAY_AREF(ary, i);
-	    if (RTEST(rb_yield(v))) n++;
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+            v = RARRAY_AREF(ary, i);
+            if (RTEST(rb_yield(v))) n++;
+        }
     }
     else {
         VALUE obj = argv[0];
 
-	if (rb_block_given_p()) {
-	    rb_warn("given block not used");
-	}
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	    if (rb_equal(RARRAY_AREF(ary, i), obj)) n++;
-	}
+        if (rb_block_given_p()) {
+            rb_warn("given block not used");
+        }
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+            if (rb_equal(RARRAY_AREF(ary, i), obj)) n++;
+        }
     }
 
     return LONG2NUM(n);
@@ -5126,9 +6642,8 @@ static VALUE
 flatten(VALUE ary, int level)
 {
     long i;
-    VALUE stack, result, tmp, elt, vmemo;
-    st_table *memo;
-    st_data_t id;
+    VALUE stack, result, tmp = 0, elt;
+    VALUE memo = Qfalse;
 
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         elt = RARRAY_AREF(ary, i);
@@ -5139,91 +6654,108 @@ flatten(VALUE ary, int level)
     }
     if (i == RARRAY_LEN(ary)) {
         return ary;
-    } else if (tmp == ary) {
-        rb_raise(rb_eArgError, "tried to flatten recursive array");
     }
 
     result = ary_new(0, RARRAY_LEN(ary));
-    ary_memcpy(result, 0, i, RARRAY_CONST_PTR_TRANSIENT(ary));
+    ary_memcpy(result, 0, i, RARRAY_CONST_PTR(ary));
     ARY_SET_LEN(result, i);
 
     stack = ary_new(0, ARY_DEFAULT_SIZE);
     rb_ary_push(stack, ary);
     rb_ary_push(stack, LONG2NUM(i + 1));
 
-    vmemo = rb_hash_new();
-    RBASIC_CLEAR_CLASS(vmemo);
-    memo = st_init_numtable();
-    rb_hash_st_table_set(vmemo, memo);
-    st_insert(memo, (st_data_t)ary, (st_data_t)Qtrue);
-    st_insert(memo, (st_data_t)tmp, (st_data_t)Qtrue);
+    if (level < 0) {
+        memo = rb_obj_hide(rb_ident_hash_new());
+        rb_hash_aset(memo, ary, Qtrue);
+        rb_hash_aset(memo, tmp, Qtrue);
+    }
 
     ary = tmp;
     i = 0;
 
     while (1) {
-	while (i < RARRAY_LEN(ary)) {
-	    elt = RARRAY_AREF(ary, i++);
-	    if (level >= 0 && RARRAY_LEN(stack) / 2 >= level) {
-		rb_ary_push(result, elt);
-		continue;
-	    }
-	    tmp = rb_check_array_type(elt);
-	    if (RBASIC(result)->klass) {
-                RB_GC_GUARD(vmemo);
-                st_clear(memo);
-		rb_raise(rb_eRuntimeError, "flatten reentered");
-	    }
-	    if (NIL_P(tmp)) {
-		rb_ary_push(result, elt);
-	    }
-	    else {
-		id = (st_data_t)tmp;
-		if (st_lookup(memo, id, 0)) {
-                    st_clear(memo);
-		    rb_raise(rb_eArgError, "tried to flatten recursive array");
-		}
-		st_insert(memo, id, (st_data_t)Qtrue);
-		rb_ary_push(stack, ary);
-		rb_ary_push(stack, LONG2NUM(i));
-		ary = tmp;
-		i = 0;
-	    }
-	}
-	if (RARRAY_LEN(stack) == 0) {
-	    break;
-	}
-	id = (st_data_t)ary;
-	st_delete(memo, &id, 0);
-	tmp = rb_ary_pop(stack);
-	i = NUM2LONG(tmp);
-	ary = rb_ary_pop(stack);
-    }
-
-    st_clear(memo);
-
-    RBASIC_SET_CLASS(result, rb_obj_class(ary));
+        while (i < RARRAY_LEN(ary)) {
+            elt = RARRAY_AREF(ary, i++);
+            if (level >= 0 && RARRAY_LEN(stack) / 2 >= level) {
+                rb_ary_push(result, elt);
+                continue;
+            }
+            tmp = rb_check_array_type(elt);
+            if (RBASIC(result)->klass) {
+                if (RTEST(memo)) {
+                    rb_hash_clear(memo);
+                }
+                rb_raise(rb_eRuntimeError, "flatten reentered");
+            }
+            if (NIL_P(tmp)) {
+                rb_ary_push(result, elt);
+            }
+            else {
+                if (memo) {
+                    if (rb_hash_aref(memo, tmp) == Qtrue) {
+                        rb_hash_clear(memo);
+                        rb_raise(rb_eArgError, "tried to flatten recursive array");
+                    }
+                    rb_hash_aset(memo, tmp, Qtrue);
+                }
+                rb_ary_push(stack, ary);
+                rb_ary_push(stack, LONG2NUM(i));
+                ary = tmp;
+                i = 0;
+            }
+        }
+        if (RARRAY_LEN(stack) == 0) {
+            break;
+        }
+        if (memo) {
+            rb_hash_delete(memo, ary);
+        }
+        tmp = rb_ary_pop(stack);
+        i = NUM2LONG(tmp);
+        ary = rb_ary_pop(stack);
+    }
+
+    if (memo) {
+        rb_hash_clear(memo);
+    }
+
+    RBASIC_SET_CLASS(result, rb_cArray);
     return result;
 }
 
 /*
  *  call-seq:
- *     ary.flatten!        -> ary or nil
- *     ary.flatten!(level) -> ary or nil
+ *    flatten!(depth = nil) -> self or nil
+ *
+ *  Returns +self+ as a recursively flattening of +self+ to +depth+ levels of recursion;
+ *  +depth+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects],
+ *  or +nil+.
+ *  At each level of recursion:
+ *
+ *  - Each element that is an array is "flattened"
+ *    (that is, replaced by its individual array elements).
+ *  - Each element that is not an array is unchanged
+ *    (even if the element is an object that has instance method +flatten+).
  *
- *  Flattens +self+ in place.
+ *  Returns +nil+ if no elements were flattened.
  *
- *  Returns +nil+ if no modifications were made (i.e., the array contains no
- *  subarrays.)
+ *  With non-negative integer argument +depth+, flattens recursively through +depth+ levels:
  *
- *  The optional +level+ argument determines the level of recursion to flatten.
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5, {foo: 0}, Set.new([6, 7]) ]
+ *    a                   # => [0, [1, [2, 3], 4], 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(1)   # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(1.1) # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(2)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(3)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
  *
- *     a = [ 1, 2, [3, [4, 5] ] ]
- *     a.flatten!   #=> [1, 2, 3, 4, 5]
- *     a.flatten!   #=> nil
- *     a            #=> [1, 2, 3, 4, 5]
- *     a = [ 1, 2, [3, [4, 5] ] ]
- *     a.flatten!(1) #=> [1, 2, 3, [4, 5]]
+ *  With +nil+ or negative argument +depth+, flattens all levels:
+ *
+ *    a.dup.flatten!     # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(-1) # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *
+ *  Related: Array#flatten;
+ *  see also {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -5239,9 +6771,9 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
 
     result = flatten(ary, level);
     if (result == ary) {
-	return Qnil;
+        return Qnil;
     }
-    if (!(mod = ARY_EMBED_P(result))) rb_obj_freeze(result);
+    if (!(mod = ARY_EMBED_P(result))) rb_ary_freeze(result);
     rb_ary_replace(ary, result);
     if (mod) ARY_SET_EMBED_LEN(result, 0);
 
@@ -5250,24 +6782,37 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.flatten -> new_ary
- *     ary.flatten(level) -> new_ary
+ *    flatten(depth = nil) -> new_array
+ *
+ *  Returns a new array that is a recursive flattening of +self+
+ *  to +depth+ levels of recursion;
+ *  +depth+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]
+ *  or +nil+.
+ *  At each level of recursion:
+ *
+ *  - Each element that is an array is "flattened"
+ *    (that is, replaced by its individual array elements).
+ *  - Each element that is not an array is unchanged
+ *    (even if the element is an object that has instance method +flatten+).
+ *
+ *  With non-negative integer argument +depth+, flattens recursively through +depth+ levels:
  *
- *  Returns a new array that is a one-dimensional flattening of +self+
- *  (recursively).
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5, {foo: 0}, Set.new([6, 7]) ]
+ *    a              # => [0, [1, [2, 3], 4], 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(0)   # => [0, [1, [2, 3], 4], 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(1  ) # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(1.1) # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(2)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(3)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
  *
- *  That is, for every element that is an array, extract its elements into
- *  the new array.
+ *  With +nil+ or negative +depth+, flattens all levels.
  *
- *  The optional +level+ argument determines the level of recursion to
- *  flatten.
+ *    a.flatten     # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(-1) # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
  *
- *     s = [ 1, 2, 3 ]           #=> [1, 2, 3]
- *     t = [ 4, 5, 6, [7, 8] ]   #=> [4, 5, 6, [7, 8]]
- *     a = [ s, t, 9, 10 ]       #=> [[1, 2, 3], [4, 5, 6, [7, 8]], 9, 10]
- *     a.flatten                 #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
- *     a = [ 1, 2, [3, [4, 5] ] ]
- *     a.flatten(1)              #=> [1, 2, 3, [4, 5]]
+ *  Related: Array#flatten!;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -5285,256 +6830,173 @@ rb_ary_flatten(int argc, VALUE *argv, VALUE ary)
     if (result == ary) {
         result = ary_make_shared_copy(ary);
     }
-    OBJ_INFECT(result, ary);
 
     return result;
 }
 
-#define OPTHASH_GIVEN_P(opts) \
-    (argc > 0 && !NIL_P((opts) = rb_check_hash_type(argv[argc-1])) && (--argc, 1))
-static ID id_random;
-
 #define RAND_UPTO(max) (long)rb_random_ulong_limited((randgen), (max)-1)
 
-/*
- *  call-seq:
- *     ary.shuffle!              -> ary
- *     ary.shuffle!(random: rng) -> ary
- *
- *  Shuffles elements in +self+ in place.
- *
- *     a = [ 1, 2, 3 ]           #=> [1, 2, 3]
- *     a.shuffle!                #=> [2, 3, 1]
- *     a                         #=> [2, 3, 1]
- *
- *  The optional +rng+ argument will be used as the random number generator.
- *
- *     a.shuffle!(random: Random.new(1))  #=> [1, 3, 2]
- */
-
 static VALUE
-rb_ary_shuffle_bang(int argc, VALUE *argv, VALUE ary)
+rb_ary_shuffle_bang(rb_execution_context_t *ec, VALUE ary, VALUE randgen)
 {
-    VALUE opts, randgen = rb_cRandom;
     long i, len;
 
-    if (OPTHASH_GIVEN_P(opts)) {
-	VALUE rnd;
-	ID keyword_ids[1];
-
-	keyword_ids[0] = id_random;
-	rb_get_kwargs(opts, keyword_ids, 0, 1, &rnd);
-	if (rnd != Qundef) {
-	    randgen = rnd;
-	}
-    }
-    rb_check_arity(argc, 0, 0);
     rb_ary_modify(ary);
     i = len = RARRAY_LEN(ary);
     RARRAY_PTR_USE(ary, ptr, {
-	while (i) {
-	    long j = RAND_UPTO(i);
-	    VALUE tmp;
-            if (len != RARRAY_LEN(ary) || ptr != RARRAY_CONST_PTR_TRANSIENT(ary)) {
+        while (i > 1) {
+            long j = RAND_UPTO(i);
+            VALUE tmp;
+            if (len != RARRAY_LEN(ary) || ptr != RARRAY_CONST_PTR(ary)) {
                 rb_raise(rb_eRuntimeError, "modified during shuffle");
-	    }
-	    tmp = ptr[--i];
-	    ptr[i] = ptr[j];
-	    ptr[j] = tmp;
-	}
+            }
+            tmp = ptr[--i];
+            ptr[i] = ptr[j];
+            ptr[j] = tmp;
+        }
     }); /* WB: no new reference */
     return ary;
 }
 
-
-/*
- *  call-seq:
- *     ary.shuffle              -> new_ary
- *     ary.shuffle(random: rng) -> new_ary
- *
- *  Returns a new array with elements of +self+ shuffled.
- *
- *     a = [ 1, 2, 3 ]           #=> [1, 2, 3]
- *     a.shuffle                 #=> [2, 3, 1]
- *     a                         #=> [1, 2, 3]
- *
- *  The optional +rng+ argument will be used as the random number generator.
- *
- *     a.shuffle(random: Random.new(1))  #=> [1, 3, 2]
- */
-
 static VALUE
-rb_ary_shuffle(int argc, VALUE *argv, VALUE ary)
+rb_ary_shuffle(rb_execution_context_t *ec, VALUE ary, VALUE randgen)
 {
     ary = rb_ary_dup(ary);
-    rb_ary_shuffle_bang(argc, argv, ary);
+    rb_ary_shuffle_bang(ec, ary, randgen);
     return ary;
 }
 
-
-/*
- *  call-seq:
- *     ary.sample                  -> obj
- *     ary.sample(random: rng)     -> obj
- *     ary.sample(n)               -> new_ary
- *     ary.sample(n, random: rng)  -> new_ary
- *
- *  Choose a random element or +n+ random elements from the array.
- *
- *  The elements are chosen by using random and unique indices into the array
- *  in order to ensure that an element doesn't repeat itself unless the array
- *  already contained duplicate elements.
- *
- *  If the array is empty the first form returns +nil+ and the second form
- *  returns an empty array.
- *
- *     a = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
- *     a.sample         #=> 7
- *     a.sample(4)      #=> [6, 4, 2, 5]
- *
- *  The optional +rng+ argument will be used as the random number generator.
- *
- *     a.sample(random: Random.new(1))     #=> 6
- *     a.sample(4, random: Random.new(1))  #=> [6, 10, 9, 2]
- */
-
+static const rb_data_type_t ary_sample_memo_type = {
+    .wrap_struct_name = "ary_sample_memo",
+    .function = {
+        .dfree = (RUBY_DATA_FUNC)st_free_table,
+    },
+    .flags = RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FREE_IMMEDIATELY
+};
 
 static VALUE
-rb_ary_sample(int argc, VALUE *argv, VALUE ary)
+ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE to_array)
 {
-    VALUE nv, result;
-    VALUE opts, randgen = rb_cRandom;
+    VALUE result;
     long n, len, i, j, k, idx[10];
     long rnds[numberof(idx)];
     long memo_threshold;
 
-    if (OPTHASH_GIVEN_P(opts)) {
-	VALUE rnd;
-	ID keyword_ids[1];
-
-	keyword_ids[0] = id_random;
-	rb_get_kwargs(opts, keyword_ids, 0, 1, &rnd);
-	if (rnd != Qundef) {
-	    randgen = rnd;
-	}
-    }
     len = RARRAY_LEN(ary);
-    if (rb_check_arity(argc, 0, 1) == 0) {
-	if (len < 2)
-	    i = 0;
-	else
-	    i = RAND_UPTO(len);
+    if (!to_array) {
+        if (len < 2)
+            i = 0;
+        else
+            i = RAND_UPTO(len);
 
-	return rb_ary_elt(ary, i);
+        return rb_ary_elt(ary, i);
     }
-    nv = argv[0];
     n = NUM2LONG(nv);
     if (n < 0) rb_raise(rb_eArgError, "negative sample number");
     if (n > len) n = len;
     if (n <= numberof(idx)) {
-	for (i = 0; i < n; ++i) {
-	    rnds[i] = RAND_UPTO(len - i);
-	}
+        for (i = 0; i < n; ++i) {
+            rnds[i] = RAND_UPTO(len - i);
+        }
     }
     k = len;
     len = RARRAY_LEN(ary);
     if (len < k && n <= numberof(idx)) {
-	for (i = 0; i < n; ++i) {
-	    if (rnds[i] >= len) return rb_ary_new_capa(0);
-	}
+        for (i = 0; i < n; ++i) {
+            if (rnds[i] >= len) return rb_ary_new_capa(0);
+        }
     }
     if (n > len) n = len;
     switch (n) {
       case 0:
-	return rb_ary_new_capa(0);
+        return rb_ary_new_capa(0);
       case 1:
-	i = rnds[0];
-	return rb_ary_new_from_values(1, &RARRAY_AREF(ary, i));
+        i = rnds[0];
+        return rb_ary_new_from_args(1, RARRAY_AREF(ary, i));
       case 2:
-	i = rnds[0];
-	j = rnds[1];
-	if (j >= i) j++;
-	return rb_ary_new_from_args(2, RARRAY_AREF(ary, i), RARRAY_AREF(ary, j));
+        i = rnds[0];
+        j = rnds[1];
+        if (j >= i) j++;
+        return rb_ary_new_from_args(2, RARRAY_AREF(ary, i), RARRAY_AREF(ary, j));
       case 3:
-	i = rnds[0];
-	j = rnds[1];
-	k = rnds[2];
-	{
-	    long l = j, g = i;
-	    if (j >= i) l = i, g = ++j;
-	    if (k >= l && (++k >= g)) ++k;
-	}
-	return rb_ary_new_from_args(3, RARRAY_AREF(ary, i), RARRAY_AREF(ary, j), RARRAY_AREF(ary, k));
+        i = rnds[0];
+        j = rnds[1];
+        k = rnds[2];
+        {
+            long l = j, g = i;
+            if (j >= i) l = i, g = ++j;
+            if (k >= l && (++k >= g)) ++k;
+        }
+        return rb_ary_new_from_args(3, RARRAY_AREF(ary, i), RARRAY_AREF(ary, j), RARRAY_AREF(ary, k));
     }
     memo_threshold =
-	len < 2560 ? len / 128 :
-	len < 5120 ? len / 64 :
-	len < 10240 ? len / 32 :
-	len / 16;
+        len < 2560 ? len / 128 :
+        len < 5120 ? len / 64 :
+        len < 10240 ? len / 32 :
+        len / 16;
     if (n <= numberof(idx)) {
-	long sorted[numberof(idx)];
-	sorted[0] = idx[0] = rnds[0];
-	for (i=1; i<n; i++) {
-	    k = rnds[i];
-	    for (j = 0; j < i; ++j) {
-		if (k < sorted[j]) break;
-		++k;
-	    }
-	    memmove(&sorted[j+1], &sorted[j], sizeof(sorted[0])*(i-j));
-	    sorted[j] = idx[i] = k;
-	}
-	result = rb_ary_new_capa(n);
-        RARRAY_PTR_USE_TRANSIENT(result, ptr_result, {
-	    for (i=0; i<n; i++) {
-		ptr_result[i] = RARRAY_AREF(ary, idx[i]);
-	    }
-	});
+        long sorted[numberof(idx)];
+        sorted[0] = idx[0] = rnds[0];
+        for (i=1; i<n; i++) {
+            k = rnds[i];
+            for (j = 0; j < i; ++j) {
+                if (k < sorted[j]) break;
+                ++k;
+            }
+            memmove(&sorted[j+1], &sorted[j], sizeof(sorted[0])*(i-j));
+            sorted[j] = idx[i] = k;
+        }
+        result = rb_ary_new_capa(n);
+        RARRAY_PTR_USE(result, ptr_result, {
+            for (i=0; i<n; i++) {
+                ptr_result[i] = RARRAY_AREF(ary, idx[i]);
+            }
+        });
     }
     else if (n <= memo_threshold / 2) {
-	long max_idx = 0;
-#undef RUBY_UNTYPED_DATA_WARNING
-#define RUBY_UNTYPED_DATA_WARNING 0
-	VALUE vmemo = Data_Wrap_Struct(0, 0, st_free_table, 0);
-	st_table *memo = st_init_numtable_with_size(n);
-	DATA_PTR(vmemo) = memo;
-	result = rb_ary_new_capa(n);
-	RARRAY_PTR_USE(result, ptr_result, {
-	    for (i=0; i<n; i++) {
-		long r = RAND_UPTO(len-i) + i;
-		ptr_result[i] = r;
-		if (r > max_idx) max_idx = r;
-	    }
-	    len = RARRAY_LEN(ary);
-	    if (len <= max_idx) n = 0;
-	    else if (n > len) n = len;
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr_ary, {
-		for (i=0; i<n; i++) {
-		    long j2 = j = ptr_result[i];
-		    long i2 = i;
-		    st_data_t value;
-		    if (st_lookup(memo, (st_data_t)i, &value)) i2 = (long)value;
-		    if (st_lookup(memo, (st_data_t)j, &value)) j2 = (long)value;
-		    st_insert(memo, (st_data_t)j, (st_data_t)i2);
-		    ptr_result[i] = ptr_ary[j2];
-		}
-	    });
-	});
-	DATA_PTR(vmemo) = 0;
-	st_free_table(memo);
+        long max_idx = 0;
+        VALUE vmemo = TypedData_Wrap_Struct(0, &ary_sample_memo_type, 0);
+        st_table *memo = st_init_numtable_with_size(n);
+        RTYPEDDATA_DATA(vmemo) = memo;
+        result = rb_ary_new_capa(n);
+        RARRAY_PTR_USE(result, ptr_result, {
+            for (i=0; i<n; i++) {
+                long r = RAND_UPTO(len-i) + i;
+                ptr_result[i] = r;
+                if (r > max_idx) max_idx = r;
+            }
+            len = RARRAY_LEN(ary);
+            if (len <= max_idx) n = 0;
+            else if (n > len) n = len;
+            RARRAY_PTR_USE(ary, ptr_ary, {
+                for (i=0; i<n; i++) {
+                    long j2 = j = ptr_result[i];
+                    long i2 = i;
+                    st_data_t value;
+                    if (st_lookup(memo, (st_data_t)i, &value)) i2 = (long)value;
+                    if (st_lookup(memo, (st_data_t)j, &value)) j2 = (long)value;
+                    st_insert(memo, (st_data_t)j, (st_data_t)i2);
+                    ptr_result[i] = ptr_ary[j2];
+                }
+            });
+        });
+        RTYPEDDATA_DATA(vmemo) = 0;
+        st_free_table(memo);
+        RB_GC_GUARD(vmemo);
     }
     else {
-	result = rb_ary_dup(ary);
-	RBASIC_CLEAR_CLASS(result);
-	RB_GC_GUARD(ary);
-	RARRAY_PTR_USE(result, ptr_result, {
-	    for (i=0; i<n; i++) {
-		j = RAND_UPTO(len-i) + i;
-		nv = ptr_result[j];
-		ptr_result[j] = ptr_result[i];
-		ptr_result[i] = nv;
-	    }
-	});
-	RBASIC_SET_CLASS_RAW(result, rb_cArray);
+        result = rb_ary_dup(ary);
+        RBASIC_CLEAR_CLASS(result);
+        RB_GC_GUARD(ary);
+        RARRAY_PTR_USE(result, ptr_result, {
+            for (i=0; i<n; i++) {
+                j = RAND_UPTO(len-i) + i;
+                nv = ptr_result[j];
+                ptr_result[j] = ptr_result[i];
+                ptr_result[i] = nv;
+            }
+        });
+        RBASIC_SET_CLASS_RAW(result, rb_cArray);
     }
     ARY_SET_LEN(result, n);
 
@@ -5542,15 +7004,27 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary)
 }
 
 static VALUE
+ary_sized_alloc(rb_execution_context_t *ec, VALUE self)
+{
+    return rb_ary_new2(RARRAY_LEN(self));
+}
+
+static VALUE
+ary_sample0(rb_execution_context_t *ec, VALUE ary)
+{
+    return ary_sample(ec, ary, rb_cRandom, Qfalse, Qfalse);
+}
+
+static VALUE
 rb_ary_cycle_size(VALUE self, VALUE args, VALUE eobj)
 {
     long mul;
     VALUE n = Qnil;
     if (args && (RARRAY_LEN(args) > 0)) {
-	n = RARRAY_AREF(args, 0);
+        n = RARRAY_AREF(args, 0);
     }
     if (RARRAY_LEN(self) == 0) return INT2FIX(0);
-    if (n == Qnil) return DBL2NUM(HUGE_VAL);
+    if (NIL_P(n)) return DBL2NUM(HUGE_VAL);
     mul = NUM2LONG(n);
     if (mul <= 0) return INT2FIX(0);
     n = LONG2FIX(mul);
@@ -5559,24 +7033,37 @@ rb_ary_cycle_size(VALUE self, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *     ary.cycle(n=nil) {|obj| block}    -> nil
- *     ary.cycle(n=nil)                  -> Enumerator
+ *    cycle(count = nil) {|element| ... } -> nil
+ *    cycle(count = nil) -> new_enumerator
  *
- *  Calls the given block for each element +n+ times or forever if +nil+ is
- *  given.
+ *  With a block given, may call the block, depending on the value of argument +count+;
+ *  +count+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects],
+ *  or +nil+.
  *
- *  Does nothing if a non-positive number is given or the array is empty.
+ *  When +count+ is positive,
+ *  calls the block with each element, then does so repeatedly,
+ *  until it has done so +count+ times; returns +nil+:
  *
- *  Returns +nil+ if the loop has finished without getting interrupted.
+ *    output = []
+ *    [0, 1].cycle(2) {|element| output.push(element) } # => nil
+ *    output # => [0, 1, 0, 1]
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  When +count+ is zero or negative, does not call the block:
  *
- *     a = ["a", "b", "c"]
- *     a.cycle {|x| puts x}       # print, a, b, c, a, b, c,.. forever.
- *     a.cycle(2) {|x| puts x}    # print, a, b, c, a, b, c.
+ *    [0, 1].cycle(0) {|element| fail 'Cannot happen' }  # => nil
+ *    [0, 1].cycle(-1) {|element| fail 'Cannot happen' } # => nil
  *
+ *  When +count+ is +nil+, cycles forever:
+ *
+ *    # Prints 0 and 1 forever.
+ *    [0, 1].cycle {|element| puts element }
+ *    [0, 1].cycle(nil) {|element| puts element }
+ *
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
-
 static VALUE
 rb_ary_cycle(int argc, VALUE *argv, VALUE ary)
 {
@@ -5601,9 +7088,6 @@ rb_ary_cycle(int argc, VALUE *argv, VALUE ary)
     return Qnil;
 }
 
-#define tmpary(n) rb_ary_tmp_new(n)
-#define tmpary_discard(a) (ary_discard(a), RBASIC_SET_CLASS_RAW(a, rb_cArray))
-
 /*
  * Build a ruby array of the corresponding values and yield it to the
  * associated block.
@@ -5639,52 +7123,52 @@ permute0(const long n, const long r, long *const p, char *const used, const VALU
     long i = 0, index = 0;
 
     for (;;) {
-	const char *const unused = memchr(&used[i], 0, n-i);
-	if (!unused) {
-	    if (!index) break;
-	    i = p[--index];                /* pop index */
-	    used[i++] = 0;                 /* index unused */
-	}
-	else {
-	    i = unused - used;
-	    p[index] = i;
-	    used[i] = 1;                   /* mark index used */
-	    ++index;
-	    if (index < r-1) {             /* if not done yet */
-		p[index] = i = 0;
-		continue;
-	    }
-	    for (i = 0; i < n; ++i) {
-		if (used[i]) continue;
-		p[index] = i;
-		if (!yield_indexed_values(values, r, p)) {
-		    rb_raise(rb_eRuntimeError, "permute reentered");
-		}
-	    }
-	    i = p[--index];                /* pop index */
-	    used[i] = 0;                   /* index unused */
-	    p[index] = ++i;
-	}
+        const char *const unused = memchr(&used[i], 0, n-i);
+        if (!unused) {
+            if (!index) break;
+            i = p[--index];                /* pop index */
+            used[i++] = 0;                 /* index unused */
+        }
+        else {
+            i = unused - used;
+            p[index] = i;
+            used[i] = 1;                   /* mark index used */
+            ++index;
+            if (index < r-1) {             /* if not done yet */
+                p[index] = i = 0;
+                continue;
+            }
+            for (i = 0; i < n; ++i) {
+                if (used[i]) continue;
+                p[index] = i;
+                if (!yield_indexed_values(values, r, p)) {
+                    rb_raise(rb_eRuntimeError, "permute reentered");
+                }
+            }
+            i = p[--index];                /* pop index */
+            used[i] = 0;                   /* index unused */
+            p[index] = ++i;
+        }
     }
 }
 
 /*
  * Returns the product of from, from-1, ..., from - how_many + 1.
- * http://en.wikipedia.org/wiki/Pochhammer_symbol
+ * https://en.wikipedia.org/wiki/Pochhammer_symbol
  */
 static VALUE
 descending_factorial(long from, long how_many)
 {
     VALUE cnt;
     if (how_many > 0) {
-	cnt = LONG2FIX(from);
-	while (--how_many > 0) {
-	    long v = --from;
-	    cnt = rb_int_mul(cnt, LONG2FIX(v));
-	}
+        cnt = LONG2FIX(from);
+        while (--how_many > 0) {
+            long v = --from;
+            cnt = rb_int_mul(cnt, LONG2FIX(v));
+        }
     }
     else {
-	cnt = LONG2FIX(how_many == 0);
+        cnt = LONG2FIX(how_many == 0);
     }
     return cnt;
 }
@@ -5695,18 +7179,18 @@ binomial_coefficient(long comb, long size)
     VALUE r;
     long i;
     if (comb > size-comb) {
-	comb = size-comb;
+        comb = size-comb;
     }
     if (comb < 0) {
-	return LONG2FIX(0);
+        return LONG2FIX(0);
     }
     else if (comb == 0) {
-	return LONG2FIX(1);
+        return LONG2FIX(1);
     }
     r = LONG2FIX(size);
     for (i = 1; i < comb; ++i) {
-	r = rb_int_mul(r, LONG2FIX(size - i));
-	r = rb_int_idiv(r, LONG2FIX(i + 1));
+        r = rb_int_mul(r, LONG2FIX(size - i));
+        r = rb_int_idiv(r, LONG2FIX(i + 1));
     }
     return r;
 }
@@ -5722,30 +7206,44 @@ rb_ary_permutation_size(VALUE ary, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *     ary.permutation {|p| block}            -> ary
- *     ary.permutation                        -> Enumerator
- *     ary.permutation(n) {|p| block}         -> ary
- *     ary.permutation(n)                     -> Enumerator
+ *    permutation(count = self.size) {|permutation| ... } -> self
+ *    permutation(count = self.size) -> new_enumerator
+ *
+ *  Iterates over permutations of the elements of +self+;
+ *  the order of permutations is indeterminate.
+ *
+ *  With a block and an in-range positive integer argument +count+ (<tt>0 < count <= self.size</tt>) given,
+ *  calls the block with each permutation of +self+ of size +count+;
+ *  returns +self+:
+ *
+ *    a = [0, 1, 2]
+ *    perms = []
+ *    a.permutation(1) {|perm| perms.push(perm) }
+ *    perms # => [[0], [1], [2]]
+ *
+ *    perms = []
+ *    a.permutation(2) {|perm| perms.push(perm) }
+ *    perms # => [[0, 1], [0, 2], [1, 0], [1, 2], [2, 0], [2, 1]]
+ *
+ *    perms = []
+ *    a.permutation(3) {|perm| perms.push(perm) }
+ *    perms # => [[0, 1, 2], [0, 2, 1], [1, 0, 2], [1, 2, 0], [2, 0, 1], [2, 1, 0]]
  *
- * When invoked with a block, yield all permutations of length +n+ of the
- * elements of the array, then return the array itself.
+ *  When +count+ is zero, calls the block once with a new empty array:
  *
- * If +n+ is not specified, yield all permutations of all elements.
+ *    perms = []
+ *    a.permutation(0) {|perm| perms.push(perm) }
+ *    perms # => [[]]
  *
- * The implementation makes no guarantees about the order in which the
- * permutations are yielded.
+ *  When +count+ is out of range (negative or larger than <tt>self.size</tt>),
+ *  does not call the block:
  *
- * If no block is given, an Enumerator is returned instead.
+ *    a.permutation(-1) {|permutation| fail 'Cannot happen' }
+ *    a.permutation(4) {|permutation| fail 'Cannot happen' }
  *
- * Examples:
+ *  With no block given, returns a new Enumerator.
  *
- *   a = [1, 2, 3]
- *   a.permutation.to_a    #=> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
- *   a.permutation(1).to_a #=> [[1],[2],[3]]
- *   a.permutation(2).to_a #=> [[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]]
- *   a.permutation(3).to_a #=> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
- *   a.permutation(0).to_a #=> [[]] # one permutation of length 0
- *   a.permutation(4).to_a #=> []   # no permutations of length 4
+ *  Related: {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -5760,28 +7258,28 @@ rb_ary_permutation(int argc, VALUE *argv, VALUE ary)
         r = NUM2LONG(argv[0]);            /* Permutation size from argument */
 
     if (r < 0 || n < r) {
-	/* no permutations: yield nothing */
+        /* no permutations: yield nothing */
     }
     else if (r == 0) { /* exactly one permutation: the zero-length array */
-	rb_yield(rb_ary_new2(0));
+        rb_yield(rb_ary_new2(0));
     }
     else if (r == 1) { /* this is a special, easy case */
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+            rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+        }
     }
     else {             /* this is the general case */
-	volatile VALUE t0;
-	long *p = ALLOCV_N(long, t0, r+roomof(n, sizeof(long)));
-	char *used = (char*)(p + r);
-	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
-	RBASIC_CLEAR_CLASS(ary0);
+        volatile VALUE t0;
+        long *p = ALLOCV_N(long, t0, r+roomof(n, sizeof(long)));
+        char *used = (char*)(p + r);
+        VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+        RBASIC_CLEAR_CLASS(ary0);
 
-	MEMZERO(used, char, n); /* initialize array */
+        MEMZERO(used, char, n); /* initialize array */
 
-	permute0(n, r, p, used, ary0); /* compute and yield permutations */
-	ALLOCV_END(t0);
-	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+        permute0(n, r, p, used, ary0); /* compute and yield permutations */
+        ALLOCV_END(t0);
+        RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
     }
     return ary;
 }
@@ -5794,16 +7292,16 @@ combinate0(const long len, const long n, long *const stack, const VALUE values)
     MEMZERO(stack+1, long, n);
     stack[0] = -1;
     for (;;) {
-	for (lev++; lev < n; lev++) {
-	    stack[lev+1] = stack[lev]+1;
-	}
-	if (!yield_indexed_values(values, n, stack+1)) {
-	    rb_raise(rb_eRuntimeError, "combination reentered");
-	}
-	do {
-	    if (lev == 0) return;
-	    stack[lev--]++;
-	} while (stack[lev+1]+n == len+lev+1);
+        for (lev++; lev < n; lev++) {
+            stack[lev+1] = stack[lev]+1;
+        }
+        if (!yield_indexed_values(values, n, stack+1)) {
+            rb_raise(rb_eRuntimeError, "combination reentered");
+        }
+        do {
+            if (lev == 0) return;
+            stack[lev--]++;
+        } while (stack[lev+1]+n == len+lev+1);
     }
 }
 
@@ -5818,27 +7316,46 @@ rb_ary_combination_size(VALUE ary, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *     ary.combination(n) {|c| block}      -> ary
- *     ary.combination(n)                  -> Enumerator
+ *    combination(count) {|element| ... } -> self
+ *    combination(count) -> new_enumerator
+ *
+ *  When a block and a positive
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]
+ *  argument +count+ (<tt>0 < count <= self.size</tt>)
+ *  are given, calls the block with each combination of +self+ of size +count+;
+ *  returns +self+:
+ *
+ *    a = %w[a b c]                                   # => ["a", "b", "c"]
+ *    a.combination(2) {|combination| p combination } # => ["a", "b", "c"]
+ *
+ *  Output:
  *
- * When invoked with a block, yields all combinations of length +n+ of elements
- * from the array and then returns the array itself.
+ *    ["a", "b"]
+ *    ["a", "c"]
+ *    ["b", "c"]
  *
- * The implementation makes no guarantees about the order in which the
- * combinations are yielded.
+ *  The order of the yielded combinations is not guaranteed.
  *
- * If no block is given, an Enumerator is returned instead.
+ *  When +count+ is zero, calls the block once with a new empty array:
  *
- * Examples:
+ *    a.combination(0) {|combination| p combination }
+ *    [].combination(0) {|combination| p combination }
  *
- *     a = [1, 2, 3, 4]
- *     a.combination(1).to_a  #=> [[1],[2],[3],[4]]
- *     a.combination(2).to_a  #=> [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]
- *     a.combination(3).to_a  #=> [[1,2,3],[1,2,4],[1,3,4],[2,3,4]]
- *     a.combination(4).to_a  #=> [[1,2,3,4]]
- *     a.combination(0).to_a  #=> [[]] # one combination of length 0
- *     a.combination(5).to_a  #=> []   # no combinations of length 5
+ *  Output:
  *
+ *    []
+ *    []
+ *
+ *  When +count+ is negative or larger than +self.size+ and +self+ is non-empty,
+ *  does not call the block:
+ *
+ *    a.combination(-1) {|combination| fail 'Cannot happen' } # => ["a", "b", "c"]
+ *    a.combination(4)  {|combination| fail 'Cannot happen' } # => ["a", "b", "c"]
+ *
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: Array#permutation;
+ *  see also {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -5850,25 +7367,25 @@ rb_ary_combination(VALUE ary, VALUE num)
     RETURN_SIZED_ENUMERATOR(ary, 1, &num, rb_ary_combination_size);
     len = RARRAY_LEN(ary);
     if (n < 0 || len < n) {
-	/* yield nothing */
+        /* yield nothing */
     }
     else if (n == 0) {
-	rb_yield(rb_ary_new2(0));
+        rb_yield(rb_ary_new2(0));
     }
     else if (n == 1) {
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+            rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+        }
     }
     else {
-	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
-	volatile VALUE t0;
-	long *stack = ALLOCV_N(long, t0, n+1);
+        VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+        volatile VALUE t0;
+        long *stack = ALLOCV_N(long, t0, n+1);
 
-	RBASIC_CLEAR_CLASS(ary0);
-	combinate0(len, n, stack, ary0);
-	ALLOCV_END(t0);
-	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+        RBASIC_CLEAR_CLASS(ary0);
+        combinate0(len, n, stack, ary0);
+        ALLOCV_END(t0);
+        RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
     }
     return ary;
 }
@@ -5892,19 +7409,19 @@ rpermute0(const long n, const long r, long *const p, const VALUE values)
 
     p[index] = i;
     for (;;) {
-	if (++index < r-1) {
-	    p[index] = i = 0;
-	    continue;
-	}
-	for (i = 0; i < n; ++i) {
-	    p[index] = i;
-	    if (!yield_indexed_values(values, r, p)) {
-		rb_raise(rb_eRuntimeError, "repeated permute reentered");
-	    }
-	}
-	do {
-	    if (index <= 0) return;
-	} while ((i = ++p[--index]) >= n);
+        if (++index < r-1) {
+            p[index] = i = 0;
+            continue;
+        }
+        for (i = 0; i < n; ++i) {
+            p[index] = i;
+            if (!yield_indexed_values(values, r, p)) {
+                rb_raise(rb_eRuntimeError, "repeated permute reentered");
+            }
+        }
+        do {
+            if (index <= 0) return;
+        } while ((i = ++p[--index]) >= n);
     }
 }
 
@@ -5915,37 +7432,52 @@ rb_ary_repeated_permutation_size(VALUE ary, VALUE args, VALUE eobj)
     long k = NUM2LONG(RARRAY_AREF(args, 0));
 
     if (k < 0) {
-	return LONG2FIX(0);
+        return LONG2FIX(0);
     }
     if (n <= 0) {
-	return LONG2FIX(!k);
+        return LONG2FIX(!k);
     }
     return rb_int_positive_pow(n, (unsigned long)k);
 }
 
 /*
  *  call-seq:
- *     ary.repeated_permutation(n) {|p| block}   -> ary
- *     ary.repeated_permutation(n)               -> Enumerator
+ *    repeated_permutation(size) {|permutation| ... } -> self
+ *    repeated_permutation(size) -> new_enumerator
+ *
+ *  With a block given, calls the block with each repeated permutation of length +size+
+ *  of the elements of +self+;
+ *  each permutation is an array;
+ *  returns +self+. The order of the permutations is indeterminate.
+ *
+ *  If a positive integer argument +size+ is given,
+ *  calls the block with each +size+-tuple repeated permutation of the elements of +self+.
+ *  The number of permutations is <tt>self.size**size</tt>.
+ *
+ *  Examples:
+ *
+ *  - +size+ is 1:
  *
- * When invoked with a block, yield all repeated permutations of length +n+ of
- * the elements of the array, then return the array itself.
+ *      p = []
+ *      [0, 1, 2].repeated_permutation(1) {|permutation| p.push(permutation) }
+ *      p # => [[0], [1], [2]]
  *
- * The implementation makes no guarantees about the order in which the repeated
- * permutations are yielded.
+ *  - +size+ is 2:
  *
- * If no block is given, an Enumerator is returned instead.
+ *      p = []
+ *      [0, 1, 2].repeated_permutation(2) {|permutation| p.push(permutation) }
+ *      p # => [[0, 0], [0, 1], [0, 2], [1, 0], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]]
  *
- * Examples:
+ *  If +size+ is zero, calls the block once with an empty array.
  *
- *     a = [1, 2]
- *     a.repeated_permutation(1).to_a  #=> [[1], [2]]
- *     a.repeated_permutation(2).to_a  #=> [[1,1],[1,2],[2,1],[2,2]]
- *     a.repeated_permutation(3).to_a  #=> [[1,1,1],[1,1,2],[1,2,1],[1,2,2],
- *                                     #    [2,1,1],[2,1,2],[2,2,1],[2,2,2]]
- *     a.repeated_permutation(0).to_a  #=> [[]] # one permutation of length 0
+ *  If +size+ is negative, does not call the block:
+ *
+ *    [0, 1, 2].repeated_permutation(-1) {|permutation| fail 'Cannot happen' }
+ *
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
-
 static VALUE
 rb_ary_repeated_permutation(VALUE ary, VALUE num)
 {
@@ -5956,25 +7488,25 @@ rb_ary_repeated_permutation(VALUE ary, VALUE num)
     r = NUM2LONG(num);                    /* Permutation size from argument */
 
     if (r < 0) {
-	/* no permutations: yield nothing */
+        /* no permutations: yield nothing */
     }
     else if (r == 0) { /* exactly one permutation: the zero-length array */
-	rb_yield(rb_ary_new2(0));
+        rb_yield(rb_ary_new2(0));
     }
     else if (r == 1) { /* this is a special, easy case */
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+            rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+        }
     }
     else {             /* this is the general case */
-	volatile VALUE t0;
-	long *p = ALLOCV_N(long, t0, r);
-	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
-	RBASIC_CLEAR_CLASS(ary0);
+        volatile VALUE t0;
+        long *p = ALLOCV_N(long, t0, r);
+        VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+        RBASIC_CLEAR_CLASS(ary0);
 
-	rpermute0(n, r, p, ary0); /* compute and yield repeated permutations */
-	ALLOCV_END(t0);
-	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+        rpermute0(n, r, p, ary0); /* compute and yield repeated permutations */
+        ALLOCV_END(t0);
+        RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
     }
     return ary;
 }
@@ -5986,19 +7518,19 @@ rcombinate0(const long n, const long r, long *const p, const long rest, const VA
 
     p[index] = i;
     for (;;) {
-	if (++index < r-1) {
-	    p[index] = i;
-	    continue;
-	}
-	for (; i < n; ++i) {
-	    p[index] = i;
-	    if (!yield_indexed_values(values, r, p)) {
-		rb_raise(rb_eRuntimeError, "repeated combination reentered");
-	    }
-	}
-	do {
-	    if (index <= 0) return;
-	} while ((i = ++p[--index]) >= n);
+        if (++index < r-1) {
+            p[index] = i;
+            continue;
+        }
+        for (; i < n; ++i) {
+            p[index] = i;
+            if (!yield_indexed_values(values, r, p)) {
+                rb_raise(rb_eRuntimeError, "repeated combination reentered");
+            }
+        }
+        do {
+            if (index <= 0) return;
+        } while ((i = ++p[--index]) >= n);
     }
 }
 
@@ -6008,36 +7540,48 @@ rb_ary_repeated_combination_size(VALUE ary, VALUE args, VALUE eobj)
     long n = RARRAY_LEN(ary);
     long k = NUM2LONG(RARRAY_AREF(args, 0));
     if (k == 0) {
-	return LONG2FIX(1);
+        return LONG2FIX(1);
     }
     return binomial_coefficient(k, n + k - 1);
 }
 
 /*
  *  call-seq:
- *     ary.repeated_combination(n) {|c| block}   -> ary
- *     ary.repeated_combination(n)               -> Enumerator
+ *    repeated_combination(size) {|combination| ... } -> self
+ *    repeated_combination(size) -> new_enumerator
+ *
+ *  With a block given, calls the block with each repeated combination of length +size+
+ *  of the elements of +self+;
+ *  each combination is an array;
+ *  returns +self+. The order of the combinations is indeterminate.
+ *
+ *  If a positive integer argument +size+ is given,
+ *  calls the block with each +size+-tuple repeated combination of the elements of +self+.
+ *  The number of combinations is <tt>(size+1)(size+2)/2</tt>.
+ *
+ *  Examples:
+ *
+ *  - +size+ is 1:
  *
- * When invoked with a block, yields all repeated combinations of length +n+ of
- * elements from the array and then returns the array itself.
+ *      c = []
+ *      [0, 1, 2].repeated_combination(1) {|combination| c.push(combination) }
+ *      c # => [[0], [1], [2]]
  *
- * The implementation makes no guarantees about the order in which the repeated
- * combinations are yielded.
+ *  - +size+ is 2:
  *
- * If no block is given, an Enumerator is returned instead.
+ *      c = []
+ *      [0, 1, 2].repeated_combination(2) {|combination| c.push(combination) }
+ *      c # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]
  *
- * Examples:
+ *  If +size+ is zero, calls the block once with an empty array.
  *
- *   a = [1, 2, 3]
- *   a.repeated_combination(1).to_a  #=> [[1], [2], [3]]
- *   a.repeated_combination(2).to_a  #=> [[1,1],[1,2],[1,3],[2,2],[2,3],[3,3]]
- *   a.repeated_combination(3).to_a  #=> [[1,1,1],[1,1,2],[1,1,3],[1,2,2],[1,2,3],
- *                                   #    [1,3,3],[2,2,2],[2,2,3],[2,3,3],[3,3,3]]
- *   a.repeated_combination(4).to_a  #=> [[1,1,1,1],[1,1,1,2],[1,1,1,3],[1,1,2,2],[1,1,2,3],
- *                                   #    [1,1,3,3],[1,2,2,2],[1,2,2,3],[1,2,3,3],[1,3,3,3],
- *                                   #    [2,2,2,2],[2,2,2,3],[2,2,3,3],[2,3,3,3],[3,3,3,3]]
- *   a.repeated_combination(0).to_a  #=> [[]] # one combination of length 0
+ *  If +size+ is negative, does not call the block:
  *
+ *    [0, 1, 2].repeated_combination(-1) {|combination| fail 'Cannot happen' }
+ *
+ *  With no block given, returns a new Enumerator.
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -6049,58 +7593,90 @@ rb_ary_repeated_combination(VALUE ary, VALUE num)
     RETURN_SIZED_ENUMERATOR(ary, 1, &num, rb_ary_repeated_combination_size);   /* Return enumerator if no block */
     len = RARRAY_LEN(ary);
     if (n < 0) {
-	/* yield nothing */
+        /* yield nothing */
     }
     else if (n == 0) {
-	rb_yield(rb_ary_new2(0));
+        rb_yield(rb_ary_new2(0));
     }
     else if (n == 1) {
-	for (i = 0; i < RARRAY_LEN(ary); i++) {
-	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
-	}
+        for (i = 0; i < RARRAY_LEN(ary); i++) {
+            rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+        }
     }
     else if (len == 0) {
-	/* yield nothing */
+        /* yield nothing */
     }
     else {
-	volatile VALUE t0;
-	long *p = ALLOCV_N(long, t0, n);
-	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
-	RBASIC_CLEAR_CLASS(ary0);
+        volatile VALUE t0;
+        long *p = ALLOCV_N(long, t0, n);
+        VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+        RBASIC_CLEAR_CLASS(ary0);
 
-	rcombinate0(len, n, p, n, ary0); /* compute and yield repeated combinations */
-	ALLOCV_END(t0);
-	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+        rcombinate0(len, n, p, n, ary0); /* compute and yield repeated combinations */
+        ALLOCV_END(t0);
+        RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
     }
     return ary;
 }
 
 /*
  *  call-seq:
- *     ary.product(other_ary, ...)                -> new_ary
- *     ary.product(other_ary, ...) {|p| block}    -> ary
+ *    product(*other_arrays) -> new_array
+ *    product(*other_arrays) {|combination| ... } -> self
+ *
+ *  Computes all combinations of elements from all the arrays,
+ *  including both +self+ and +other_arrays+:
+ *
+ *  - The number of combinations is the product of the sizes of all the arrays,
+ *    including both +self+ and +other_arrays+.
+ *  - The order of the returned combinations is indeterminate.
+ *
+ *  With no block given, returns the combinations as an array of arrays:
+ *
+ *    p = [0, 1].product([2, 3])
+ *    # => [[0, 2], [0, 3], [1, 2], [1, 3]]
+ *    p.size # => 4
+ *    p = [0, 1].product([2, 3], [4, 5])
+ *    # => [[0, 2, 4], [0, 2, 5], [0, 3, 4], [0, 3, 5], [1, 2, 4], [1, 2, 5], [1, 3, 4], [1, 3,...
+ *    p.size # => 8
+ *
+ *  If +self+ or any argument is empty, returns an empty array:
+ *
+ *    [].product([2, 3], [4, 5]) # => []
+ *    [0, 1].product([2, 3], []) # => []
+ *
+ *  If no argument is given, returns an array of 1-element arrays,
+ *  each containing an element of +self+:
+ *
+ *    a.product # => [[0], [1], [2]]
  *
- *  Returns an array of all combinations of elements from all arrays.
+ *  With a block given, calls the block with each combination; returns +self+:
  *
- *  The length of the returned array is the product of the length of +self+ and
- *  the argument arrays.
+ *    p = []
+ *    [0, 1].product([2, 3]) {|combination| p.push(combination) }
+ *    p # => [[0, 2], [0, 3], [1, 2], [1, 3]]
  *
- *  If given a block, #product will yield all combinations and return +self+
- *  instead.
+ *  If +self+ or any argument is empty, does not call the block:
  *
- *     [1,2,3].product([4,5])     #=> [[1,4],[1,5],[2,4],[2,5],[3,4],[3,5]]
- *     [1,2].product([1,2])       #=> [[1,1],[1,2],[2,1],[2,2]]
- *     [1,2].product([3,4],[5,6]) #=> [[1,3,5],[1,3,6],[1,4,5],[1,4,6],
- *                                #     [2,3,5],[2,3,6],[2,4,5],[2,4,6]]
- *     [1,2].product()            #=> [[1],[2]]
- *     [1,2].product([])          #=> []
+ *    [].product([2, 3], [4, 5]) {|combination| fail 'Cannot happen' }
+ *    # => []
+ *    [0, 1].product([2, 3], []) {|combination| fail 'Cannot happen' }
+ *    # => [0, 1]
+ *
+ *  If no argument is given, calls the block with each element of +self+ as a 1-element array:
+ *
+ *    p = []
+ *    [0, 1].product {|combination| p.push(combination) }
+ *    p # => [[0], [1]]
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
 rb_ary_product(int argc, VALUE *argv, VALUE ary)
 {
     int n = argc+1;    /* How many arrays we're operating on */
-    volatile VALUE t0 = tmpary(n);
+    volatile VALUE t0 = rb_ary_hidden_new(n);
     volatile VALUE t1 = Qundef;
     VALUE *arrays = RARRAY_PTR(t0); /* The arrays we're computing the product of */
     int *counters = ALLOCV_N(int, t1, n); /* The current position in each one */
@@ -6121,64 +7697,64 @@ rb_ary_product(int argc, VALUE *argv, VALUE ary)
 
     /* Otherwise, allocate and fill in an array of results */
     if (rb_block_given_p()) {
-	/* Make defensive copies of arrays; exit if any is empty */
-	for (i = 0; i < n; i++) {
-	    if (RARRAY_LEN(arrays[i]) == 0) goto done;
-	    arrays[i] = ary_make_shared_copy(arrays[i]);
-	}
+        /* Make defensive copies of arrays; exit if any is empty */
+        for (i = 0; i < n; i++) {
+            if (RARRAY_LEN(arrays[i]) == 0) goto done;
+            arrays[i] = ary_make_shared_copy(arrays[i]);
+        }
     }
     else {
-	/* Compute the length of the result array; return [] if any is empty */
-	for (i = 0; i < n; i++) {
-	    long k = RARRAY_LEN(arrays[i]);
-	    if (k == 0) {
-		result = rb_ary_new2(0);
-		goto done;
-	    }
+        /* Compute the length of the result array; return [] if any is empty */
+        for (i = 0; i < n; i++) {
+            long k = RARRAY_LEN(arrays[i]);
+            if (k == 0) {
+                result = rb_ary_new2(0);
+                goto done;
+            }
             if (MUL_OVERFLOW_LONG_P(resultlen, k))
-		rb_raise(rb_eRangeError, "too big to product");
-	    resultlen *= k;
-	}
-	result = rb_ary_new2(resultlen);
+                rb_raise(rb_eRangeError, "too big to product");
+            resultlen *= k;
+        }
+        result = rb_ary_new2(resultlen);
     }
     for (;;) {
-	int m;
-	/* fill in one subarray */
-	VALUE subarray = rb_ary_new2(n);
-	for (j = 0; j < n; j++) {
-	    rb_ary_push(subarray, rb_ary_entry(arrays[j], counters[j]));
-	}
-
-	/* put it on the result array */
-	if (NIL_P(result)) {
-	    FL_SET(t0, FL_USER5);
-	    rb_yield(subarray);
-	    if (! FL_TEST(t0, FL_USER5)) {
-		rb_raise(rb_eRuntimeError, "product reentered");
-	    }
-	    else {
-		FL_UNSET(t0, FL_USER5);
-	    }
-	}
-	else {
-	    rb_ary_push(result, subarray);
-	}
-
-	/*
-	 * Increment the last counter.  If it overflows, reset to 0
-	 * and increment the one before it.
-	 */
-	m = n-1;
-	counters[m]++;
-	while (counters[m] == RARRAY_LEN(arrays[m])) {
-	    counters[m] = 0;
-	    /* If the first counter overflows, we are done */
-	    if (--m < 0) goto done;
-	    counters[m]++;
-	}
+        int m;
+        /* fill in one subarray */
+        VALUE subarray = rb_ary_new2(n);
+        for (j = 0; j < n; j++) {
+            rb_ary_push(subarray, rb_ary_entry(arrays[j], counters[j]));
+        }
+
+        /* put it on the result array */
+        if (NIL_P(result)) {
+            FL_SET(t0, RARRAY_SHARED_ROOT_FLAG);
+            rb_yield(subarray);
+            if (!FL_TEST(t0, RARRAY_SHARED_ROOT_FLAG)) {
+                rb_raise(rb_eRuntimeError, "product reentered");
+            }
+            else {
+                FL_UNSET(t0, RARRAY_SHARED_ROOT_FLAG);
+            }
+        }
+        else {
+            rb_ary_push(result, subarray);
+        }
+
+        /*
+         * Increment the last counter.  If it overflows, reset to 0
+         * and increment the one before it.
+         */
+        m = n-1;
+        counters[m]++;
+        while (counters[m] == RARRAY_LEN(arrays[m])) {
+            counters[m] = 0;
+            /* If the first counter overflows, we are done */
+            if (--m < 0) goto done;
+            counters[m]++;
+        }
     }
+
 done:
-    tmpary_discard(t0);
     ALLOCV_END(t1);
 
     return NIL_P(result) ? ary : result;
@@ -6186,17 +7762,20 @@ done:
 
 /*
  *  call-seq:
- *     ary.take(n)               -> new_ary
- *
- *  Returns first +n+ elements from the array.
- *
- *  If a negative number is given, raises an ArgumentError.
+ *    take(count) -> new_array
  *
- *  See also Array#drop
+ *  Returns a new array containing the first +count+ element of +self+
+ *  (as available);
+ *  +count+ must be a non-negative numeric;
+ *  does not modify +self+:
  *
- *     a = [1, 2, 3, 4, 5, 0]
- *     a.take(3)             #=> [1, 2, 3]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.take(2)   # => ["a", "b"]
+ *    a.take(2.1) # => ["a", "b"]
+ *    a.take(50)  # => ["a", "b", "c", "d"]
+ *    a.take(0)   # => []
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -6204,26 +7783,30 @@ rb_ary_take(VALUE obj, VALUE n)
 {
     long len = NUM2LONG(n);
     if (len < 0) {
-	rb_raise(rb_eArgError, "attempt to take negative size");
+        rb_raise(rb_eArgError, "attempt to take negative size");
     }
     return rb_ary_subseq(obj, 0, len);
 }
 
 /*
  *  call-seq:
- *     ary.take_while {|obj| block}    -> new_ary
- *     ary.take_while                  -> Enumerator
+ *    take_while {|element| ... } -> new_array
+ *    take_while -> new_enumerator
  *
- *  Passes elements to the block until the block returns +nil+ or +false+, then
- *  stops iterating and returns an array of all prior elements.
+ *  With a block given, calls the block with each successive element of +self+;
+ *  stops iterating if the block returns +false+ or +nil+;
+ *  returns a new array containing those elements for which the block returned a truthy value:
  *
- *  If no block is given, an Enumerator is returned instead.
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.take_while {|element| element < 3 } # => [0, 1, 2]
+ *    a.take_while {|element| true }        # => [0, 1, 2, 3, 4, 5]
+ *    a.take_while {|element| false }       # => []
  *
- *  See also Array#drop_while
+ *  With no block given, returns a new Enumerator.
  *
- *     a = [1, 2, 3, 4, 5, 0]
- *     a.take_while {|i| i < 3}    #=> [1, 2]
+ *  Does not modify +self+.
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -6233,25 +7816,28 @@ rb_ary_take_while(VALUE ary)
 
     RETURN_ENUMERATOR(ary, 0, 0);
     for (i = 0; i < RARRAY_LEN(ary); i++) {
-	if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) break;
+        if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) break;
     }
     return rb_ary_take(ary, LONG2FIX(i));
 }
 
 /*
  *  call-seq:
- *     ary.drop(n)               -> new_ary
+ *    drop(count) -> new_array
  *
- *  Drops first +n+ elements from +ary+ and returns the rest of the elements in
- *  an array.
+ *  Returns a new array containing all but the first +count+ element of +self+,
+ *  where +count+ is a non-negative integer;
+ *  does not modify +self+.
  *
- *  If a negative number is given, raises an ArgumentError.
+ *  Examples:
  *
- *  See also Array#take
- *
- *     a = [1, 2, 3, 4, 5, 0]
- *     a.drop(3)             #=> [4, 5, 0]
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.drop(0) # => [0, 1, 2, 3, 4, 5]
+ *    a.drop(1) # => [1, 2, 3, 4, 5]
+ *    a.drop(2) # => [2, 3, 4, 5]
+ *    a.drop(9) # => []
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -6260,30 +7846,30 @@ rb_ary_drop(VALUE ary, VALUE n)
     VALUE result;
     long pos = NUM2LONG(n);
     if (pos < 0) {
-	rb_raise(rb_eArgError, "attempt to drop negative size");
+        rb_raise(rb_eArgError, "attempt to drop negative size");
     }
 
     result = rb_ary_subseq(ary, pos, RARRAY_LEN(ary));
-    if (result == Qnil) result = rb_ary_new();
+    if (NIL_P(result)) result = rb_ary_new();
     return result;
 }
 
 /*
  *  call-seq:
- *     ary.drop_while {|obj| block}     -> new_ary
- *     ary.drop_while                  -> Enumerator
- *
- *  Drops elements up to, but not including, the first element for which the
- *  block returns +nil+ or +false+ and returns an array containing the
- *  remaining elements.
+ *    drop_while {|element| ... } -> new_array
+ *    drop_while -> new_enumerator
  *
- *  If no block is given, an Enumerator is returned instead.
+ *  With a block given, calls the block with each successive element of +self+;
+ *  stops if the block returns +false+ or +nil+;
+ *  returns a new array _omitting_ those elements for which the block returned a truthy value;
+ *  does not modify +self+:
  *
- *  See also Array#take_while
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.drop_while {|element| element < 3 } # => [3, 4, 5]
  *
- *     a = [1, 2, 3, 4, 5, 0]
- *     a.drop_while {|i| i < 3 }   #=> [3, 4, 5, 0]
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -6293,17 +7879,48 @@ rb_ary_drop_while(VALUE ary)
 
     RETURN_ENUMERATOR(ary, 0, 0);
     for (i = 0; i < RARRAY_LEN(ary); i++) {
-	if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) break;
+        if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) break;
     }
     return rb_ary_drop(ary, LONG2FIX(i));
 }
 
 /*
  *  call-seq:
- *     ary.any? [{|obj| block}  ]   -> true or false
- *     ary.any?(pattern)            -> true or false
+ *    any? -> true or false
+ *    any?(object) -> true or false
+ *    any? {|element| ... } -> true or false
+ *
+ *  Returns whether for any element of +self+, a given criterion is satisfied.
  *
- *  See also Enumerable#any?
+ *  With no block and no argument, returns whether any element of +self+ is truthy:
+ *
+ *    [nil, false, []].any? # => true  # Array object is truthy.
+ *    [nil, false, {}].any? # => true  # Hash object is truthy.
+ *    [nil, false, ''].any? # => true  # String object is truthy.
+ *    [nil, false].any?     # => false # Nil and false are not truthy.
+ *
+ *  With argument +object+ given,
+ *  returns whether <tt>object === ele</tt> for any element +ele+ in +self+:
+ *
+ *    [nil, false, 0].any?(0)          # => true
+ *    [nil, false, 1].any?(0)          # => false
+ *    [nil, false, 'food'].any?(/foo/) # => true
+ *    [nil, false, 'food'].any?(/bar/) # => false
+ *
+ *  With a block given,
+ *  calls the block with each element in +self+;
+ *  returns whether the block returns any truthy value:
+ *
+ *    [0, 1, 2].any? {|ele| ele < 1 } # => true
+ *    [0, 1, 2].any? {|ele| ele < 0 } # => false
+ *
+ *  With both a block and argument +object+ given,
+ *  ignores the block and uses +object+ as above.
+ *
+ *  <b>Special case</b>: returns +false+ if +self+ is empty
+ *  (regardless of any given argument or block).
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -6317,9 +7934,9 @@ rb_ary_any_p(int argc, VALUE *argv, VALUE ary)
         if (rb_block_given_p()) {
             rb_warn("given block not used");
         }
-	for (i = 0; i < RARRAY_LEN(ary); ++i) {
-	    if (RTEST(rb_funcall(argv[0], idEqq, 1, RARRAY_AREF(ary, i)))) return Qtrue;
-	}
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (RTEST(rb_funcall(argv[0], idEqq, 1, RARRAY_AREF(ary, i)))) return Qtrue;
+        }
     }
     else if (!rb_block_given_p()) {
         for (i = 0; i < len; ++i) {
@@ -6327,19 +7944,50 @@ rb_ary_any_p(int argc, VALUE *argv, VALUE ary)
         }
     }
     else {
-	for (i = 0; i < RARRAY_LEN(ary); ++i) {
-	    if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) return Qtrue;
-	}
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) return Qtrue;
+        }
     }
     return Qfalse;
 }
 
 /*
  *  call-seq:
- *     ary.all? [{|obj| block}  ]   -> true or false
- *     ary.all?(pattern)            -> true or false
+ *    all? -> true or false
+ *    all?(object) -> true or false
+ *    all? {|element| ... } -> true or false
  *
- *  See also Enumerable#all?
+ *  Returns whether for every element of +self+,
+ *  a given criterion is satisfied.
+ *
+ *  With no block and no argument,
+ *  returns whether every element of +self+ is truthy:
+ *
+ *    [[], {}, '', 0, 0.0, Object.new].all? # => true  # All truthy objects.
+ *    [[], {}, '', 0, 0.0, nil].all?        # => false # nil is not truthy.
+ *    [[], {}, '', 0, 0.0, false].all?      # => false # false is not truthy.
+ *
+ *  With argument +object+ given, returns whether <tt>object === ele</tt>
+ *  for every element +ele+ in +self+:
+ *
+ *    [0, 0, 0].all?(0)                    # => true
+ *    [0, 1, 2].all?(1)                    # => false
+ *    ['food', 'fool', 'foot'].all?(/foo/) # => true
+ *    ['food', 'drink'].all?(/foo/)        # => false
+ *
+ *  With a block given, calls the block with each element in +self+;
+ *  returns whether the block returns only truthy values:
+ *
+ *    [0, 1, 2].all? { |ele| ele < 3 } # => true
+ *    [0, 1, 2].all? { |ele| ele < 2 } # => false
+ *
+ *  With both a block and argument +object+ given,
+ *  ignores the block and uses +object+ as above.
+ *
+ *  <b>Special case</b>: returns +true+ if +self+ is empty
+ *  (regardless of any given argument or block).
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -6372,10 +8020,35 @@ rb_ary_all_p(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.none? [{|obj| block}  ]   -> true or false
- *     ary.none?(pattern)            -> true or false
+ *    none? -> true or false
+ *    none?(object) -> true or false
+ *    none? {|element| ... } -> true or false
+ *
+ *  Returns +true+ if no element of +self+ meets a given criterion, +false+ otherwise.
+ *
+ *  With no block given and no argument, returns +true+ if +self+ has no truthy elements,
+ *  +false+ otherwise:
  *
- *  See also Enumerable#none?
+ *    [nil, false].none?    # => true
+ *    [nil, 0, false].none? # => false
+ *    [].none?              # => true
+ *
+ *  With argument +object+ given, returns +false+ if for any element +element+,
+ *  <tt>object === element</tt>; +true+ otherwise:
+ *
+ *    ['food', 'drink'].none?(/bar/) # => true
+ *    ['food', 'drink'].none?(/foo/) # => false
+ *    [].none?(/foo/)                # => true
+ *    [0, 1, 2].none?(3)             # => true
+ *    [0, 1, 2].none?(1)             # => false
+ *
+ *  With a block given, calls the block with each element in +self+;
+ *  returns +true+ if the block returns no truthy value, +false+ otherwise:
+ *
+ *    [0, 1, 2].none? {|element| element > 3 } # => true
+ *    [0, 1, 2].none? {|element| element > 1 } # => false
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -6408,10 +8081,38 @@ rb_ary_none_p(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.one? [{|obj| block}  ]   -> true or false
- *     ary.one?(pattern)            -> true or false
+ *    one? -> true or false
+ *    one? {|element| ... } -> true or false
+ *    one?(object) -> true or false
+ *
+ *  Returns +true+ if exactly one element of +self+ meets a given criterion.
+ *
+ *  With no block given and no argument, returns +true+ if +self+ has exactly one truthy element,
+ *  +false+ otherwise:
+ *
+ *    [nil, 0].one? # => true
+ *    [0, 0].one? # => false
+ *    [nil, nil].one? # => false
+ *    [].one? # => false
+ *
+ *  With a block given, calls the block with each element in +self+;
+ *  returns +true+ if the block a truthy value for exactly one element, +false+ otherwise:
+ *
+ *    [0, 1, 2].one? {|element| element > 0 } # => false
+ *    [0, 1, 2].one? {|element| element > 1 } # => true
+ *    [0, 1, 2].one? {|element| element > 2 } # => false
+ *
+ *  With argument +object+ given, returns +true+ if for exactly one element +element+, <tt>object === element</tt>;
+ *  +false+ otherwise:
+ *
+ *    [0, 1, 2].one?(0) # => true
+ *    [0, 0, 1].one?(0) # => false
+ *    [1, 1, 2].one?(0) # => false
+ *    ['food', 'drink'].one?(/bar/) # => false
+ *    ['food', 'drink'].one?(/foo/) # => true
+ *    [].one?(/foo/) # => false
  *
- *  See also Enumerable#one?
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -6453,19 +8154,23 @@ rb_ary_one_p(int argc, VALUE *argv, VALUE ary)
 }
 
 /*
- * call-seq:
- *   ary.dig(idx, ...)                 -> object
+ *  call-seq:
+ *    dig(index, *identifiers) -> object
+ *
+ *  Finds and returns the object in nested object
+ *  specified by +index+ and +identifiers+;
+ *  the nested objects may be instances of various classes.
+ *  See {Dig Methods}[rdoc-ref:dig_methods.rdoc].
  *
- * Extracts the nested value specified by the sequence of <i>idx</i>
- * objects by calling +dig+ at each step, returning +nil+ if any
- * intermediate step is +nil+.
+ *  Examples:
  *
- *   a = [[1, [2, 3]]]
+ *    a = [:foo, [:bar, :baz, [:bat, :bam]]]
+ *    a.dig(1) # => [:bar, :baz, [:bat, :bam]]
+ *    a.dig(1, 2) # => [:bat, :bam]
+ *    a.dig(1, 2, 0) # => :bat
+ *    a.dig(1, 2, 3) # => nil
  *
- *   a.dig(0, 1, 1)                    #=> 3
- *   a.dig(1, 2, 3)                    #=> nil
- *   a.dig(0, 0, 0)                    #=> TypeError: Integer does not have #dig method
- *   [42, {foo: :bar}].dig(1, :foo)    #=> :bar
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -6483,14 +8188,8 @@ finish_exact_sum(long n, VALUE r, VALUE v, int z)
 {
     if (n != 0)
         v = rb_fix_plus(LONG2FIX(n), v);
-    if (r != Qundef) {
-	/* r can be an Integer when mathn is loaded */
-	if (FIXNUM_P(r))
-	    v = rb_fix_plus(r, v);
-	else if (RB_TYPE_P(r, T_BIGNUM))
-	    v = rb_big_plus(r, v);
-	else
-	    v = rb_rational_plus(r, v);
+    if (!UNDEF_P(r)) {
+        v = rb_rational_plus(r, v);
     }
     else if (!n && z) {
         v = rb_fix_plus(LONG2FIX(0), v);
@@ -6500,43 +8199,42 @@ finish_exact_sum(long n, VALUE r, VALUE v, int z)
 
 /*
  * call-seq:
- *   ary.sum(init=0)                    -> number
- *   ary.sum(init=0) {|e| expr }        -> number
+ *   sum(init = 0) -> object
+ *   sum(init = 0) {|element| ... } -> object
  *
- * Returns the sum of elements.
- * For example, [e1, e2, e3].sum returns init + e1 + e2 + e3.
+ *  With no block given, returns the sum of +init+ and all elements of +self+;
+ *  for array +array+ and value +init+, equivalent to:
  *
- * If a block is given, the block is applied to each element
- * before addition.
+ *    sum = init
+ *    array.each {|element| sum += element }
+ *    sum
  *
- * If <i>ary</i> is empty, it returns <i>init</i>.
+ *  For example, <tt>[e0, e1, e2].sum</tt> returns <tt>init + e0 + e1 + e2</tt>.
  *
- *   [].sum                             #=> 0
- *   [].sum(0.0)                        #=> 0.0
- *   [1, 2, 3].sum                      #=> 6
- *   [3, 5.5].sum                       #=> 8.5
- *   [2.5, 3.0].sum(0.0) {|e| e * e }   #=> 15.25
- *   [Object.new].sum                   #=> TypeError
+ *  Examples:
  *
- * The (arithmetic) mean value of an array can be obtained as follows.
+ *    [0, 1, 2, 3].sum                 # => 6
+ *    [0, 1, 2, 3].sum(100)            # => 106
+ *    ['abc', 'def', 'ghi'].sum('jkl') # => "jklabcdefghi"
+ *    [[:foo, :bar], ['foo', 'bar']].sum([2, 3])
+ *    # => [2, 3, :foo, :bar, "foo", "bar"]
  *
- *   mean = ary.sum(0.0) / ary.length
+ *  The +init+ value and elements need not be numeric, but must all be <tt>+</tt>-compatible:
  *
- * This method can be used for non-numeric objects by
- * explicit <i>init</i> argument.
+ *    # Raises TypeError: Array can't be coerced into Integer.
+ *    [[:foo, :bar], ['foo', 'bar']].sum(2)
  *
- *   ["a", "b", "c"].sum("")            #=> "abc"
- *   [[1], [[2]], [3]].sum([])          #=> [1, [2], 3]
+ *  With a block given, calls the block with each element of +self+;
+ *  the block's return value (instead of the element itself) is used as the addend:
  *
- * However, Array#join and Array#flatten is faster than Array#sum for
- * array of strings and array of arrays.
+ *    ['zero', 1, :two].sum('Coerced and concatenated: ') {|element| element.to_s }
+ *    # => "Coerced and concatenated: zero1two"
  *
- *   ["a", "b", "c"].join               #=> "abc"
- *   [[1], [[2]], [3]].flatten(1)       #=> [1, [2], 3]
+ *  Notes:
  *
- *
- * Array#sum method may not respect method redefinition of "+" methods
- * such as Integer#+.
+ *  - Array#join and Array#flatten may be faster than Array#sum
+ *    for an array of strings or an array of arrays.
+ *  - Array#sum method may not respect method redefinition of "+" methods such as Integer#+.
  *
  */
 
@@ -6556,6 +8254,16 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
 
     n = 0;
     r = Qundef;
+
+    bool init_is_float = RB_FLOAT_TYPE_P(v);
+    if (init_is_float) {
+        v = LONG2FIX(0);
+    }
+    else if (!RB_INTEGER_TYPE_P(v) && !RB_TYPE_P(v, T_RATIONAL)) {
+        i = 0;
+        goto init_is_a_value;
+    }
+
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         e = RARRAY_AREF(ary, i);
         if (block_given)
@@ -6567,10 +8275,10 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
                 n = 0;
             }
         }
-        else if (RB_TYPE_P(e, T_BIGNUM))
+        else if (RB_BIGNUM_TYPE_P(e))
             v = rb_big_plus(e, v);
         else if (RB_TYPE_P(e, T_RATIONAL)) {
-            if (r == Qundef)
+            if (UNDEF_P(r))
                 r = e;
             else
                 r = rb_rational_plus(r, e);
@@ -6579,23 +8287,24 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
             goto not_exact;
     }
     v = finish_exact_sum(n, r, v, argc!=0);
+    if (init_is_float) v = rb_float_plus(argv[0], v);
     return v;
 
   not_exact:
     v = finish_exact_sum(n, r, v, i!=0);
 
-    if (RB_FLOAT_TYPE_P(e)) {
+    if (init_is_float ? (--i, e = argv[0], true) : RB_FLOAT_TYPE_P(e)) {
         /*
          * Kahan-Babuska balancing compensated summation algorithm
-         * See http://link.springer.com/article/10.1007/s00607-005-0139-x
+         * See https://link.springer.com/article/10.1007/s00607-005-0139-x
          */
         double f, c;
+        double x, t;
 
         f = NUM2DBL(v);
         c = 0.0;
         goto has_float_value;
         for (; i < RARRAY_LEN(ary); i++) {
-            double x, t;
             e = RARRAY_AREF(ary, i);
             if (block_given)
                 e = rb_yield(e);
@@ -6604,7 +8313,7 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
                 x = RFLOAT_VALUE(e);
             else if (FIXNUM_P(e))
                 x = FIX2LONG(e);
-            else if (RB_TYPE_P(e, T_BIGNUM))
+            else if (RB_BIGNUM_TYPE_P(e))
                 x = rb_big2dbl(e);
             else if (RB_TYPE_P(e, T_RATIONAL))
                 x = rb_num2dbl(e);
@@ -6640,6 +8349,7 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
     }
 
     goto has_some_value;
+    init_is_a_value:
     for (; i < RARRAY_LEN(ary); i++) {
         e = RARRAY_AREF(ary, i);
         if (block_given)
@@ -6650,6 +8360,7 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
     return v;
 }
 
+/* :nodoc: */
 static VALUE
 rb_ary_deconstruct(VALUE ary)
 {
@@ -6657,55 +8368,154 @@ rb_ary_deconstruct(VALUE ary)
 }
 
 /*
- *  Arrays are ordered, integer-indexed collections of any object.
+ *  An \Array object is an ordered, integer-indexed collection of objects,
+ *  called _elements_;
+ *  the object represents
+ *  an {array data structure}[https://en.wikipedia.org/wiki/Array_(data_structure)].
+ *
+ *  An element may be any object (even another array);
+ *  elements may be any mixture of objects of different types.
+ *
+ *  Important data structures that use arrays include:
+ *
+ *  - {Coordinate vector}[https://en.wikipedia.org/wiki/Coordinate_vector].
+ *  - {Matrix}[https://en.wikipedia.org/wiki/Matrix_(mathematics)].
+ *  - {Heap}[https://en.wikipedia.org/wiki/Heap_(data_structure)].
+ *  - {Hash table}[https://en.wikipedia.org/wiki/Hash_table].
+ *  - {Deque (double-ended queue)}[https://en.wikipedia.org/wiki/Double-ended_queue].
+ *  - {Queue}[https://en.wikipedia.org/wiki/Queue_(abstract_data_type)].
+ *  - {Stack}[https://en.wikipedia.org/wiki/Stack_(abstract_data_type)].
+ *
+ *  There are also array-like data structures:
  *
- *  Array indexing starts at 0, as in C or Java.  A negative index is assumed
- *  to be relative to the end of the array---that is, an index of -1 indicates
- *  the last element of the array, -2 is the next to last element in the
- *  array, and so on.
+ *  - {Associative array}[https://en.wikipedia.org/wiki/Associative_array] (see Hash).
+ *  - {Directory}[https://en.wikipedia.org/wiki/Directory_(computing)] (see Dir).
+ *  - {Environment}[https://en.wikipedia.org/wiki/Environment_variable] (see ENV).
+ *  - {Set}[https://en.wikipedia.org/wiki/Set_(abstract_data_type)] (see Set).
+ *  - {String}[https://en.wikipedia.org/wiki/String_(computer_science)] (see String).
+ *
+ *  == \Array Indexes
+ *
+ *  \Array indexing starts at 0, as in C or Java.
+ *
+ *  A non-negative index is an offset from the first element:
+ *
+ *  - Index 0 indicates the first element.
+ *  - Index 1 indicates the second element.
+ *  - ...
+ *
+ *  A negative index is an offset, backwards, from the end of the array:
+ *
+ *  - Index -1 indicates the last element.
+ *  - Index -2 indicates the next-to-last element.
+ *  - ...
+ *
+ *
+ *  === In-Range and Out-of-Range Indexes
+ *
+ *  A non-negative index is <i>in range</i> if and only if it is smaller than
+ *  the size of the array.  For a 3-element array:
+ *
+ *  - Indexes 0 through 2 are in range.
+ *  - Index 3 is out of range.
+ *
+ *  A negative index is <i>in range</i> if and only if its absolute value is
+ *  not larger than the size of the array.  For a 3-element array:
+ *
+ *  - Indexes -1 through -3 are in range.
+ *  - Index -4 is out of range.
+ *
+ *  === Effective Index
+ *
+ *  Although the effective index into an array is always an integer,
+ *  some methods (both within class \Array and elsewhere)
+ *  accept one or more non-integer arguments that are
+ *  {integer-convertible objects}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
  *
  *  == Creating Arrays
  *
- *  A new array can be created by using the literal constructor
- *  <code>[]</code>.  Arrays can contain different types of objects.  For
- *  example, the array below contains an Integer, a String and a Float:
+ *  You can create an \Array object explicitly with:
+ *
+ *  - An {array literal}[rdoc-ref:syntax/literals.rdoc@Array+Literals]:
+ *
+ *      [1, 'one', :one, [2, 'two', :two]]
+ *
+ *  - A {%w or %W string-array Literal}[rdoc-ref:syntax/literals.rdoc@w-and-w-String-Array-Literals]:
+ *
+ *      %w[foo bar baz] # => ["foo", "bar", "baz"]
+ *      %w[1 % *]       # => ["1", "%", "*"]
  *
- *     ary = [1, "two", 3.0] #=> [1, "two", 3.0]
+ *  - A {%i or %I symbol-array Literal}[rdoc-ref:syntax/literals.rdoc@i+and-I-Symbol-Array+Literals]:
  *
- *  An array can also be created by explicitly calling Array.new with zero, one
- *  (the initial size of the Array) or two arguments (the initial size and a
- *  default object).
+ *      %i[foo bar baz] # => [:foo, :bar, :baz]
+ *      %i[1 % *]       # => [:"1", :%, :*]
  *
- *     ary = Array.new    #=> []
- *     Array.new(3)       #=> [nil, nil, nil]
- *     Array.new(3, true) #=> [true, true, true]
+ *  - Method Kernel#Array:
  *
- *  Note that the second argument populates the array with references to the
- *  same object.  Therefore, it is only recommended in cases when you need to
- *  instantiate arrays with natively immutable objects such as Symbols,
- *  numbers, true or false.
+ *      Array(["a", "b"])             # => ["a", "b"]
+ *      Array(1..5)                   # => [1, 2, 3, 4, 5]
+ *      Array(key: :value)            # => [[:key, :value]]
+ *      Array(nil)                    # => []
+ *      Array(1)                      # => [1]
+ *      Array({:a => "a", :b => "b"}) # => [[:a, "a"], [:b, "b"]]
  *
- *  To create an array with separate objects a block can be passed instead.
- *  This method is safe to use with mutable objects such as hashes, strings or
- *  other arrays:
+ *  - Method Array.new:
  *
- *     Array.new(4) {Hash.new}    #=> [{}, {}, {}, {}]
- *     Array.new(4) {|i| i.to_s } #=> ["0", "1", "2", "3"]
+ *      Array.new               # => []
+ *      Array.new(3)            # => [nil, nil, nil]
+ *      Array.new(4) {Hash.new} # => [{}, {}, {}, {}]
+ *      Array.new(3, true)      # => [true, true, true]
  *
- *  This is also a quick way to build up multi-dimensional arrays:
+ *    Note that the last example above populates the array
+ *    with references to the same object.
+ *    This is recommended only in cases where that object is a natively immutable object
+ *    such as a symbol, a numeric, +nil+, +true+, or +false+.
  *
- *     empty_table = Array.new(3) {Array.new(3)}
- *     #=> [[nil, nil, nil], [nil, nil, nil], [nil, nil, nil]]
+ *    Another way to create an array with various objects, using a block;
+ *    this usage is safe for mutable objects such as hashes, strings or
+ *    other arrays:
  *
- *  An array can also be created by using the Array() method, provided by
- *  Kernel, which tries to call #to_ary, then #to_a on its argument.
+ *      Array.new(4) {|i| i.to_s } # => ["0", "1", "2", "3"]
  *
- *	Array({:a => "a", :b => "b"}) #=> [[:a, "a"], [:b, "b"]]
+ *    Here is a way to create a multi-dimensional array:
+ *
+ *      Array.new(3) {Array.new(3)}
+ *      # => [[nil, nil, nil], [nil, nil, nil], [nil, nil, nil]]
+ *
+ *  A number of Ruby methods, both in the core and in the standard library,
+ *  provide instance method +to_a+, which converts an object to an array.
+ *
+ *  - ARGF#to_a
+ *  - Array#to_a
+ *  - Enumerable#to_a
+ *  - Hash#to_a
+ *  - MatchData#to_a
+ *  - NilClass#to_a
+ *  - OptionParser#to_a
+ *  - Range#to_a
+ *  - Set#to_a
+ *  - Struct#to_a
+ *  - Time#to_a
+ *  - Benchmark::Tms#to_a
+ *  - CSV::Table#to_a
+ *  - Enumerator::Lazy#to_a
+ *  - Gem::List#to_a
+ *  - Gem::NameTuple#to_a
+ *  - Gem::Platform#to_a
+ *  - Gem::RequestSet::Lockfile::Tokenizer#to_a
+ *  - Gem::SourceList#to_a
+ *  - OpenSSL::X509::Extension#to_a
+ *  - OpenSSL::X509::Name#to_a
+ *  - Racc::ISet#to_a
+ *  - Rinda::RingFinger#to_a
+ *  - Ripper::Lexer::Elem#to_a
+ *  - RubyVM::InstructionSequence#to_a
+ *  - YAML::DBM#to_a
  *
  *  == Example Usage
  *
- *  In addition to the methods it mixes in through the Enumerable module, the
- *  Array class has proprietary methods for accessing, searching and otherwise
+ *  In addition to the methods it mixes in through the Enumerable module,
+ *  class \Array has proprietary methods for accessing, searching and otherwise
  *  manipulating arrays.
  *
  *  Some of the more common ones are illustrated below.
@@ -6753,9 +8563,9 @@ rb_ary_deconstruct(VALUE ary)
  *
  *     arr.drop(3) #=> [4, 5, 6]
  *
- *  == Obtaining Information about an Array
+ *  == Obtaining Information about an \Array
  *
- *  Arrays keep track of their own length at all times.  To query an array
+ *  An array keeps track of its own length at all times.  To query an array
  *  about the number of elements it contains, use #length, #count or #size.
  *
  *    browsers = ['Chrome', 'Firefox', 'Safari', 'Opera', 'IE']
@@ -6770,7 +8580,7 @@ rb_ary_deconstruct(VALUE ary)
  *
  *    browsers.include?('Konqueror') #=> false
  *
- *  == Adding Items to Arrays
+ *  == Adding Items to an \Array
  *
  *  Items can be added to the end of an array by using either #push or #<<
  *
@@ -6791,7 +8601,7 @@ rb_ary_deconstruct(VALUE ary)
  *     arr.insert(3, 'orange', 'pear', 'grapefruit')
  *     #=> [0, 1, 2, "orange", "pear", "grapefruit", "apple", 3, 4, 5, 6]
  *
- *  == Removing Items from an Array
+ *  == Removing Items from an \Array
  *
  *  The method #pop removes the last element in an array and returns it:
  *
@@ -6831,11 +8641,11 @@ rb_ary_deconstruct(VALUE ary)
  *     arr = [2, 5, 6, 556, 6, 6, 8, 9, 0, 123, 556]
  *     arr.uniq #=> [2, 5, 6, 556, 8, 9, 0, 123]
  *
- *  == Iterating over Arrays
+ *  == Iterating over an \Array
  *
- *  Like all classes that include the Enumerable module, Array has an each
+ *  Like all classes that include the Enumerable module, class \Array has an each
  *  method, which defines what elements should be iterated over and how.  In
- *  case of Array's #each, all elements in the Array instance are yielded to
+ *  case of Array#each, all elements in +self+ are yielded to
  *  the supplied block in sequence.
  *
  *  Note that this operation leaves the array unchanged.
@@ -6861,7 +8671,8 @@ rb_ary_deconstruct(VALUE ary)
  *     arr.map! {|a| a**2}   #=> [1, 4, 9, 16, 25]
  *     arr                   #=> [1, 4, 9, 16, 25]
  *
- *  == Selecting Items from an Array
+ *
+ *  == Selecting Items from an \Array
  *
  *  Elements can be selected from an array according to criteria defined in a
  *  block.  The selection can happen in a destructive or a non-destructive
@@ -6892,18 +8703,183 @@ rb_ary_deconstruct(VALUE ary)
  *     arr.keep_if {|a| a < 4}   #=> [1, 2, 3]
  *     arr                       #=> [1, 2, 3]
  *
+ *  == What's Here
+ *
+ *  First, what's elsewhere. Class \Array:
+ *
+ *  - Inherits from {class Object}[rdoc-ref:Object@Whats-Here].
+ *  - Includes {module Enumerable}[rdoc-ref:Enumerable@Whats-Here],
+ *    which provides dozens of additional methods.
+ *
+ *  Here, class \Array provides methods that are useful for:
+ *
+ *  - {Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array]
+ *  - {Querying}[rdoc-ref:Array@Methods+for+Querying]
+ *  - {Comparing}[rdoc-ref:Array@Methods+for+Comparing]
+ *  - {Fetching}[rdoc-ref:Array@Methods+for+Fetching]
+ *  - {Assigning}[rdoc-ref:Array@Methods+for+Assigning]
+ *  - {Deleting}[rdoc-ref:Array@Methods+for+Deleting]
+ *  - {Combining}[rdoc-ref:Array@Methods+for+Combining]
+ *  - {Iterating}[rdoc-ref:Array@Methods+for+Iterating]
+ *  - {Converting}[rdoc-ref:Array@Methods+for+Converting]
+ *  - {And more....}[rdoc-ref:Array@Other+Methods]
+ *
+ *  === Methods for Creating an \Array
+ *
+ *  - ::[]: Returns a new array populated with given objects.
+ *  - ::new: Returns a new array.
+ *  - ::try_convert: Returns a new array created from a given object.
+ *
+ *  See also {Creating Arrays}[rdoc-ref:Array@Creating+Arrays].
+ *
+ *  === Methods for Querying
+ *
+ *  - #all?: Returns whether all elements meet a given criterion.
+ *  - #any?: Returns whether any element meets a given criterion.
+ *  - #count: Returns the count of elements that meet a given criterion.
+ *  - #empty?: Returns whether there are no elements.
+ *  - #find_index (aliased as #index): Returns the index of the first element that meets a given criterion.
+ *  - #hash: Returns the integer hash code.
+ *  - #include?: Returns whether any element <tt>==</tt> a given object.
+ *  - #length (aliased as #size): Returns the count of elements.
+ *  - #none?: Returns whether no element <tt>==</tt> a given object.
+ *  - #one?: Returns whether exactly one element <tt>==</tt> a given object.
+ *  - #rindex: Returns the index of the last element that meets a given criterion.
+ *
+ *  === Methods for Comparing
+ *
+ *  - #<=>: Returns -1, 0, or 1, as +self+ is less than, equal to, or greater than a given object.
+ *  - #==: Returns whether each element in +self+ is <tt>==</tt> to the corresponding element in a given object.
+ *  - #eql?: Returns whether each element in +self+ is <tt>eql?</tt> to the corresponding element in a given object.
+
+ *  === Methods for Fetching
+ *
+ *  These methods do not modify +self+.
+ *
+ *  - #[] (aliased as #slice): Returns consecutive elements as determined by a given argument.
+ *  - #assoc: Returns the first element that is an array whose first element <tt>==</tt> a given object.
+ *  - #at: Returns the element at a given offset.
+ *  - #bsearch: Returns an element selected via a binary search as determined by a given block.
+ *  - #bsearch_index: Returns the index of an element selected via a binary search as determined by a given block.
+ *  - #compact: Returns an array containing all non-+nil+ elements.
+ *  - #dig: Returns the object in nested objects that is specified by a given index and additional arguments.
+ *  - #drop: Returns trailing elements as determined by a given index.
+ *  - #drop_while: Returns trailing elements as determined by a given block.
+ *  - #fetch: Returns the element at a given offset.
+ *  - #fetch_values: Returns elements at given offsets.
+ *  - #first: Returns one or more leading elements.
+ *  - #last: Returns one or more trailing elements.
+ *  - #max: Returns one or more maximum-valued elements, as determined by <tt>#<=></tt> or a given block.
+ *  - #min: Returns one or more minimum-valued elements, as determined by <tt>#<=></tt> or a given block.
+ *  - #minmax: Returns the minimum-valued and maximum-valued elements, as determined by <tt>#<=></tt> or a given block.
+ *  - #rassoc: Returns the first element that is an array whose second element <tt>==</tt> a given object.
+ *  - #reject: Returns an array containing elements not rejected by a given block.
+ *  - #reverse: Returns all elements in reverse order.
+ *  - #rotate: Returns all elements with some rotated from one end to the other.
+ *  - #sample: Returns one or more random elements.
+ *  - #select (aliased as #filter): Returns an array containing elements selected by a given block.
+ *  - #shuffle: Returns elements in a random order.
+ *  - #sort: Returns all elements in an order determined by <tt>#<=></tt> or a given block.
+ *  - #take: Returns leading elements as determined by a given index.
+ *  - #take_while: Returns leading elements as determined by a given block.
+ *  - #uniq: Returns an array containing non-duplicate elements.
+ *  - #values_at: Returns the elements at given offsets.
+ *
+ *  === Methods for Assigning
+ *
+ *  These methods add, replace, or reorder elements in +self+.
+ *
+ *  - #<<: Appends an element.
+ *  - #[]=: Assigns specified elements with a given object.
+ *  - #concat: Appends all elements from given arrays.
+ *  - #fill: Replaces specified elements with specified objects.
+ *  - #flatten!: Replaces each nested array in +self+ with the elements from that array.
+ *  - #initialize_copy (aliased as #replace): Replaces the content of +self+ with the content of a given array.
+ *  - #insert: Inserts given objects at a given offset; does not replace elements.
+ *  - #push (aliased as #append): Appends elements.
+ *  - #reverse!: Replaces +self+ with its elements reversed.
+ *  - #rotate!: Replaces +self+ with its elements rotated.
+ *  - #shuffle!: Replaces +self+ with its elements in random order.
+ *  - #sort!: Replaces +self+ with its elements sorted, as determined by <tt>#<=></tt> or a given block.
+ *  - #sort_by!: Replaces +self+ with its elements sorted, as determined by a given block.
+ *  - #unshift (aliased as #prepend): Prepends leading elements.
+ *
+ *  === Methods for Deleting
+ *
+ *  Each of these methods removes elements from +self+:
+ *
+ *  - #clear: Removes all elements.
+ *  - #compact!: Removes all +nil+ elements.
+ *  - #delete: Removes elements equal to a given object.
+ *  - #delete_at: Removes the element at a given offset.
+ *  - #delete_if: Removes elements specified by a given block.
+ *  - #keep_if: Removes elements not specified by a given block.
+ *  - #pop: Removes and returns the last element.
+ *  - #reject!: Removes elements specified by a given block.
+ *  - #select! (aliased as #filter!): Removes elements not specified by a given block.
+ *  - #shift:  Removes and returns the first element.
+ *  - #slice!: Removes and returns a sequence of elements.
+ *  - #uniq!: Removes duplicates.
+ *
+ *  === Methods for Combining
+ *
+ *  - #&: Returns an array containing elements found both in +self+ and a given array.
+ *  - #+: Returns an array containing all elements of +self+ followed by all elements of a given array.
+ *  - #-: Returns an array containing all elements of +self+ that are not found in a given array.
+ *  - #|: Returns an array containing all element of +self+ and all elements of a given array, duplicates removed.
+ *  - #difference: Returns an array containing all elements of +self+ that are not found in any of the given arrays..
+ *  - #intersection: Returns an array containing elements found both in +self+ and in each given array.
+ *  - #product: Returns or yields all combinations of elements from +self+ and given arrays.
+ *  - #reverse: Returns an array containing all elements of +self+ in reverse order.
+ *  - #union: Returns an array containing all elements of +self+ and all elements of given arrays, duplicates removed.
+ *
+ *  === Methods for Iterating
+ *
+ *  - #combination: Calls a given block with combinations of elements of +self+; a combination does not use the same element more than once.
+ *  - #cycle: Calls a given block with each element, then does so again, for a specified number of times, or forever.
+ *  - #each: Passes each element to a given block.
+ *  - #each_index: Passes each element index to a given block.
+ *  - #permutation: Calls a given block with permutations of elements of +self+; a permutation does not use the same element more than once.
+ *  - #repeated_combination: Calls a given block with combinations of elements of +self+; a combination may use the same element more than once.
+ *  - #repeated_permutation: Calls a given block with permutations of elements of +self+; a permutation may use the same element more than once.
+ *  - #reverse_each:  Passes each element, in reverse order, to a given block.
+ *
+ *  === Methods for Converting
+ *
+ *  - #collect (aliased as #map): Returns an array containing the block return-value for each element.
+ *  - #collect! (aliased as #map!): Replaces each element with a block return-value.
+ *  - #flatten: Returns an array that is a recursive flattening of +self+.
+ *  - #inspect (aliased as #to_s): Returns a new String containing the elements.
+ *  - #join: Returns a new String containing the elements joined by the field separator.
+ *  - #to_a: Returns +self+ or a new array containing all elements.
+ *  - #to_ary: Returns +self+.
+ *  - #to_h: Returns a new hash formed from the elements.
+ *  - #transpose: Transposes +self+, which must be an array of arrays.
+ *  - #zip: Returns a new array of arrays containing +self+ and given arrays.
+ *
+ *  === Other Methods
+ *
+ *  - #*: Returns one of the following:
+ *
+ *    - With integer argument +n+, a new array that is the concatenation
+ *      of +n+ copies of +self+.
+ *    - With string argument +field_separator+, a new string that is equivalent to
+ *      <tt>join(field_separator)</tt>.
+ *
+ *  - #pack: Packs the elements into a binary sequence.
+ *  - #sum: Returns a sum of elements according to either <tt>+</tt> or a given block.
  */
 
 void
 Init_Array(void)
 {
-#undef rb_intern
-#define rb_intern(str) rb_intern_const(str)
+    fake_ary_flags = init_fake_ary_flags();
 
     rb_cArray  = rb_define_class("Array", rb_cObject);
     rb_include_module(rb_cArray, rb_mEnumerable);
 
     rb_define_alloc_func(rb_cArray, empty_ary_alloc);
+    rb_define_singleton_method(rb_cArray, "new", rb_ary_s_new, -1);
     rb_define_singleton_method(rb_cArray, "[]", rb_ary_s_create, -1);
     rb_define_singleton_method(rb_cArray, "try_convert", rb_ary_s_try_convert, 1);
     rb_define_method(rb_cArray, "initialize", rb_ary_initialize, -1);
@@ -6923,11 +8899,11 @@ Init_Array(void)
     rb_define_method(rb_cArray, "[]=", rb_ary_aset, -1);
     rb_define_method(rb_cArray, "at", rb_ary_at, 1);
     rb_define_method(rb_cArray, "fetch", rb_ary_fetch, -1);
-    rb_define_method(rb_cArray, "first", rb_ary_first, -1);
-    rb_define_method(rb_cArray, "last", rb_ary_last, -1);
     rb_define_method(rb_cArray, "concat", rb_ary_concat_multi, -1);
     rb_define_method(rb_cArray, "union", rb_ary_union_multi, -1);
     rb_define_method(rb_cArray, "difference", rb_ary_difference_multi, -1);
+    rb_define_method(rb_cArray, "intersection", rb_ary_intersection_multi, -1);
+    rb_define_method(rb_cArray, "intersect?", rb_ary_intersect_p, 1);
     rb_define_method(rb_cArray, "<<", rb_ary_push, 1);
     rb_define_method(rb_cArray, "push", rb_ary_push_m, -1);
     rb_define_alias(rb_cArray,  "append", "push");
@@ -6940,8 +8916,11 @@ Init_Array(void)
     rb_define_method(rb_cArray, "each_index", rb_ary_each_index, 0);
     rb_define_method(rb_cArray, "reverse_each", rb_ary_reverse_each, 0);
     rb_define_method(rb_cArray, "length", rb_ary_length, 0);
-    rb_define_alias(rb_cArray,  "size", "length");
+    rb_define_method(rb_cArray, "size", rb_ary_length, 0);
     rb_define_method(rb_cArray, "empty?", rb_ary_empty_p, 0);
+    rb_define_method(rb_cArray, "find", rb_ary_find, -1);
+    rb_define_method(rb_cArray, "detect", rb_ary_find, -1);
+    rb_define_method(rb_cArray, "rfind", rb_ary_rfind, -1);
     rb_define_method(rb_cArray, "find_index", rb_ary_index, -1);
     rb_define_method(rb_cArray, "index", rb_ary_index, -1);
     rb_define_method(rb_cArray, "rindex", rb_ary_rindex, -1);
@@ -7000,9 +8979,6 @@ Init_Array(void)
     rb_define_method(rb_cArray, "flatten", rb_ary_flatten, -1);
     rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, -1);
     rb_define_method(rb_cArray, "count", rb_ary_count, -1);
-    rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, -1);
-    rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, -1);
-    rb_define_method(rb_cArray, "sample", rb_ary_sample, -1);
     rb_define_method(rb_cArray, "cycle", rb_ary_cycle, -1);
     rb_define_method(rb_cArray, "permutation", rb_ary_permutation, -1);
     rb_define_method(rb_cArray, "combination", rb_ary_combination, 1);
@@ -7022,8 +8998,12 @@ Init_Array(void)
     rb_define_method(rb_cArray, "one?", rb_ary_one_p, -1);
     rb_define_method(rb_cArray, "dig", rb_ary_dig, -1);
     rb_define_method(rb_cArray, "sum", rb_ary_sum, -1);
+    rb_define_method(rb_cArray, "freeze", rb_ary_freeze, 0);
 
     rb_define_method(rb_cArray, "deconstruct", rb_ary_deconstruct, 0);
 
-    id_random = rb_intern("random");
+    rb_cArray_empty_frozen = RB_OBJ_SET_SHAREABLE(rb_ary_freeze(rb_ary_new()));
+    rb_vm_register_global_object(rb_cArray_empty_frozen);
 }
+
+#include "array.rbinc"
diff --git a/array.rb b/array.rb
new file mode 100644
index 0000000000..7ee4e09a4c
--- /dev/null
+++ b/array.rb
@@ -0,0 +1,307 @@
+class Array
+  # call-seq:
+  #   shuffle!(random: Random) -> self
+  #
+  # Shuffles all elements in +self+ into a random order,
+  # as selected by the object given by the keyword argument +random+.
+  # Returns +self+:
+  #
+  #   a =             [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+  #   a.shuffle! # => [5, 3, 8, 7, 6, 1, 9, 4, 2, 0]
+  #   a.shuffle! # => [9, 4, 0, 6, 2, 8, 1, 5, 3, 7]
+  #
+  # Duplicate elements are included:
+  #
+  #   a =             [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
+  #   a.shuffle! # => [1, 0, 0, 1, 1, 0, 1, 0, 0, 1]
+  #   a.shuffle! # => [0, 1, 0, 1, 1, 0, 1, 0, 1, 0]
+  #
+  # The object given with the keyword argument +random+ is used as the random number generator.
+  #
+  # Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
+  def shuffle!(random: Random)
+    Primitive.rb_ary_shuffle_bang(random)
+  end
+
+  # call-seq:
+  #   shuffle(random: Random) -> new_array
+  #
+  # Returns a new array containing all elements from +self+ in a random order,
+  # as selected by the object given by the keyword argument +random+:
+  #
+  #   a =            [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+  #   a.shuffle # => [0, 8, 1, 9, 6, 3, 4, 7, 2, 5]
+  #   a.shuffle # => [8, 9, 0, 5, 1, 2, 6, 4, 7, 3]
+  #
+  # Duplicate elements are included:
+  #
+  #   a =            [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
+  #   a.shuffle # => [1, 0, 1, 1, 0, 0, 1, 0, 0, 1]
+  #   a.shuffle # => [1, 1, 0, 0, 0, 1, 1, 0, 0, 1]
+  #
+  # The object given with the keyword argument +random+ is used as the random number generator.
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
+  def shuffle(random: Random)
+    Primitive.rb_ary_shuffle(random)
+  end
+
+  # call-seq:
+  #   sample(random: Random) -> object
+  #   sample(count, random: Random) -> new_ary
+  #
+  # Returns random elements from +self+,
+  # as selected by the object given by the keyword argument +random+.
+  #
+  # With no argument +count+ given, returns one random element from +self+:
+  #
+  #   a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+  #   a.sample # => 3
+  #   a.sample # => 8
+  #
+  # Returns +nil+ if +self+ is empty:
+  #
+  #   [].sample # => nil
+  #
+  # With a non-negative numeric argument +count+ given,
+  # returns a new array containing +count+ random elements from +self+:
+  #
+  #   a.sample(3) # => [8, 9, 2]
+  #   a.sample(6) # => [9, 6, 0, 3, 1, 4]
+  #
+  # The order of the result array is unrelated to the order of +self+.
+  #
+  # Returns a new empty array if +self+ is empty:
+  #
+  #   [].sample(4) # => []
+  #
+  # May return duplicates in +self+:
+  #
+  #   a = [1, 1, 1, 2, 2, 3]
+  #   a.sample(a.size) # => [1, 1, 3, 2, 1, 2]
+  #
+  # Returns no more than <tt>a.size</tt> elements
+  # (because no new duplicates are introduced):
+  #
+  #   a.sample(50) # => [6, 4, 1, 8, 5, 9, 0, 2, 3, 7]
+  #
+  # The object given with the keyword argument +random+ is used as the random number generator:
+  #
+  #   a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+  #   a.sample(random: Random.new(1))     # => 6
+  #   a.sample(4, random: Random.new(1))  # => [6, 10, 9, 2]
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
+  def sample(n = (ary = false), random: Random)
+    if Primitive.mandatory_only?
+      # Primitive.cexpr! %{ rb_ary_sample(self, rb_cRandom, Qfalse, Qfalse) }
+      Primitive.ary_sample0
+    else
+      # Primitive.cexpr! %{ rb_ary_sample(self, random, n, ary) }
+      Primitive.ary_sample(random, n, ary)
+    end
+  end
+
+  # call-seq:
+  #   first -> object or nil
+  #   first(count) -> new_array
+  #
+  # Returns elements from +self+, or +nil+; does not modify +self+.
+  #
+  # With no argument given, returns the first element (if available):
+  #
+  #   a = [:foo, 'bar', 2]
+  #   a.first # => :foo
+  #   a # => [:foo, "bar", 2]
+  #
+  # If +self+ is empty, returns +nil+.
+  #
+  #   [].first # => nil
+  #
+  # With a non-negative integer argument +count+ given,
+  # returns the first +count+ elements (as available) in a new array:
+  #
+  #   a.first(0)  # => []
+  #   a.first(2)  # => [:foo, "bar"]
+  #   a.first(50) # => [:foo, "bar", 2]
+  #
+  # Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
+  def first n = unspecified = true
+    if Primitive.mandatory_only?
+      Primitive.attr! :leaf
+      Primitive.cexpr! %q{ ary_first(self) }
+    else
+      if unspecified
+        Primitive.cexpr! %q{ ary_first(self) }
+      else
+        Primitive.cexpr! %q{  ary_take_first_or_last_n(self, NUM2LONG(n), ARY_TAKE_FIRST) }
+      end
+    end
+  end
+
+  # call-seq:
+  #  last  -> last_object or nil
+  #  last(count) -> new_array
+  #
+  # Returns elements from +self+, or +nil+; +self+ is not modified.
+  #
+  # With no argument given, returns the last element, or +nil+ if +self+ is empty:
+  #
+  #   a = [:foo, 'bar', 2]
+  #   a.last # => 2
+  #   a # => [:foo, "bar", 2]
+  #   [].last # => nil
+  #
+  #
+  # With non-negative integer argument +count+ given,
+  # returns a new array containing the trailing +count+ elements of +self+, as available:
+  #
+  #   a = [:foo, 'bar', 2]
+  #   a.last(2)  # => ["bar", 2]
+  #   a.last(50) # => [:foo, "bar", 2]
+  #   a.last(0)  # => []
+  #   [].last(3) # => []
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
+  def last n = unspecified = true
+    if Primitive.mandatory_only?
+      Primitive.attr! :leaf
+      Primitive.cexpr! %q{ ary_last(self) }
+    else
+      if unspecified
+        Primitive.cexpr! %q{ ary_last(self) }
+      else
+        Primitive.cexpr! %q{ ary_take_first_or_last_n(self, NUM2LONG(n), ARY_TAKE_LAST) }
+      end
+    end
+  end
+
+  # call-seq:
+  #   fetch_values(*indexes) -> new_array
+  #   fetch_values(*indexes) { |index| ... } -> new_array
+  #
+  # With no block given, returns a new array containing the elements of +self+
+  # at the offsets specified by +indexes+. Each of the +indexes+ must be an
+  # {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]:
+  #
+  #    a = [:foo, :bar, :baz]
+  #    a.fetch_values(2, 0)   # => [:baz, :foo]
+  #    a.fetch_values(2.1, 0) # => [:baz, :foo]
+  #    a.fetch_values         # => []
+  #
+  # For a negative index, counts backwards from the end of the array:
+  #
+  #    a.fetch_values(-2, -1) # [:bar, :baz]
+  #
+  # When no block is given, raises an exception if any index is out of range.
+  #
+  # With a block given, for each index:
+  #
+  # - If the index is in range, uses an element of +self+ (as above).
+  # - Otherwise, calls the block with the index and uses the block's return value.
+  #
+  # Example:
+  #
+  #   a = [:foo, :bar, :baz]
+  #   a.fetch_values(1, 0, 42, 777) { |index| index.to_s }
+  #   # => [:bar, :foo, "42", "777"]
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
+  def fetch_values(*indexes, &block)
+    indexes.map! { |i| fetch(i, &block) }
+    indexes
+  end
+
+  with_jit do
+    if Primitive.rb_builtin_basic_definition_p(:each)
+      undef :each
+
+      def each # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+        i = 0
+        until Primitive.rb_jit_ary_at_end(i)
+          yield Primitive.rb_jit_ary_at(i)
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        self
+      end
+    end
+
+    if Primitive.rb_builtin_basic_definition_p(:map)
+      undef :map
+
+      def map # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+
+        i = 0
+        result = Primitive.ary_sized_alloc
+        until Primitive.rb_jit_ary_at_end(i)
+          value = yield(Primitive.rb_jit_ary_at(i))
+          Primitive.rb_jit_ary_push(result, value)
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        result
+      end
+
+      if Primitive.rb_builtin_basic_definition_p(:collect)
+        undef :collect
+        alias collect map
+      end
+    end
+
+    if Primitive.rb_builtin_basic_definition_p(:select)
+      undef :select
+
+      def select # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+
+        i = 0
+        result = Primitive.ary_sized_alloc
+        until Primitive.rb_jit_ary_at_end(i)
+          value = Primitive.rb_jit_ary_at(i)
+          if yield value
+            Primitive.rb_jit_ary_push(result, value)
+          end
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        result
+      end
+
+      if Primitive.rb_builtin_basic_definition_p(:filter)
+        undef :filter
+        alias filter select
+      end
+    end
+
+    if Primitive.rb_builtin_basic_definition_p(:find)
+      undef :find
+
+      def find(if_none_proc = nil) # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+        i = 0
+        until Primitive.rb_jit_ary_at_end(i)
+          value = Primitive.rb_jit_ary_at(i)
+          return value if yield(value)
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        if_none_proc&.call
+      end
+    end
+  end
+end
diff --git a/ast.c b/ast.c
index 7f54d859ef..1ddc2b5791 100644
--- a/ast.c
+++ b/ast.c
@@ -1,32 +1,44 @@
 /* indent-tabs-mode: nil */
+#include "internal.h"
+#include "internal/ruby_parser.h"
+#include "internal/symbol.h"
+#include "internal/warnings.h"
+#include "iseq.h"
+#include "node.h"
 #include "ruby.h"
 #include "ruby/encoding.h"
 #include "ruby/util.h"
-#include "internal.h"
-#include "node.h"
 #include "vm_core.h"
-#include "iseq.h"
+
+#include "builtin.h"
 
 static VALUE rb_mAST;
 static VALUE rb_cNode;
+static VALUE rb_cLocation;
 
 struct ASTNodeData {
-    rb_ast_t *ast;
-    NODE *node;
+    VALUE ast_value;
+    const NODE *node;
 };
 
 static void
 node_gc_mark(void *ptr)
 {
     struct ASTNodeData *data = (struct ASTNodeData *)ptr;
-    rb_gc_mark((VALUE)data->ast);
+    rb_gc_mark(data->ast_value);
 }
 
 static size_t
 node_memsize(const void *ptr)
 {
     struct ASTNodeData *data = (struct ASTNodeData *)ptr;
-    return rb_ast_memsize(data->ast);
+    size_t size = sizeof(struct ASTNodeData);
+    if (data->ast_value) {
+        rb_ast_t *ast = rb_ruby_ast_data_get(data->ast_value);
+        size += rb_ast_memsize(ast);
+    }
+
+    return size;
 }
 
 static const rb_data_type_t rb_node_type = {
@@ -36,32 +48,57 @@ static const rb_data_type_t rb_node_type = {
     RUBY_TYPED_FREE_IMMEDIATELY,
 };
 
+struct ASTLocationData {
+    int first_lineno;
+    int first_column;
+    int last_lineno;
+    int last_column;
+};
+
+static void
+location_gc_mark(void *ptr)
+{
+}
+
+static size_t
+location_memsize(const void *ptr)
+{
+    return sizeof(struct ASTLocationData);
+}
+
+static const rb_data_type_t rb_location_type = {
+    "AST/location",
+    {location_gc_mark, RUBY_TYPED_DEFAULT_FREE, location_memsize,},
+    0, 0,
+    RUBY_TYPED_FREE_IMMEDIATELY,
+};
+
+
 static VALUE rb_ast_node_alloc(VALUE klass);
 
 static void
-setup_node(VALUE obj, rb_ast_t *ast, NODE *node)
+setup_node(VALUE obj, VALUE ast_value, const NODE *node)
 {
     struct ASTNodeData *data;
 
     TypedData_Get_Struct(obj, struct ASTNodeData, &rb_node_type, data);
-    data->ast = ast;
+    data->ast_value = ast_value;
     data->node = node;
 }
 
 static VALUE
-ast_new_internal(rb_ast_t *ast, NODE *node)
+ast_new_internal(VALUE ast_value, const NODE *node)
 {
     VALUE obj;
 
     obj = rb_ast_node_alloc(rb_cNode);
-    setup_node(obj, ast, node);
+    setup_node(obj, ast_value, node);
 
     return obj;
 }
 
-static VALUE rb_ast_parse_str(VALUE str);
-static VALUE rb_ast_parse_file(VALUE path);
-static VALUE rb_ast_parse_array(VALUE array);
+static VALUE rb_ast_parse_str(VALUE str, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens);
+static VALUE rb_ast_parse_file(VALUE path, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens);
 
 static VALUE
 ast_parse_new(void)
@@ -70,102 +107,77 @@ ast_parse_new(void)
 }
 
 static VALUE
-ast_parse_done(rb_ast_t *ast)
+ast_parse_done(VALUE ast_value)
 {
+    rb_ast_t *ast = rb_ruby_ast_data_get(ast_value);
+
     if (!ast->body.root) {
         rb_ast_dispose(ast);
         rb_exc_raise(GET_EC()->errinfo);
     }
 
-    return ast_new_internal(ast, (NODE *)ast->body.root);
+    return ast_new_internal(ast_value, (NODE *)ast->body.root);
 }
 
-/*
- *  call-seq:
- *     RubyVM::AbstractSyntaxTree.parse(string) -> RubyVM::AbstractSyntaxTree::Node
- *
- *  Parses the given _string_ into an abstract syntax tree,
- *  returning the root node of that tree.
- *
- *  SyntaxError is raised if the given _string_ is invalid syntax.
- *
- *    RubyVM::AbstractSyntaxTree.parse("x = 1 + 2")
- *    # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-1:9>
- */
 static VALUE
-rb_ast_s_parse(VALUE module, VALUE str)
+setup_vparser(VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
-    return rb_ast_parse_str(str);
+    VALUE vparser = ast_parse_new();
+    if (RTEST(keep_script_lines)) rb_parser_set_script_lines(vparser);
+    if (RTEST(error_tolerant)) rb_parser_error_tolerant(vparser);
+    if (RTEST(keep_tokens)) rb_parser_keep_tokens(vparser);
+    return vparser;
 }
 
 static VALUE
-rb_ast_parse_str(VALUE str)
+ast_s_parse(rb_execution_context_t *ec, VALUE module, VALUE str, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
-    rb_ast_t *ast = 0;
+    return rb_ast_parse_str(str, keep_script_lines, error_tolerant, keep_tokens);
+}
 
+static VALUE
+rb_ast_parse_str(VALUE str, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
+{
+    VALUE ast_value = Qnil;
     StringValue(str);
-    ast = rb_parser_compile_string_path(ast_parse_new(), Qnil, str, 1);
-    return ast_parse_done(ast);
+    VALUE vparser = setup_vparser(keep_script_lines, error_tolerant, keep_tokens);
+    ast_value = rb_parser_compile_string_path(vparser, Qnil, str, 1);
+    return ast_parse_done(ast_value);
 }
 
-/*
- *  call-seq:
- *     RubyVM::AbstractSyntaxTree.parse_file(pathname) -> RubyVM::AbstractSyntaxTree::Node
- *
- *   Reads the file from _pathname_, then parses it like ::parse,
- *   returning the root node of the abstract syntax tree.
- *
- *   SyntaxError is raised if _pathname_'s contents are not
- *   valid Ruby syntax.
- *
- *     RubyVM::AbstractSyntaxTree.parse_file("my-app/app.rb")
- *     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-31:3>
- */
 static VALUE
-rb_ast_s_parse_file(VALUE module, VALUE path)
+ast_s_parse_file(rb_execution_context_t *ec, VALUE module, VALUE path, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
-    return rb_ast_parse_file(path);
+    return rb_ast_parse_file(path, keep_script_lines, error_tolerant, keep_tokens);
 }
 
 static VALUE
-rb_ast_parse_file(VALUE path)
+rb_ast_parse_file(VALUE path, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
     VALUE f;
-    rb_ast_t *ast = 0;
+    VALUE ast_value = Qnil;
     rb_encoding *enc = rb_utf8_encoding();
 
-    FilePathValue(path);
     f = rb_file_open_str(path, "r");
     rb_funcall(f, rb_intern("set_encoding"), 2, rb_enc_from_encoding(enc), rb_str_new_cstr("-"));
-    ast = rb_parser_compile_file_path(ast_parse_new(), Qnil, f, 1);
+    VALUE vparser = setup_vparser(keep_script_lines, error_tolerant, keep_tokens);
+    ast_value = rb_parser_compile_file_path(vparser, Qnil, f, 1);
     rb_io_close(f);
-    return ast_parse_done(ast);
+    return ast_parse_done(ast_value);
 }
 
 static VALUE
-lex_array(VALUE array, int index)
+rb_ast_parse_array(VALUE array, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
-    VALUE str = rb_ary_entry(array, index);
-    if (!NIL_P(str)) {
-        StringValue(str);
-        if (!rb_enc_asciicompat(rb_enc_get(str))) {
-            rb_raise(rb_eArgError, "invalid source encoding");
-        }
-    }
-    return str;
-}
-
-static VALUE
-rb_ast_parse_array(VALUE array)
-{
-    rb_ast_t *ast = 0;
+    VALUE ast_value = Qnil;
 
     array = rb_check_array_type(array);
-    ast = rb_parser_compile_generic(ast_parse_new(), lex_array, Qnil, array, 1);
-    return ast_parse_done(ast);
+    VALUE vparser = setup_vparser(keep_script_lines, error_tolerant, keep_tokens);
+    ast_value = rb_parser_compile_array(vparser, Qnil, array, 1);
+    return ast_parse_done(ast_value);
 }
 
-static VALUE node_children(rb_ast_t*, NODE*);
+static VALUE node_children(VALUE, const NODE*);
 
 static VALUE
 node_find(VALUE self, const int node_id)
@@ -177,7 +189,7 @@ node_find(VALUE self, const int node_id)
 
     if (nd_node_id(data->node) == node_id) return self;
 
-    ary = node_children(data->ast, data->node);
+    ary = node_children(data->ast_value, data->node);
 
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         VALUE child = RARRAY_AREF(ary, i);
@@ -194,66 +206,74 @@ node_find(VALUE self, const int node_id)
 extern VALUE rb_e_script;
 
 static VALUE
-script_lines(VALUE path)
-{
-    VALUE hash, lines;
-    ID script_lines;
-    CONST_ID(script_lines, "SCRIPT_LINES__");
-    if (!rb_const_defined_at(rb_cObject, script_lines)) return Qnil;
-    hash = rb_const_get_at(rb_cObject, script_lines);
-    if (!RB_TYPE_P(hash, T_HASH)) return Qnil;
-    lines = rb_hash_lookup(hash, path);
-    if (!RB_TYPE_P(lines, T_ARRAY)) return Qnil;
-    return lines;
-}
-
-/*
- *  call-seq:
- *     RubyVM::AbstractSyntaxTree.of(proc)   -> RubyVM::AbstractSyntaxTree::Node
- *     RubyVM::AbstractSyntaxTree.of(method) -> RubyVM::AbstractSyntaxTree::Node
- *
- *   Returns AST nodes of the given _proc_ or _method_.
- *
- *     RubyVM::AbstractSyntaxTree.of(proc {1 + 2})
- *     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:35-1:42>
- *
- *     def hello
- *       puts "hello, world"
- *     end
- *
- *     RubyVM::AbstractSyntaxTree.of(method(:hello))
- *     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-3:3>
- */
-static VALUE
-rb_ast_s_of(VALUE module, VALUE body)
-{
-    VALUE path, node, lines;
+node_id_for_backtrace_location(rb_execution_context_t *ec, VALUE module, VALUE location)
+{
     int node_id;
-    const rb_iseq_t *iseq = NULL;
 
-    if (rb_obj_is_proc(body)) {
-        iseq = vm_proc_iseq(body);
+    if (!rb_frame_info_p(location)) {
+        rb_raise(rb_eTypeError, "Thread::Backtrace::Location object expected");
+    }
 
-        if (!rb_obj_is_iseq((VALUE)iseq)) {
-            iseq = NULL;
-        }
+    node_id = rb_get_node_id_from_frame_info(location);
+    if (node_id == -1) {
+        return Qnil;
+    }
+
+    return INT2NUM(node_id);
+}
+
+static VALUE
+ast_s_of(rb_execution_context_t *ec, VALUE module, VALUE body, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
+{
+    VALUE node, lines = Qnil;
+    const rb_iseq_t *iseq;
+    int node_id;
+
+    if (rb_frame_info_p(body)) {
+        iseq = rb_get_iseq_from_frame_info(body);
+        node_id = rb_get_node_id_from_frame_info(body);
     }
     else {
-        iseq = rb_method_iseq(body);
+        iseq = NULL;
+
+        if (rb_obj_is_proc(body)) {
+            iseq = vm_proc_iseq(body);
+
+            if (!rb_obj_is_iseq((VALUE)iseq)) return Qnil;
+        }
+        else {
+            iseq = rb_method_iseq(body);
+        }
+        if (iseq) {
+            node_id = ISEQ_BODY(iseq)->location.node_id;
+        }
+    }
+
+    if (!iseq) {
+        return Qnil;
+    }
+
+    if (ISEQ_BODY(iseq)->prism) {
+        rb_raise(rb_eRuntimeError, "cannot get AST for ISEQ compiled by prism");
     }
 
-    if (!iseq) return Qnil;
+    lines = ISEQ_BODY(iseq)->variable.script_lines;
 
-    path = rb_iseq_path(iseq);
-    node_id = iseq->body->location.node_id;
-    if (!NIL_P(lines = script_lines(path))) {
-        node = rb_ast_parse_array(lines);
+    VALUE path = rb_iseq_path(iseq);
+    int e_option = RSTRING_LEN(path) == 2 && memcmp(RSTRING_PTR(path), "-e", 2) == 0;
+
+    if (NIL_P(lines) && rb_iseq_from_eval_p(iseq) && !e_option) {
+        rb_raise(rb_eArgError, "cannot get AST for method defined in eval");
+    }
+
+    if (!NIL_P(lines)) {
+        node = rb_ast_parse_array(lines, keep_script_lines, error_tolerant, keep_tokens);
     }
-    else if (RSTRING_LEN(path) == 2 && memcmp(RSTRING_PTR(path), "-e", 2) == 0) {
-        node = rb_ast_parse_str(rb_e_script);
+    else if (e_option) {
+        node = rb_ast_parse_str(rb_e_script, keep_script_lines, error_tolerant, keep_tokens);
     }
     else {
-        node = rb_ast_parse_file(path);
+        node = rb_ast_parse_file(path, keep_script_lines, error_tolerant, keep_tokens);
     }
 
     return node_find(node, node_id);
@@ -274,19 +294,8 @@ node_type_to_str(const NODE *node)
     return (ruby_node_name(nd_type(node)) + rb_strlen_lit("NODE_"));
 }
 
-/*
- *  call-seq:
- *     node.type -> symbol
- *
- *  Returns the type of this node as a symbol.
- *
- *    root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2")
- *    root.type # => :SCOPE
- *    call = root.children[2]
- *    call.type # => :OPCALL
- */
 static VALUE
-rb_ast_node_type(VALUE self)
+ast_node_type(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
@@ -294,10 +303,19 @@ rb_ast_node_type(VALUE self)
     return rb_sym_intern_ascii_cstr(node_type_to_str(data->node));
 }
 
-#define NEW_CHILD(ast, node) node ? ast_new_internal(ast, node) : Qnil
+static VALUE
+ast_node_node_id(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return INT2FIX(nd_node_id(data->node));
+}
+
+#define NEW_CHILD(ast_value, node) (node ? ast_new_internal(ast_value, node) : Qnil)
 
 static VALUE
-rb_ary_new_from_node_args(rb_ast_t *ast, long n, ...)
+rb_ary_new_from_node_args(VALUE ast_value, long n, ...)
 {
     va_list ar;
     VALUE ary;
@@ -309,39 +327,57 @@ rb_ary_new_from_node_args(rb_ast_t *ast, long n, ...)
     for (i=0; i<n; i++) {
         NODE *node;
         node = va_arg(ar, NODE *);
-        rb_ary_push(ary, NEW_CHILD(ast, node));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node));
     }
     va_end(ar);
     return ary;
 }
 
 static VALUE
-dump_block(rb_ast_t *ast, NODE *node)
+dump_block(VALUE ast_value, const struct RNode_BLOCK *node)
 {
     VALUE ary = rb_ary_new();
     do {
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_head));
     } while (node->nd_next &&
-        nd_type(node->nd_next) == NODE_BLOCK &&
-        (node = node->nd_next, 1));
+        nd_type_p(node->nd_next, NODE_BLOCK) &&
+        (node = RNODE_BLOCK(node->nd_next), 1));
     if (node->nd_next) {
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_next));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_next));
     }
 
     return ary;
 }
 
 static VALUE
-dump_array(rb_ast_t *ast, NODE *node)
+dump_array(VALUE ast_value, const struct RNode_LIST *node)
 {
     VALUE ary = rb_ary_new();
-    rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+    rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_head));
 
-    while (node->nd_next && nd_type(node->nd_next) == NODE_LIST) {
-        node = node->nd_next;
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+    while (node->nd_next && nd_type_p(node->nd_next, NODE_LIST)) {
+        node = RNODE_LIST(node->nd_next);
+        rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_head));
+    }
+    rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_next));
+
+    return ary;
+}
+
+static VALUE
+dump_parser_array(VALUE ast_value, rb_parser_ary_t *p_ary)
+{
+    VALUE ary;
+
+    if (p_ary->data_type != PARSER_ARY_DATA_NODE) {
+        rb_bug("unexpected rb_parser_ary_data_type: %d", p_ary->data_type);
+    }
+
+    ary = rb_ary_new();
+
+    for (long i = 0; i < p_ary->len; i++) {
+        rb_ary_push(ary, NEW_CHILD(ast_value, p_ary->data[i]));
     }
-    rb_ary_push(ary, NEW_CHILD(ast, node->nd_next));
 
     return ary;
 }
@@ -355,311 +391,362 @@ var_name(ID id)
 }
 
 static VALUE
-node_children(rb_ast_t *ast, NODE *node)
+no_name_rest(void)
 {
-    char name[DECIMAL_SIZE_OF_BITS(sizeof(long) * CHAR_BIT) + 2]; /* including '$' */
+    ID rest;
+    CONST_ID(rest, "NODE_SPECIAL_NO_NAME_REST");
+    return ID2SYM(rest);
+}
+
+static VALUE
+rest_arg(VALUE ast_value, const NODE *rest_arg)
+{
+    return NODE_NAMED_REST_P(rest_arg) ? NEW_CHILD(ast_value, rest_arg) : no_name_rest();
+}
+
+static ID
+node_colon_name(const NODE *node)
+{
+    switch (nd_type(node)) {
+      case NODE_COLON2:
+        return RNODE_COLON2(node)->nd_mid;
+      case NODE_COLON3:
+        return RNODE_COLON3(node)->nd_mid;
+      default:
+        rb_bug("unexpected node: %s", ruby_node_name(nd_type(node)));
+    }
+}
+
+static VALUE
+node_children(VALUE ast_value, const NODE *node)
+{
+    char name[sizeof("$") + DECIMAL_SIZE_OF(long)];
 
     enum node_type type = nd_type(node);
     switch (type) {
       case NODE_BLOCK:
-        return dump_block(ast, node);
+        return dump_block(ast_value, RNODE_BLOCK(node));
       case NODE_IF:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_cond, node->nd_body, node->nd_else);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_IF(node)->nd_cond, RNODE_IF(node)->nd_body, RNODE_IF(node)->nd_else);
       case NODE_UNLESS:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_cond, node->nd_body, node->nd_else);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_UNLESS(node)->nd_cond, RNODE_UNLESS(node)->nd_body, RNODE_UNLESS(node)->nd_else);
       case NODE_CASE:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_CASE(node)->nd_head, RNODE_CASE(node)->nd_body);
       case NODE_CASE2:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_CASE2(node)->nd_head, RNODE_CASE2(node)->nd_body);
       case NODE_CASE3:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_CASE3(node)->nd_head, RNODE_CASE3(node)->nd_body);
       case NODE_WHEN:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_head, node->nd_body, node->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_WHEN(node)->nd_head, RNODE_WHEN(node)->nd_body, RNODE_WHEN(node)->nd_next);
       case NODE_IN:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_head, node->nd_body, node->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_IN(node)->nd_head, RNODE_IN(node)->nd_body, RNODE_IN(node)->nd_next);
       case NODE_WHILE:
-        goto loop;
       case NODE_UNTIL:
-      loop:
-        return rb_ary_push(rb_ary_new_from_node_args(ast, 2, node->nd_cond, node->nd_body),
-                           (node->nd_state ? Qtrue : Qfalse));
+        return rb_ary_push(rb_ary_new_from_node_args(ast_value, 2, RNODE_WHILE(node)->nd_cond, RNODE_WHILE(node)->nd_body),
+                           RBOOL(RNODE_WHILE(node)->nd_state));
       case NODE_ITER:
       case NODE_FOR:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_iter, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ITER(node)->nd_iter, RNODE_ITER(node)->nd_body);
       case NODE_FOR_MASGN:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_var);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_FOR_MASGN(node)->nd_var);
       case NODE_BREAK:
-        goto jump;
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_BREAK(node)->nd_stts);
       case NODE_NEXT:
-        goto jump;
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_NEXT(node)->nd_stts);
       case NODE_RETURN:
-      jump:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_stts);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_RETURN(node)->nd_stts);
       case NODE_REDO:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_RETRY:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_BEGIN:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_BEGIN(node)->nd_body);
       case NODE_RESCUE:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_head, node->nd_resq, node->nd_else);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_RESCUE(node)->nd_head, RNODE_RESCUE(node)->nd_resq, RNODE_RESCUE(node)->nd_else);
       case NODE_RESBODY:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_args, node->nd_body, node->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 4, RNODE_RESBODY(node)->nd_args, RNODE_RESBODY(node)->nd_exc_var, RNODE_RESBODY(node)->nd_body, RNODE_RESBODY(node)->nd_next);
       case NODE_ENSURE:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_ensr);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ENSURE(node)->nd_head, RNODE_ENSURE(node)->nd_ensr);
       case NODE_AND:
-        goto andor;
       case NODE_OR:
-      andor:
         {
             VALUE ary = rb_ary_new();
 
             while (1) {
-                rb_ary_push(ary, NEW_CHILD(ast, node->nd_1st));
-                if (!node->nd_2nd || nd_type(node->nd_2nd) != (int)type)
+                rb_ary_push(ary, NEW_CHILD(ast_value, RNODE_AND(node)->nd_1st));
+                if (!RNODE_AND(node)->nd_2nd || !nd_type_p(RNODE_AND(node)->nd_2nd, type))
                     break;
-                node = node->nd_2nd;
+                node = RNODE_AND(node)->nd_2nd;
             }
-            rb_ary_push(ary, NEW_CHILD(ast, node->nd_2nd));
+            rb_ary_push(ary, NEW_CHILD(ast_value, RNODE_AND(node)->nd_2nd));
             return ary;
         }
       case NODE_MASGN:
-        if (NODE_NAMED_REST_P(node->nd_args)) {
-            return rb_ary_new_from_node_args(ast, 3, node->nd_value, node->nd_head, node->nd_args);
+        if (NODE_NAMED_REST_P(RNODE_MASGN(node)->nd_args)) {
+            return rb_ary_new_from_node_args(ast_value, 3, RNODE_MASGN(node)->nd_value, RNODE_MASGN(node)->nd_head, RNODE_MASGN(node)->nd_args);
         }
         else {
-            return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_value),
-                                        NEW_CHILD(ast, node->nd_head),
-                                        ID2SYM(rb_intern("NODE_SPECIAL_NO_NAME_REST")));
+            return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_MASGN(node)->nd_value),
+                                        NEW_CHILD(ast_value, RNODE_MASGN(node)->nd_head),
+                                        no_name_rest());
         }
       case NODE_LASGN:
-        goto asgn;
+        if (NODE_REQUIRED_KEYWORD_P(RNODE_LASGN(node)->nd_value)) {
+            return rb_ary_new_from_args(2, var_name(RNODE_LASGN(node)->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
+        }
+        return rb_ary_new_from_args(2, var_name(RNODE_LASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_LASGN(node)->nd_value));
       case NODE_DASGN:
-        goto asgn;
-      case NODE_DASGN_CURR:
-        goto asgn;
+        if (NODE_REQUIRED_KEYWORD_P(RNODE_DASGN(node)->nd_value)) {
+            return rb_ary_new_from_args(2, var_name(RNODE_DASGN(node)->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
+        }
+        return rb_ary_new_from_args(2, var_name(RNODE_DASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_DASGN(node)->nd_value));
       case NODE_IASGN:
-        goto asgn;
+        return rb_ary_new_from_args(2, var_name(RNODE_IASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_IASGN(node)->nd_value));
       case NODE_CVASGN:
-      asgn:
-        if (NODE_REQUIRED_KEYWORD_P(node)) {
-            return rb_ary_new_from_args(2, var_name(node->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
-        }
-        return rb_ary_new_from_args(2, var_name(node->nd_vid), NEW_CHILD(ast, node->nd_value));
+        return rb_ary_new_from_args(2, var_name(RNODE_CVASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_CVASGN(node)->nd_value));
       case NODE_GASGN:
-        goto asgn;
+        return rb_ary_new_from_args(2, var_name(RNODE_GASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_GASGN(node)->nd_value));
       case NODE_CDECL:
-        if (node->nd_vid) {
-            return rb_ary_new_from_args(2, ID2SYM(node->nd_vid), NEW_CHILD(ast, node->nd_value));
+        if (RNODE_CDECL(node)->nd_vid) {
+            return rb_ary_new_from_args(2, ID2SYM(RNODE_CDECL(node)->nd_vid), NEW_CHILD(ast_value, RNODE_CDECL(node)->nd_value));
         }
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_else), ID2SYM(node->nd_else->nd_mid), NEW_CHILD(ast, node->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_CDECL(node)->nd_else), ID2SYM(node_colon_name(RNODE_CDECL(node)->nd_else)), NEW_CHILD(ast_value, RNODE_CDECL(node)->nd_value));
       case NODE_OP_ASGN1:
-        return rb_ary_new_from_args(4, NEW_CHILD(ast, node->nd_recv),
-                                    ID2SYM(node->nd_mid),
-                                    NEW_CHILD(ast, node->nd_args->nd_head),
-                                    NEW_CHILD(ast, node->nd_args->nd_body));
+        return rb_ary_new_from_args(4, NEW_CHILD(ast_value, RNODE_OP_ASGN1(node)->nd_recv),
+                                    ID2SYM(RNODE_OP_ASGN1(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN1(node)->nd_index),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN1(node)->nd_rvalue));
       case NODE_OP_ASGN2:
-        return rb_ary_new_from_args(4, NEW_CHILD(ast, node->nd_recv),
-                                    node->nd_next->nd_aid ? Qtrue : Qfalse,
-                                    ID2SYM(node->nd_next->nd_vid),
-                                    NEW_CHILD(ast, node->nd_value));
+        return rb_ary_new_from_args(5, NEW_CHILD(ast_value, RNODE_OP_ASGN2(node)->nd_recv),
+                                    RBOOL(RNODE_OP_ASGN2(node)->nd_aid),
+                                    ID2SYM(RNODE_OP_ASGN2(node)->nd_vid),
+                                    ID2SYM(RNODE_OP_ASGN2(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN2(node)->nd_value));
       case NODE_OP_ASGN_AND:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head), ID2SYM(idANDOP),
-                                    NEW_CHILD(ast, node->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OP_ASGN_AND(node)->nd_head), ID2SYM(idANDOP),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN_AND(node)->nd_value));
       case NODE_OP_ASGN_OR:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head), ID2SYM(idOROP),
-                                    NEW_CHILD(ast, node->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OP_ASGN_OR(node)->nd_head), ID2SYM(idOROP),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN_OR(node)->nd_value));
       case NODE_OP_CDECL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head),
-                                    ID2SYM(node->nd_aid),
-                                    NEW_CHILD(ast, node->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OP_CDECL(node)->nd_head),
+                                    ID2SYM(RNODE_OP_CDECL(node)->nd_aid),
+                                    NEW_CHILD(ast_value, RNODE_OP_CDECL(node)->nd_value));
       case NODE_CALL:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_CALL(node)->nd_recv),
+                                    ID2SYM(RNODE_CALL(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_CALL(node)->nd_args));
       case NODE_OPCALL:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OPCALL(node)->nd_recv),
+                                    ID2SYM(RNODE_OPCALL(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_OPCALL(node)->nd_args));
       case NODE_QCALL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv),
-                                    ID2SYM(node->nd_mid),
-                                    NEW_CHILD(ast, node->nd_args));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_QCALL(node)->nd_recv),
+                                    ID2SYM(RNODE_QCALL(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_QCALL(node)->nd_args));
       case NODE_FCALL:
-        return rb_ary_new_from_args(2, ID2SYM(node->nd_mid),
-                                    NEW_CHILD(ast, node->nd_args));
+        return rb_ary_new_from_args(2, ID2SYM(RNODE_FCALL(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_FCALL(node)->nd_args));
       case NODE_VCALL:
-        return rb_ary_new_from_args(1, ID2SYM(node->nd_mid));
-      case NODE_METHREF:
-        return rb_ary_new_from_args(2, NEW_CHILD(ast, node->nd_recv),
-                                    ID2SYM(node->nd_mid));
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_VCALL(node)->nd_mid));
       case NODE_SUPER:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_args);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_SUPER(node)->nd_args);
       case NODE_ZSUPER:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_LIST:
-        goto ary;
-      case NODE_VALUES:
-      ary:
-        return dump_array(ast, node);
+        return dump_array(ast_value, RNODE_LIST(node));
       case NODE_ZLIST:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_HASH:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_HASH(node)->nd_head);
       case NODE_YIELD:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_YIELD(node)->nd_head);
       case NODE_LVAR:
+        return rb_ary_new_from_args(1, var_name(RNODE_LVAR(node)->nd_vid));
       case NODE_DVAR:
-        return rb_ary_new_from_args(1, var_name(node->nd_vid));
+        return rb_ary_new_from_args(1, var_name(RNODE_DVAR(node)->nd_vid));
       case NODE_IVAR:
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_IVAR(node)->nd_vid));
       case NODE_CONST:
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_CONST(node)->nd_vid));
       case NODE_CVAR:
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_CVAR(node)->nd_vid));
       case NODE_GVAR:
-        return rb_ary_new_from_args(1, ID2SYM(node->nd_vid));
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_GVAR(node)->nd_vid));
       case NODE_NTH_REF:
-        snprintf(name, sizeof(name), "$%ld", node->nd_nth);
+        snprintf(name, sizeof(name), "$%ld", RNODE_NTH_REF(node)->nd_nth);
         return rb_ary_new_from_args(1, ID2SYM(rb_intern(name)));
       case NODE_BACK_REF:
         name[0] = '$';
-        name[1] = (char)node->nd_nth;
+        name[1] = (char)RNODE_BACK_REF(node)->nd_nth;
         name[2] = '\0';
         return rb_ary_new_from_args(1, ID2SYM(rb_intern(name)));
       case NODE_MATCH:
-        goto lit;
+        return rb_ary_new_from_args(1, rb_node_regx_string_val(node));
       case NODE_MATCH2:
-        if (node->nd_args) {
-            return rb_ary_new_from_node_args(ast, 3, node->nd_recv, node->nd_value, node->nd_args);
+        if (RNODE_MATCH2(node)->nd_args) {
+            return rb_ary_new_from_node_args(ast_value, 3, RNODE_MATCH2(node)->nd_recv, RNODE_MATCH2(node)->nd_value, RNODE_MATCH2(node)->nd_args);
         }
-        return rb_ary_new_from_node_args(ast, 2, node->nd_recv, node->nd_value);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_MATCH2(node)->nd_recv, RNODE_MATCH2(node)->nd_value);
       case NODE_MATCH3:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_recv, node->nd_value);
-      case NODE_LIT:
-        goto lit;
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_MATCH3(node)->nd_recv, RNODE_MATCH3(node)->nd_value);
       case NODE_STR:
-        goto lit;
       case NODE_XSTR:
-      lit:
-        return rb_ary_new_from_args(1, node->nd_lit);
+        return rb_ary_new_from_args(1, rb_node_str_string_val(node));
+      case NODE_INTEGER:
+        return rb_ary_new_from_args(1, rb_node_integer_literal_val(node));
+      case NODE_FLOAT:
+        return rb_ary_new_from_args(1, rb_node_float_literal_val(node));
+      case NODE_RATIONAL:
+        return rb_ary_new_from_args(1, rb_node_rational_literal_val(node));
+      case NODE_IMAGINARY:
+        return rb_ary_new_from_args(1, rb_node_imaginary_literal_val(node));
+      case NODE_REGX:
+        return rb_ary_new_from_args(1, rb_node_regx_string_val(node));
       case NODE_ONCE:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_ONCE(node)->nd_body);
       case NODE_DSTR:
-        goto dlit;
       case NODE_DXSTR:
-        goto dlit;
       case NODE_DREGX:
-        goto dlit;
       case NODE_DSYM:
-      dlit:
-        return rb_ary_new_from_args(3, node->nd_lit,
-                                    NEW_CHILD(ast, node->nd_next->nd_head),
-                                    NEW_CHILD(ast, node->nd_next->nd_next));
+        {
+            struct RNode_LIST *n = RNODE_DSTR(node)->nd_next;
+            VALUE head = Qnil, next = Qnil;
+            if (n) {
+                head = NEW_CHILD(ast_value, n->nd_head);
+                next = NEW_CHILD(ast_value, n->nd_next);
+            }
+            return rb_ary_new_from_args(3, rb_node_dstr_string_val(node), head, next);
+        }
+      case NODE_SYM:
+        return rb_ary_new_from_args(1, rb_node_sym_string_val(node));
       case NODE_EVSTR:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_EVSTR(node)->nd_body);
       case NODE_ARGSCAT:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ARGSCAT(node)->nd_head, RNODE_ARGSCAT(node)->nd_body);
       case NODE_ARGSPUSH:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ARGSPUSH(node)->nd_head, RNODE_ARGSPUSH(node)->nd_body);
       case NODE_SPLAT:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_SPLAT(node)->nd_head);
       case NODE_BLOCK_PASS:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_BLOCK_PASS(node)->nd_head, RNODE_BLOCK_PASS(node)->nd_body);
       case NODE_DEFN:
-        return rb_ary_new_from_args(2, ID2SYM(node->nd_mid), NEW_CHILD(ast, node->nd_defn));
+        return rb_ary_new_from_args(2, ID2SYM(RNODE_DEFN(node)->nd_mid), NEW_CHILD(ast_value, RNODE_DEFN(node)->nd_defn));
       case NODE_DEFS:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv), ID2SYM(node->nd_mid), NEW_CHILD(ast, node->nd_defn));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_DEFS(node)->nd_recv), ID2SYM(RNODE_DEFS(node)->nd_mid), NEW_CHILD(ast_value, RNODE_DEFS(node)->nd_defn));
       case NODE_ALIAS:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_1st, node->nd_2nd);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ALIAS(node)->nd_1st, RNODE_ALIAS(node)->nd_2nd);
       case NODE_VALIAS:
-        return rb_ary_new_from_args(2, ID2SYM(node->nd_alias), ID2SYM(node->nd_orig));
+        return rb_ary_new_from_args(2, ID2SYM(RNODE_VALIAS(node)->nd_alias), ID2SYM(RNODE_VALIAS(node)->nd_orig));
       case NODE_UNDEF:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_undef);
+        return rb_ary_new_from_args(1, dump_parser_array(ast_value, RNODE_UNDEF(node)->nd_undefs));
       case NODE_CLASS:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_cpath, node->nd_super, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_CLASS(node)->nd_cpath, RNODE_CLASS(node)->nd_super, RNODE_CLASS(node)->nd_body);
       case NODE_MODULE:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_cpath, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_MODULE(node)->nd_cpath, RNODE_MODULE(node)->nd_body);
       case NODE_SCLASS:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_recv, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_SCLASS(node)->nd_recv, RNODE_SCLASS(node)->nd_body);
       case NODE_COLON2:
-        return rb_ary_new_from_args(2, NEW_CHILD(ast, node->nd_head), ID2SYM(node->nd_mid));
+        return rb_ary_new_from_args(2, NEW_CHILD(ast_value, RNODE_COLON2(node)->nd_head), ID2SYM(RNODE_COLON2(node)->nd_mid));
       case NODE_COLON3:
-        return rb_ary_new_from_args(1, ID2SYM(node->nd_mid));
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_COLON3(node)->nd_mid));
       case NODE_DOT2:
-        goto dot;
       case NODE_DOT3:
-        goto dot;
       case NODE_FLIP2:
-        goto dot;
       case NODE_FLIP3:
-      dot:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_beg, node->nd_end);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_DOT2(node)->nd_beg, RNODE_DOT2(node)->nd_end);
       case NODE_SELF:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_NIL:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_TRUE:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_FALSE:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_ERRINFO:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_DEFINED:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_DEFINED(node)->nd_head);
       case NODE_POSTEXE:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_POSTEXE(node)->nd_body);
       case NODE_ATTRASGN:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv), ID2SYM(node->nd_mid), NEW_CHILD(ast, node->nd_args));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_ATTRASGN(node)->nd_recv), ID2SYM(RNODE_ATTRASGN(node)->nd_mid), NEW_CHILD(ast_value, RNODE_ATTRASGN(node)->nd_args));
       case NODE_LAMBDA:
-        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_LAMBDA(node)->nd_body);
       case NODE_OPT_ARG:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_body, node->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_OPT_ARG(node)->nd_body, RNODE_OPT_ARG(node)->nd_next);
       case NODE_KW_ARG:
-        return rb_ary_new_from_node_args(ast, 2, node->nd_body, node->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_KW_ARG(node)->nd_body, RNODE_KW_ARG(node)->nd_next);
       case NODE_POSTARG:
-        if (NODE_NAMED_REST_P(node->nd_1st)) {
-            return rb_ary_new_from_node_args(ast, 2, node->nd_1st, node->nd_2nd);
+        if (NODE_NAMED_REST_P(RNODE_POSTARG(node)->nd_1st)) {
+            return rb_ary_new_from_node_args(ast_value, 2, RNODE_POSTARG(node)->nd_1st, RNODE_POSTARG(node)->nd_2nd);
         }
-        return rb_ary_new_from_args(2, ID2SYM(rb_intern("NODE_SPECIAL_NO_NAME_REST")),
-                                    NEW_CHILD(ast, node->nd_2nd));
+        return rb_ary_new_from_args(2, no_name_rest(),
+                                    NEW_CHILD(ast_value, RNODE_POSTARG(node)->nd_2nd));
       case NODE_ARGS:
         {
-            struct rb_args_info *ainfo = node->nd_ainfo;
+            struct rb_args_info *ainfo = &RNODE_ARGS(node)->nd_ainfo;
             return rb_ary_new_from_args(10,
                                         INT2NUM(ainfo->pre_args_num),
-                                        NEW_CHILD(ast, ainfo->pre_init),
-                                        NEW_CHILD(ast, ainfo->opt_args),
+                                        NEW_CHILD(ast_value, ainfo->pre_init),
+                                        NEW_CHILD(ast_value, (NODE *)ainfo->opt_args),
                                         var_name(ainfo->first_post_arg),
                                         INT2NUM(ainfo->post_args_num),
-                                        NEW_CHILD(ast, ainfo->post_init),
-                                        var_name(ainfo->rest_arg),
-                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast, ainfo->kw_args)),
-                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast, ainfo->kw_rest_arg)),
-                                        var_name(ainfo->block_arg));
+                                        NEW_CHILD(ast_value, ainfo->post_init),
+                                        (ainfo->rest_arg == NODE_SPECIAL_EXCESSIVE_COMMA
+                                            ? ID2SYM(rb_intern("NODE_SPECIAL_EXCESSIVE_COMMA"))
+                                            : var_name(ainfo->rest_arg)),
+                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast_value, (NODE *)ainfo->kw_args)),
+                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast_value, ainfo->kw_rest_arg)),
+                                        (ainfo->no_blockarg ? Qfalse : var_name(ainfo->block_arg)));
         }
       case NODE_SCOPE:
         {
-            ID *tbl = node->nd_tbl;
-            int i, size = tbl ? (int)*tbl++ : 0;
+            rb_ast_id_table_t *tbl = RNODE_SCOPE(node)->nd_tbl;
+            int i, size = tbl ? tbl->size : 0;
             VALUE locals = rb_ary_new_capa(size);
             for (i = 0; i < size; i++) {
-                rb_ary_push(locals, var_name(tbl[i]));
+                rb_ary_push(locals, var_name(tbl->ids[i]));
             }
-            return rb_ary_new_from_args(3, locals, NEW_CHILD(ast, node->nd_args), NEW_CHILD(ast, node->nd_body));
+            return rb_ary_new_from_args(3, locals, NEW_CHILD(ast_value, (NODE *)RNODE_SCOPE(node)->nd_args), NEW_CHILD(ast_value, RNODE_SCOPE(node)->nd_body));
         }
       case NODE_ARYPTN:
         {
-            struct rb_ary_pattern_info *apinfo = node->nd_apinfo;
-            VALUE rest = NODE_NAMED_REST_P(apinfo->rest_arg) ? NEW_CHILD(ast, apinfo->rest_arg) :
-                                                               ID2SYM(rb_intern("NODE_SPECIAL_NO_NAME_REST"));
+            VALUE rest = rest_arg(ast_value, RNODE_ARYPTN(node)->rest_arg);
             return rb_ary_new_from_args(4,
-                                        NEW_CHILD(ast, node->nd_pconst),
-                                        NEW_CHILD(ast, apinfo->pre_args),
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->pre_args),
                                         rest,
-                                        NEW_CHILD(ast, apinfo->post_args));
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->post_args));
+        }
+      case NODE_FNDPTN:
+        {
+            VALUE pre_rest = rest_arg(ast_value, RNODE_FNDPTN(node)->pre_rest_arg);
+            VALUE post_rest = rest_arg(ast_value, RNODE_FNDPTN(node)->post_rest_arg);
+            return rb_ary_new_from_args(4,
+                                        NEW_CHILD(ast_value, RNODE_FNDPTN(node)->nd_pconst),
+                                        pre_rest,
+                                        NEW_CHILD(ast_value, RNODE_FNDPTN(node)->args),
+                                        post_rest);
         }
       case NODE_HSHPTN:
         {
-            VALUE kwrest = node->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD ? ID2SYM(rb_intern("NODE_SPECIAL_NO_REST_KEYWORD")) :
-                                                                                 NEW_CHILD(ast, node->nd_pkwrestarg);
+            VALUE kwrest = RNODE_HSHPTN(node)->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD ? ID2SYM(rb_intern("NODE_SPECIAL_NO_REST_KEYWORD")) :
+                                                                                 NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pkwrestarg);
 
             return rb_ary_new_from_args(3,
-                                        NEW_CHILD(ast, node->nd_pconst),
-                                        NEW_CHILD(ast, node->nd_pkwargs),
+                                        NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pkwargs),
                                         kwrest);
         }
+      case NODE_LINE:
+        return rb_ary_new_from_args(1, rb_node_line_lineno_val(node));
+      case NODE_FILE:
+        return rb_ary_new_from_args(1, rb_node_file_path_val(node));
+      case NODE_ENCODING:
+        return rb_ary_new_from_args(1, rb_node_encoding_val(node));
+      case NODE_ERROR:
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_ARGS_AUX:
       case NODE_LAST:
         break;
@@ -668,32 +755,260 @@ node_children(rb_ast_t *ast, NODE *node)
     rb_bug("node_children: unknown node: %s", ruby_node_name(type));
 }
 
-/*
- *  call-seq:
- *     node.children -> array
- *
- *  Returns AST nodes under this one.  Each kind of node
- *  has different children, depending on what kind of node it is.
- *
- *  The returned array may contain other nodes or <code>nil</code>.
- */
 static VALUE
-rb_ast_node_children(VALUE self)
+ast_node_children(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return node_children(data->ast_value, data->node);
+}
+
+static int
+null_loc_p(rb_code_location_t *loc)
+{
+    return (loc->beg_pos.lineno == 0 && loc->beg_pos.column == -1 && loc->end_pos.lineno == 0 && loc->end_pos.column == -1);
+}
+
+static VALUE
+location_new(rb_code_location_t *loc)
+{
+    VALUE obj;
+    struct ASTLocationData *data;
+
+    if (null_loc_p(loc)) return Qnil;
+
+    obj = TypedData_Make_Struct(rb_cLocation, struct ASTLocationData, &rb_location_type, data);
+    data->first_lineno = loc->beg_pos.lineno;
+    data->first_column = loc->beg_pos.column;
+    data->last_lineno = loc->end_pos.lineno;
+    data->last_column = loc->end_pos.column;
+
+    return obj;
+}
+
+static VALUE
+node_locations(VALUE ast_value, const NODE *node)
+{
+    enum node_type type = nd_type(node);
+    switch (type) {
+      case NODE_ALIAS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_ALIAS(node)->keyword_loc));
+      case NODE_AND:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_AND(node)->operator_loc));
+      case NODE_BLOCK_PASS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_BLOCK_PASS(node)->operator_loc));
+      case NODE_BREAK:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_BREAK(node)->keyword_loc));
+      case NODE_CASE:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CASE(node)->case_keyword_loc),
+                                    location_new(&RNODE_CASE(node)->end_keyword_loc));
+      case NODE_CASE2:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CASE2(node)->case_keyword_loc),
+                                    location_new(&RNODE_CASE2(node)->end_keyword_loc));
+      case NODE_CASE3:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CASE3(node)->case_keyword_loc),
+                                    location_new(&RNODE_CASE3(node)->end_keyword_loc));
+      case NODE_CLASS:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CLASS(node)->class_keyword_loc),
+                                    location_new(&RNODE_CLASS(node)->inheritance_operator_loc),
+                                    location_new(&RNODE_CLASS(node)->end_keyword_loc));
+      case NODE_COLON2:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_COLON2(node)->delimiter_loc),
+                                    location_new(&RNODE_COLON2(node)->name_loc));
+      case NODE_COLON3:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_COLON3(node)->delimiter_loc),
+                                    location_new(&RNODE_COLON3(node)->name_loc));
+      case NODE_DEFINED:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_DEFINED(node)->keyword_loc));
+      case NODE_DOT2:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_DOT2(node)->operator_loc));
+      case NODE_DOT3:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_DOT3(node)->operator_loc));
+      case NODE_EVSTR:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_EVSTR(node)->opening_loc),
+                                    location_new(&RNODE_EVSTR(node)->closing_loc));
+      case NODE_FLIP2:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_FLIP2(node)->operator_loc));
+      case NODE_FLIP3:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_FLIP3(node)->operator_loc));
+      case NODE_FOR:
+        return rb_ary_new_from_args(5,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_FOR(node)->for_keyword_loc),
+                                    location_new(&RNODE_FOR(node)->in_keyword_loc),
+                                    location_new(&RNODE_FOR(node)->do_keyword_loc),
+                                    location_new(&RNODE_FOR(node)->end_keyword_loc));
+      case NODE_LAMBDA:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_LAMBDA(node)->operator_loc),
+                                    location_new(&RNODE_LAMBDA(node)->opening_loc),
+                                    location_new(&RNODE_LAMBDA(node)->closing_loc));
+      case NODE_IF:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_IF(node)->if_keyword_loc),
+                                    location_new(&RNODE_IF(node)->then_keyword_loc),
+                                    location_new(&RNODE_IF(node)->end_keyword_loc));
+      case NODE_IN:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_IN(node)->in_keyword_loc),
+                                    location_new(&RNODE_IN(node)->then_keyword_loc),
+                                    location_new(&RNODE_IN(node)->operator_loc));
+      case NODE_MODULE:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_MODULE(node)->module_keyword_loc),
+                                    location_new(&RNODE_MODULE(node)->end_keyword_loc));
+      case NODE_NEXT:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_NEXT(node)->keyword_loc));
+      case NODE_OR:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_OR(node)->operator_loc));
+      case NODE_OP_ASGN1:
+        return rb_ary_new_from_args(5,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_OP_ASGN1(node)->call_operator_loc),
+                                    location_new(&RNODE_OP_ASGN1(node)->opening_loc),
+                                    location_new(&RNODE_OP_ASGN1(node)->closing_loc),
+                                    location_new(&RNODE_OP_ASGN1(node)->binary_operator_loc));
+      case NODE_OP_ASGN2:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_OP_ASGN2(node)->call_operator_loc),
+                                    location_new(&RNODE_OP_ASGN2(node)->message_loc),
+                                    location_new(&RNODE_OP_ASGN2(node)->binary_operator_loc));
+      case NODE_POSTEXE:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_POSTEXE(node)->keyword_loc),
+                                    location_new(&RNODE_POSTEXE(node)->opening_loc),
+                                    location_new(&RNODE_POSTEXE(node)->closing_loc));
+      case NODE_REDO:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_REDO(node)->keyword_loc));
+      case NODE_REGX:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_REGX(node)->opening_loc),
+                                    location_new(&RNODE_REGX(node)->content_loc),
+                                    location_new(&RNODE_REGX(node)->closing_loc));
+      case NODE_RETURN:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_RETURN(node)->keyword_loc));
+
+      case NODE_SCLASS:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_SCLASS(node)->class_keyword_loc),
+                                    location_new(&RNODE_SCLASS(node)->operator_loc),
+                                    location_new(&RNODE_SCLASS(node)->end_keyword_loc));
+
+      case NODE_SPLAT:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_SPLAT(node)->operator_loc));
+      case NODE_SUPER:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_SUPER(node)->keyword_loc),
+                                    location_new(&RNODE_SUPER(node)->lparen_loc),
+                                    location_new(&RNODE_SUPER(node)->rparen_loc));
+      case NODE_UNDEF:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_UNDEF(node)->keyword_loc));
+      case NODE_UNLESS:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_UNLESS(node)->keyword_loc),
+                                    location_new(&RNODE_UNLESS(node)->then_keyword_loc),
+                                    location_new(&RNODE_UNLESS(node)->end_keyword_loc));
+      case NODE_VALIAS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_VALIAS(node)->keyword_loc));
+      case NODE_WHEN:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_WHEN(node)->keyword_loc),
+                                    location_new(&RNODE_WHEN(node)->then_keyword_loc));
+      case NODE_WHILE:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_WHILE(node)->keyword_loc),
+                                    location_new(&RNODE_WHILE(node)->closing_loc));
+      case NODE_UNTIL:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_UNTIL(node)->keyword_loc),
+                                    location_new(&RNODE_UNTIL(node)->closing_loc));
+      case NODE_YIELD:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_YIELD(node)->keyword_loc),
+                                    location_new(&RNODE_YIELD(node)->lparen_loc),
+                                    location_new(&RNODE_YIELD(node)->rparen_loc));
+      case NODE_ARGS_AUX:
+      case NODE_LAST:
+        break;
+      default:
+        return rb_ary_new_from_args(1, location_new(nd_code_loc(node)));
+    }
+
+    rb_bug("node_locations: unknown node: %s", ruby_node_name(type));
+}
+
+static VALUE
+ast_node_locations(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
 
-    return node_children(data->ast, data->node);
+    return node_locations(data->ast_value, data->node);
 }
 
-/*
- *  call-seq:
- *     node.first_lineno -> integer
- *
- *  The line number in the source code where this AST's text began.
- */
 static VALUE
-rb_ast_node_first_lineno(VALUE self)
+ast_node_first_lineno(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
@@ -701,14 +1016,8 @@ rb_ast_node_first_lineno(VALUE self)
     return INT2NUM(nd_first_lineno(data->node));
 }
 
-/*
- *  call-seq:
- *     node.first_column -> integer
- *
- *  The column number in the source code where this AST's text began.
- */
 static VALUE
-rb_ast_node_first_column(VALUE self)
+ast_node_first_column(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
@@ -716,14 +1025,8 @@ rb_ast_node_first_column(VALUE self)
     return INT2NUM(nd_first_column(data->node));
 }
 
-/*
- *  call-seq:
- *     node.last_lineno -> integer
- *
- *  The line number in the source code where this AST's text ended.
- */
 static VALUE
-rb_ast_node_last_lineno(VALUE self)
+ast_node_last_lineno(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
@@ -731,14 +1034,8 @@ rb_ast_node_last_lineno(VALUE self)
     return INT2NUM(nd_last_lineno(data->node));
 }
 
-/*
- *  call-seq:
- *     node.last_column -> integer
- *
- *  The column number in the source code where this AST's text ended.
- */
 static VALUE
-rb_ast_node_last_column(VALUE self)
+ast_node_last_column(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
@@ -746,14 +1043,44 @@ rb_ast_node_last_column(VALUE self)
     return INT2NUM(nd_last_column(data->node));
 }
 
-/*
- *  call-seq:
- *     node.inspect -> string
- *
- *  Returns debugging information about this node as a string.
- */
 static VALUE
-rb_ast_node_inspect(VALUE self)
+ast_node_all_tokens(rb_execution_context_t *ec, VALUE self)
+{
+    long i;
+    struct ASTNodeData *data;
+    rb_ast_t *ast;
+    rb_parser_ary_t *parser_tokens;
+    rb_parser_ast_token_t *parser_token;
+    VALUE str, loc, token, all_tokens;
+
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+    ast = rb_ruby_ast_data_get(data->ast_value);
+
+    parser_tokens = ast->node_buffer->tokens;
+    if (parser_tokens == NULL) {
+        return Qnil;
+    }
+
+    all_tokens = rb_ary_new2(parser_tokens->len);
+    for (i = 0; i < parser_tokens->len; i++) {
+        parser_token = parser_tokens->data[i];
+        str = rb_str_new(parser_token->str->ptr, parser_token->str->len);
+        loc = rb_ary_new_from_args(4,
+            INT2FIX(parser_token->loc.beg_pos.lineno),
+            INT2FIX(parser_token->loc.beg_pos.column),
+            INT2FIX(parser_token->loc.end_pos.lineno),
+            INT2FIX(parser_token->loc.end_pos.column)
+        );
+        token = rb_ary_new_from_args(4, INT2FIX(parser_token->id), ID2SYM(rb_intern(parser_token->type_name)), str, loc);
+        rb_ary_push(all_tokens, token);
+    }
+    rb_ary_freeze(all_tokens);
+
+    return all_tokens;
+}
+
+static VALUE
+ast_node_inspect(rb_execution_context_t *ec, VALUE self)
 {
     VALUE str;
     VALUE cname;
@@ -772,35 +1099,80 @@ rb_ast_node_inspect(VALUE self)
     return str;
 }
 
+static VALUE
+ast_node_script_lines(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    rb_ast_t *ast;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+    ast = rb_ruby_ast_data_get(data->ast_value);
+    rb_parser_ary_t *ret = ast->body.script_lines;
+    return rb_parser_build_script_lines_from(ret);
+}
+
+static VALUE
+ast_location_first_lineno(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->first_lineno);
+}
+
+static VALUE
+ast_location_first_column(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->first_column);
+}
+
+static VALUE
+ast_location_last_lineno(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->last_lineno);
+}
+
+static VALUE
+ast_location_last_column(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->last_column);
+}
+
+static VALUE
+ast_location_inspect(rb_execution_context_t *ec, VALUE self)
+{
+    VALUE str;
+    VALUE cname;
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    cname = rb_class_path(rb_obj_class(self));
+    str = rb_str_new2("#<");
+
+    rb_str_append(str, cname);
+    rb_str_catf(str, ":@%d:%d-%d:%d>",
+                data->first_lineno, data->first_column,
+                data->last_lineno, data->last_column);
+
+    return str;
+}
+
+#include "ast.rbinc"
+
 void
 Init_ast(void)
 {
-    /*
-     * AbstractSyntaxTree provides methods to parse Ruby code into
-     * abstract syntax trees. The nodes in the tree
-     * are instances of RubyVM::AbstractSyntaxTree::Node.
-     *
-     * This class is MRI specific as it exposes implementation details
-     * of the MRI abstract syntax tree.
-     */
     rb_mAST = rb_define_module_under(rb_cRubyVM, "AbstractSyntaxTree");
-    /*
-     * RubyVM::AbstractSyntaxTree::Node instances are created by parse methods in
-     * RubyVM::AbstractSyntaxTree.
-     *
-     * This class is MRI specific.
-     */
     rb_cNode = rb_define_class_under(rb_mAST, "Node", rb_cObject);
-
+    rb_cLocation = rb_define_class_under(rb_mAST, "Location", rb_cObject);
     rb_undef_alloc_func(rb_cNode);
-    rb_define_singleton_method(rb_mAST, "parse", rb_ast_s_parse, 1);
-    rb_define_singleton_method(rb_mAST, "parse_file", rb_ast_s_parse_file, 1);
-    rb_define_singleton_method(rb_mAST, "of", rb_ast_s_of, 1);
-    rb_define_method(rb_cNode, "type", rb_ast_node_type, 0);
-    rb_define_method(rb_cNode, "first_lineno", rb_ast_node_first_lineno, 0);
-    rb_define_method(rb_cNode, "first_column", rb_ast_node_first_column, 0);
-    rb_define_method(rb_cNode, "last_lineno", rb_ast_node_last_lineno, 0);
-    rb_define_method(rb_cNode, "last_column", rb_ast_node_last_column, 0);
-    rb_define_method(rb_cNode, "children", rb_ast_node_children, 0);
-    rb_define_method(rb_cNode, "inspect", rb_ast_node_inspect, 0);
+    rb_undef_alloc_func(rb_cLocation);
 }
diff --git a/ast.rb b/ast.rb
new file mode 100644
index 0000000000..6380621780
--- /dev/null
+++ b/ast.rb
@@ -0,0 +1,332 @@
+# for ast.c
+
+# AbstractSyntaxTree provides methods to parse Ruby code into
+# abstract syntax trees. The nodes in the tree
+# are instances of RubyVM::AbstractSyntaxTree::Node.
+#
+# This module is MRI specific as it exposes implementation details
+# of the MRI abstract syntax tree.
+#
+# This module is experimental and its API is not stable, therefore it might
+# change without notice. As examples, the order of children nodes is not
+# guaranteed, the number of children nodes might change, there is no way to
+# access children nodes by name, etc.
+#
+# If you are looking for a stable API or an API working under multiple Ruby
+# implementations, consider using the _prism_ gem, which is the official
+# Ruby API to parse Ruby code.
+#
+module RubyVM::AbstractSyntaxTree
+
+  #  call-seq:
+  #     RubyVM::AbstractSyntaxTree.parse(string, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
+  #
+  #  Parses the given _string_ into an abstract syntax tree,
+  #  returning the root node of that tree.
+  #
+  #    RubyVM::AbstractSyntaxTree.parse("x = 1 + 2")
+  #    # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-1:9>
+  #
+  #  If <tt>keep_script_lines: true</tt> option is provided, the text of the parsed
+  #  source is associated with nodes and is available via Node#script_lines.
+  #
+  #  If <tt>keep_tokens: true</tt> option is provided, Node#tokens are populated.
+  #
+  #  SyntaxError is raised if the given _string_ is invalid syntax. To overwrite this
+  #  behavior, <tt>error_tolerant: true</tt> can be provided. In this case, the parser
+  #  will produce a tree where expressions with syntax errors would be represented by
+  #  Node with <tt>type=:ERROR</tt>.
+  #
+  #     root = RubyVM::AbstractSyntaxTree.parse("x = 1; p(x; y=2")
+  #     # <internal:ast>:33:in `parse': syntax error, unexpected ';', expecting ')' (SyntaxError)
+  #     # x = 1; p(x; y=2
+  #     #           ^
+  #
+  #     root = RubyVM::AbstractSyntaxTree.parse("x = 1; p(x; y=2", error_tolerant: true)
+  #     # (SCOPE@1:0-1:15
+  #     #  tbl: [:x, :y]
+  #     #  args: nil
+  #     #  body: (BLOCK@1:0-1:15 (LASGN@1:0-1:5 :x (LIT@1:4-1:5 1)) (ERROR@1:7-1:11) (LASGN@1:12-1:15 :y (LIT@1:14-1:15 2))))
+  #     root.children.last.children
+  #     # [(LASGN@1:0-1:5 :x (LIT@1:4-1:5 1)),
+  #     #  (ERROR@1:7-1:11),
+  #     #  (LASGN@1:12-1:15 :y (LIT@1:14-1:15 2))]
+  #
+  #  Note that parsing continues even after the errored expression.
+  #
+  def self.parse string, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false
+    Primitive.ast_s_parse string, keep_script_lines, error_tolerant, keep_tokens
+  end
+
+  #  call-seq:
+  #     RubyVM::AbstractSyntaxTree.parse_file(pathname, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
+  #
+  #   Reads the file from _pathname_, then parses it like ::parse,
+  #   returning the root node of the abstract syntax tree.
+  #
+  #   SyntaxError is raised if _pathname_'s contents are not
+  #   valid Ruby syntax.
+  #
+  #     RubyVM::AbstractSyntaxTree.parse_file("my-app/app.rb")
+  #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-31:3>
+  #
+  #   See ::parse for explanation of keyword argument meaning and usage.
+  def self.parse_file pathname, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false
+    Primitive.ast_s_parse_file pathname, keep_script_lines, error_tolerant, keep_tokens
+  end
+
+  #  call-seq:
+  #     RubyVM::AbstractSyntaxTree.of(proc, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false)   -> RubyVM::AbstractSyntaxTree::Node
+  #     RubyVM::AbstractSyntaxTree.of(method, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
+  #
+  #   Returns AST nodes of the given _proc_ or _method_.
+  #
+  #     RubyVM::AbstractSyntaxTree.of(proc {1 + 2})
+  #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:35-1:42>
+  #
+  #     def hello
+  #       puts "hello, world"
+  #     end
+  #
+  #     RubyVM::AbstractSyntaxTree.of(method(:hello))
+  #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-3:3>
+  #
+  #   See ::parse for explanation of keyword argument meaning and usage.
+  def self.of body, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false
+    Primitive.ast_s_of body, keep_script_lines, error_tolerant, keep_tokens
+  end
+
+  #  call-seq:
+  #     RubyVM::AbstractSyntaxTree.node_id_for_backtrace_location(backtrace_location)   -> integer
+  #
+  #   Returns the node id for the given backtrace location.
+  #
+  #     begin
+  #       raise
+  #     rescue =>  e
+  #       loc = e.backtrace_locations.first
+  #       RubyVM::AbstractSyntaxTree.node_id_for_backtrace_location(loc)
+  #     end # => 0
+  def self.node_id_for_backtrace_location backtrace_location
+    Primitive.node_id_for_backtrace_location backtrace_location
+  end
+
+  # RubyVM::AbstractSyntaxTree::Node instances are created by parse methods in
+  # RubyVM::AbstractSyntaxTree.
+  #
+  # This class is MRI specific.
+  #
+  class Node
+
+    #  call-seq:
+    #     node.type -> symbol
+    #
+    #  Returns the type of this node as a symbol.
+    #
+    #    root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2")
+    #    root.type # => :SCOPE
+    #    lasgn = root.children[2]
+    #    lasgn.type # => :LASGN
+    #    call = lasgn.children[1]
+    #    call.type # => :OPCALL
+    def type
+      Primitive.ast_node_type
+    end
+
+    #  call-seq:
+    #     node.first_lineno -> integer
+    #
+    #  The line number in the source code where this AST's text began.
+    def first_lineno
+      Primitive.ast_node_first_lineno
+    end
+
+    #  call-seq:
+    #     node.first_column -> integer
+    #
+    #  The column number in the source code where this AST's text began.
+    def first_column
+      Primitive.ast_node_first_column
+    end
+
+    #  call-seq:
+    #     node.last_lineno -> integer
+    #
+    #  The line number in the source code where this AST's text ended.
+    def last_lineno
+      Primitive.ast_node_last_lineno
+    end
+
+    #  call-seq:
+    #     node.last_column -> integer
+    #
+    #  The column number in the source code where this AST's text ended.
+    def last_column
+      Primitive.ast_node_last_column
+    end
+
+    #  call-seq:
+    #     node.tokens -> array
+    #
+    #  Returns tokens corresponding to the location of the node.
+    #  Returns +nil+ if +keep_tokens+ is not enabled when #parse method is called.
+    #
+    #    root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2", keep_tokens: true)
+    #    root.tokens # => [[0, :tIDENTIFIER, "x", [1, 0, 1, 1]], [1, :tSP, " ", [1, 1, 1, 2]], ...]
+    #    root.tokens.map{_1[2]}.join # => "x = 1 + 2"
+    #
+    #  Token is an array of:
+    #
+    #  - id
+    #  - token type
+    #  - source code text
+    #  - location [ first_lineno, first_column, last_lineno, last_column ]
+    def tokens
+      return nil unless all_tokens
+
+      all_tokens.each_with_object([]) do |token, a|
+        loc = token.last
+        if ([first_lineno, first_column] <=> [loc[0], loc[1]]) <= 0 &&
+           ([last_lineno, last_column]   <=> [loc[2], loc[3]]) >= 0
+           a << token
+        end
+      end
+    end
+
+    #  call-seq:
+    #     node.all_tokens -> array
+    #
+    #  Returns all tokens for the input script regardless the receiver node.
+    #  Returns +nil+ if +keep_tokens+ is not enabled when #parse method is called.
+    #
+    #    root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2", keep_tokens: true)
+    #    root.all_tokens # => [[0, :tIDENTIFIER, "x", [1, 0, 1, 1]], [1, :tSP, " ", [1, 1, 1, 2]], ...]
+    #    root.children[-1].all_tokens # => [[0, :tIDENTIFIER, "x", [1, 0, 1, 1]], [1, :tSP, " ", [1, 1, 1, 2]], ...]
+    def all_tokens
+      Primitive.ast_node_all_tokens
+    end
+
+    #  call-seq:
+    #     node.children -> array
+    #
+    #  Returns AST nodes under this one.  Each kind of node
+    #  has different children, depending on what kind of node it is.
+    #
+    #  The returned array may contain other nodes or <code>nil</code>.
+    def children
+      Primitive.ast_node_children
+    end
+
+    #  call-seq:
+    #     node.inspect -> string
+    #
+    #  Returns debugging information about this node as a string.
+    def inspect
+      Primitive.ast_node_inspect
+    end
+
+    #  call-seq:
+    #     node.node_id -> integer
+    #
+    #  Returns an internal node_id number.
+    #  Note that this is an API for ruby internal use, debugging,
+    #  and research. Do not use this for any other purpose.
+    #  The compatibility is not guaranteed.
+    def node_id
+      Primitive.ast_node_node_id
+    end
+
+    #  call-seq:
+    #     node.script_lines -> array
+    #
+    #  Returns the original source code as an array of lines.
+    #
+    #  Note that this is an API for ruby internal use, debugging,
+    #  and research. Do not use this for any other purpose.
+    #  The compatibility is not guaranteed.
+    def script_lines
+      Primitive.ast_node_script_lines
+    end
+
+    #  call-seq:
+    #     node.source -> string
+    #
+    #  Returns the code fragment that corresponds to this AST.
+    #
+    #  Note that this is an API for ruby internal use, debugging,
+    #  and research. Do not use this for any other purpose.
+    #  The compatibility is not guaranteed.
+    #
+    #  Also note that this API may return an incomplete code fragment
+    #  that does not parse; for example, a here document following
+    #  an expression may be dropped.
+    def source
+      lines = script_lines
+      if lines
+        lines = lines[first_lineno - 1 .. last_lineno - 1]
+        lines[-1] = lines[-1].byteslice(0...last_column)
+        lines[0] = lines[0].byteslice(first_column..-1)
+        lines.join
+      else
+        nil
+      end
+    end
+
+    #  call-seq:
+    #     node.locations -> array
+    #
+    #  Returns location objects associated with the AST node.
+    #  The returned array contains RubyVM::AbstractSyntaxTree::Location.
+    def locations
+      Primitive.ast_node_locations
+    end
+  end
+
+  # RubyVM::AbstractSyntaxTree::Location instances are created by
+  # RubyVM::AbstractSyntaxTree::Node#locations.
+  #
+  # This class is MRI specific.
+  #
+  class Location
+
+    #  call-seq:
+    #     location.first_lineno -> integer
+    #
+    #  The line number in the source code where this AST's text began.
+    def first_lineno
+      Primitive.ast_location_first_lineno
+    end
+
+    #  call-seq:
+    #     location.first_column -> integer
+    #
+    #  The column number in the source code where this AST's text began.
+    def first_column
+      Primitive.ast_location_first_column
+    end
+
+    #  call-seq:
+    #     location.last_lineno -> integer
+    #
+    #  The line number in the source code where this AST's text ended.
+    def last_lineno
+      Primitive.ast_location_last_lineno
+    end
+
+    #  call-seq:
+    #     location.last_column -> integer
+    #
+    #  The column number in the source code where this AST's text ended.
+    def last_column
+      Primitive.ast_location_last_column
+    end
+
+    #  call-seq:
+    #     location.inspect -> string
+    #
+    #  Returns debugging information about this location as a string.
+    def inspect
+      Primitive.ast_location_inspect
+    end
+  end
+end
diff --git a/autogen.sh b/autogen.sh
new file mode 100755
index 0000000000..6cbc5dddab
--- /dev/null
+++ b/autogen.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+# Clear PWD to force commands to recompute working directory
+PWD=
+
+# Figure out the source directory for this script
+# configure.ac should be in the same place
+case "$0" in
+    */* )  srcdir=`dirname "$0"` ;; # Called with path
+    *   )  srcdir="";; # Otherwise
+esac
+
+# If install-only is explicitly requested, disable symlink flags
+case " $* " in
+    *" -i "* | *" --install"* ) symlink_flags="" ;;
+    *                         ) symlink_flags="--install --symlink" ;;
+esac
+
+exec ${AUTORECONF:-autoreconf} \
+     $symlink_flags \
+     "$@" \
+     $srcdir
diff --git a/basictest/test.rb b/basictest/test.rb
index 10ea28d320..711e4f4ab3 100755
--- a/basictest/test.rb
+++ b/basictest/test.rb
@@ -879,7 +879,7 @@ $x.sort!{|a,b| b-a}		# reverse sort
 test_ok($x == [7,5,3,2,1])
 
 # split test
-$x = "The Book of Mormon"
+$x = +"The Book of Mormon"
 test_ok($x.split(//).reverse!.join == $x.reverse)
 test_ok($x.reverse == $x.reverse!)
 test_ok("1 byte string".split(//).reverse.join(":") == "g:n:i:r:t:s: :e:t:y:b: :1")
@@ -1425,9 +1425,6 @@ marity_test(:test_ok)
 marity_test(:marity_test)
 marity_test(:p)
 
-lambda(&method(:test_ok)).call(true)
-lambda(&block_get{|a,n| test_ok(a,n)}).call(true, 2)
-
 class ITER_TEST1
    def a
      block_given?
@@ -1646,7 +1643,7 @@ test_ok(/^(?:ab+)+/ =~ "ababb" && $& == "ababb")
 test_ok(/(\s+\d+){2}/ =~ " 1 2" && $& == " 1 2")
 test_ok(/(?:\s+\d+){2}/ =~ " 1 2" && $& == " 1 2")
 
-$x = <<END;
+$x = +<<END;
 ABCD
 ABCD
 END
@@ -1685,12 +1682,12 @@ test_ok(?a == ?a)
 test_ok(?\C-a == "\1")
 test_ok(?\M-a == "\341")
 test_ok(?\M-\C-a == "\201")
-test_ok("a".upcase![0] == ?A)
-test_ok("A".downcase![0] == ?a)
-test_ok("abc".tr!("a-z", "A-Z") == "ABC")
-test_ok("aabbcccc".tr_s!("a-z", "A-Z") == "ABC")
-test_ok("abcc".squeeze!("a-z") == "abc")
-test_ok("abcd".delete!("bc") == "ad")
+test_ok("a".dup.upcase![0] == ?A)
+test_ok("A".dup.downcase![0] == ?a)
+test_ok("abc".dup.tr!("a-z", "A-Z") == "ABC")
+test_ok("aabbcccc".dup.tr_s!("a-z", "A-Z") == "ABC")
+test_ok("abcc".dup.squeeze!("a-z") == "abc")
+test_ok("abcd".dup.delete!("bc") == "ad")
 
 $x = "abcdef"
 $y = [ ?a, ?b, ?c, ?d, ?e, ?f ]
@@ -1703,7 +1700,7 @@ $x.each_byte {|i|
 }
 test_ok(!$bad)
 
-s = "a string"
+s = +"a string"
 s[0..s.size]="another string"
 test_ok(s == "another string")
 
@@ -1732,7 +1729,7 @@ a = nil
 test_ok(defined?(a))
 test_ok(a == nil)
 
-# multiple asignment
+# multiple assignment
 a, b = 1, 2
 test_ok(a == 1 && b == 2)
 
@@ -1963,6 +1960,8 @@ test_ok(p1.call == 5)
 test_ok(i7 == nil)
 end
 
+# WASI doesn't support spawning a new process for now.
+unless /wasi/ =~ RUBY_PLATFORM
 test_check "system"
 test_ok(`echo foobar` == "foobar\n")
 test_ok(`./miniruby -e 'print "foobar"'` == 'foobar')
@@ -2013,6 +2012,7 @@ test_ok(done)
 
 File.unlink script_tmp or `/bin/rm -f "#{script_tmp}"`
 File.unlink "#{script_tmp}.bak" or `/bin/rm -f "#{script_tmp}.bak"`
+end # not /wasi/ =~ RUBY_PLATFORM
 
 test_check "const"
 TEST1 = 1
@@ -2140,7 +2140,7 @@ $_ = foobar
 test_ok($_ == foobar)
 
 class Gods
-  @@rule = "Uranus"		# private to Gods
+  @@rule = "Uranus"
   def ruler0
     @@rule
   end
@@ -2163,7 +2163,7 @@ module Olympians
 end
 
 class Titans < Gods
-  @@rule = "Cronus"		# do not affect @@rule in Gods
+  @@rule = "Cronus"		# modifies @@rule in Gods
   include Olympians
   def ruler4
     @@rule
@@ -2178,7 +2178,14 @@ test_ok(Titans.ruler2 == "Cronus")
 atlas = Titans.new
 test_ok(atlas.ruler0 == "Cronus")
 test_ok(atlas.ruler3 == "Zeus")
-test_ok(atlas.ruler4 == "Cronus")
+begin
+  atlas.ruler4
+rescue RuntimeError => e
+  test_ok(e.message.include?("class variable @@rule of Olympians is overtaken by Gods"))
+else
+  test_ok(false)
+end
+test_ok(atlas.ruler3 == "Zeus")
 
 test_check "trace"
 $x = 1234
diff --git a/benchmark/README.md b/benchmark/README.md
index 24a2669143..9f9192685e 100644
--- a/benchmark/README.md
+++ b/benchmark/README.md
@@ -27,17 +27,20 @@ benchmark-driver benchmark/*.yml
 See also:
 
 ```console
+benchmark-driver --help
 Usage: benchmark-driver [options] RUBY|YAML...
-    -r, --runner TYPE                Specify runner type: ips, time, memory, once (default: ips)
-    -o, --output TYPE                Specify output type: compare, simple, markdown, record (default: compare)
+    -r, --runner TYPE                Specify runner type: ips, time, memory, once, block (default: ips)
+    -o, --output TYPE                Specify output type: compare, simple, markdown, record, all (default: compare)
     -e, --executables EXECS          Ruby executables (e1::path1 arg1; e2::path2 arg2;...)
         --rbenv VERSIONS             Ruby executables in rbenv (x.x.x arg1;y.y.y arg2;...)
         --repeat-count NUM           Try benchmark NUM times and use the fastest result or the worst memory usage
         --repeat-result TYPE         Yield "best", "average" or "worst" result with --repeat-count (default: best)
+        --alternate                  Alternate executables instead of running the same executable in a row with --repeat-count
         --bundler                    Install and use gems specified in Gemfile
         --filter REGEXP              Filter out benchmarks with given regexp
         --run-duration SECONDS       Warmup estimates loop_count to run for this duration (default: 3)
-    -v, --verbose                    Verbose mode. Multiple -v options increase visilibity (max: 2)
+        --timeout SECONDS            Timeout ruby command execution with timeout(1)
+    -v, --verbose                    Verbose mode. Multiple -v options increase visibility (max: 2)
 ```
 
 ## make benchmark
@@ -53,20 +56,20 @@ make benchmark
 # Or compare with specific ruby binary
 make benchmark COMPARE_RUBY="/path/to/ruby --jit"
 
-# Run vm1 benchmarks
-make benchmark ITEM=vm1
+# Run vm benchmarks
+make benchmark ITEM=vm
 
 # Run some limited benchmarks in ITEM-matched files
-make benchmark ITEM=vm1 OPTS=--filter=block
+make benchmark ITEM=vm OPTS=--filter=block
 
 # You can specify the benchmark by an exact filename instead of using the default argument:
 # ARGS = $$(find $(srcdir)/benchmark -maxdepth 1 -name '*$(ITEM)*.yml' -o -name '*$(ITEM)*.rb')
-make benchmark ARGS=../benchmark/erb_render.yml
+make benchmark ARGS=benchmark/erb_render.yml
 
 # You can specify any option via $OPTS
 make benchmark OPTS="--help"
 
 # With `make benchmark`, some special runner plugins are available:
 #   -r peak, -r size, -r total, -r utime, -r stime, -r cutime, -r cstime
-make benchmark ITEM=vm2_bigarray OPTS="-r peak"
+make benchmark ITEM=vm_bigarray OPTS="-r peak"
 ```
diff --git a/benchmark/app_aobench.rb b/benchmark/app_aobench.rb
index 16296af12b..c1546e08ab 100644
--- a/benchmark/app_aobench.rb
+++ b/benchmark/app_aobench.rb
@@ -151,7 +151,7 @@ def clamp(f)
   i.to_i
 end
 
-def otherBasis(basis, n)
+def orthoBasis(basis, n)
   basis[2] = Vec.new(n.x, n.y, n.z)
   basis[1] = Vec.new(0.0, 0.0, 0.0)
 
@@ -183,7 +183,7 @@ class Scene
 
   def ambient_occlusion(isect)
     basis = Array.new
-    otherBasis(basis, isect.n)
+    orthoBasis(basis, isect.n)
 
     ntheta    = NAO_SAMPLES
     nphi      = NAO_SAMPLES
diff --git a/benchmark/app_fib.rb b/benchmark/app_fib.rb
index 34a7b2e725..e61bc8aa32 100644
--- a/benchmark/app_fib.rb
+++ b/benchmark/app_fib.rb
@@ -1,4 +1,4 @@
-def fib n
+def fib(n)
   if n < 3
     1
   else
diff --git a/benchmark/array_intersection.yml b/benchmark/array_intersection.yml
new file mode 100644
index 0000000000..26705323fd
--- /dev/null
+++ b/benchmark/array_intersection.yml
@@ -0,0 +1,14 @@
+prelude: |
+  small1 = [1, 2, 3]
+  small2 = [1, 2, 3, 4, 5]
+  small3 = [2, 3, 4, 5]
+  small4 = [2]
+  big1 = [1, 2, 3, 4] * 64
+  big2 = [1, 2, 3] * 64
+  big3 = [1, 2] * 64
+
+benchmark:
+  small-&: small1 & small2 & small3 & small4
+  small-intersection: small1.intersection(small2, small3, small4)
+  big-&: big1 & big2 & big3
+  big-intersection: big1.intersection(big2, big3)
diff --git a/benchmark/array_large_literal.yml b/benchmark/array_large_literal.yml
new file mode 100644
index 0000000000..423d68391f
--- /dev/null
+++ b/benchmark/array_large_literal.yml
@@ -0,0 +1,19 @@
+prelude: |
+  def def_array(size)
+    Object.class_eval(<<-END)
+      def array_#{size}
+        x = 1
+        [#{(['x'] * size).join(',')}]
+      end
+    END
+  end
+  def_array(100)
+  def_array(1000)
+  def_array(10000)
+  def_array(100000)
+benchmark:
+  array_100: array_100
+  array_1000: array_1000
+  array_10000: array_10000
+  array_100000: array_100000
+
diff --git a/benchmark/array_max_float.yml b/benchmark/array_max_float.yml
new file mode 100644
index 0000000000..ace1ae2e14
--- /dev/null
+++ b/benchmark/array_max_float.yml
@@ -0,0 +1,30 @@
+prelude: |
+  ary2 = 2.times.map(&:to_f).shuffle
+  ary10 = 10.times.map(&:to_f).shuffle
+  ary100 = 100.times.map(&:to_f).shuffle
+  ary500 = 500.times.map(&:to_f).shuffle
+  ary1000 = 1000.times.map(&:to_f).shuffle
+  ary2000 = 2500.times.map(&:to_f).shuffle
+  ary3000 = 2500.times.map(&:to_f).shuffle
+  ary5000 = 5000.times.map(&:to_f).shuffle
+  ary10000 = 10000.times.map(&:to_f).shuffle
+  ary20000 = 20000.times.map(&:to_f).shuffle
+  ary50000 = 50000.times.map(&:to_f).shuffle
+  ary100000 = 100000.times.map(&:to_f).shuffle
+
+benchmark:
+  ary2.max: ary2.max
+  ary10.max: ary10.max
+  ary100.max: ary100.max
+  ary500.max: ary500.max
+  ary1000.max: ary1000.max
+  ary2000.max: ary2000.max
+  ary3000.max: ary3000.max
+  ary5000.max: ary5000.max
+  ary10000.max: ary10000.max
+  ary20000.max: ary20000.max
+  ary50000.max: ary50000.max
+  ary100000.max: ary100000.max
+
+loop_count: 10000
+
diff --git a/benchmark/array_max_int.yml b/benchmark/array_max_int.yml
new file mode 100644
index 0000000000..acd83684d0
--- /dev/null
+++ b/benchmark/array_max_int.yml
@@ -0,0 +1,31 @@
+prelude: |
+  ary2 = 2.times.to_a.shuffle
+  ary10 = 10.times.to_a.shuffle
+  ary100 = 100.times.to_a.shuffle
+  ary500 = 500.times.to_a.shuffle
+  ary1000 = 1000.times.to_a.shuffle
+  ary2000 = 2500.times.to_a.shuffle
+  ary3000 = 2500.times.to_a.shuffle
+  ary5000 = 5000.times.to_a.shuffle
+  ary10000 = 10000.times.to_a.shuffle
+  ary20000 = 20000.times.to_a.shuffle
+  ary50000 = 50000.times.to_a.shuffle
+  ary100000 = 100000.times.to_a.shuffle
+  ary1000000 = 1000000.times.to_a.shuffle
+
+benchmark:
+  ary2.max: ary2.max
+  ary10.max: ary10.max
+  ary100.max: ary100.max
+  ary500.max: ary500.max
+  ary1000.max: ary1000.max
+  ary2000.max: ary2000.max
+  ary3000.max: ary3000.max
+  ary5000.max: ary5000.max
+  ary10000.max: ary10000.max
+  ary20000.max: ary20000.max
+  ary50000.max: ary50000.max
+  ary100000.max: ary100000.max
+  ary1000000.max: ary1000000.max
+
+loop_count: 10000
diff --git a/benchmark/array_max_str.yml b/benchmark/array_max_str.yml
new file mode 100644
index 0000000000..2aeed010f2
--- /dev/null
+++ b/benchmark/array_max_str.yml
@@ -0,0 +1,30 @@
+prelude: |
+  ary2 = 2.times.map(&:to_s).shuffle
+  ary10 = 10.times.map(&:to_s).shuffle
+  ary100 = 100.times.map(&:to_s).shuffle
+  ary500 = 500.times.map(&:to_s).shuffle
+  ary1000 = 1000.times.map(&:to_s).shuffle
+  ary2000 = 2500.times.map(&:to_s).shuffle
+  ary3000 = 2500.times.map(&:to_s).shuffle
+  ary5000 = 5000.times.map(&:to_s).shuffle
+  ary10000 = 10000.times.map(&:to_s).shuffle
+  ary20000 = 20000.times.map(&:to_s).shuffle
+  ary50000 = 50000.times.map(&:to_s).shuffle
+  ary100000 = 100000.times.map(&:to_s).shuffle
+
+benchmark:
+  ary2.max: ary2.max
+  ary10.max: ary10.max
+  ary100.max: ary100.max
+  ary500.max: ary500.max
+  ary1000.max: ary1000.max
+  ary2000.max: ary2000.max
+  ary3000.max: ary3000.max
+  ary5000.max: ary5000.max
+  ary10000.max: ary10000.max
+  ary20000.max: ary20000.max
+  ary50000.max: ary50000.max
+  ary100000.max: ary100000.max
+
+loop_count: 10000
+
diff --git a/benchmark/array_min.yml b/benchmark/array_min.yml
new file mode 100644
index 0000000000..53e5072b14
--- /dev/null
+++ b/benchmark/array_min.yml
@@ -0,0 +1,31 @@
+prelude: |
+  ary2 = 2.times.to_a.shuffle
+  ary10 = 10.times.to_a.shuffle
+  ary100 = 100.times.to_a.shuffle
+  ary500 = 500.times.to_a.shuffle
+  ary1000 = 1000.times.to_a.shuffle
+  ary2000 = 2500.times.to_a.shuffle
+  ary3000 = 2500.times.to_a.shuffle
+  ary5000 = 5000.times.to_a.shuffle
+  ary10000 = 10000.times.to_a.shuffle
+  ary20000 = 20000.times.to_a.shuffle
+  ary50000 = 50000.times.to_a.shuffle
+  ary100000 = 100000.times.to_a.shuffle
+  ary1000000 = 1000000.times.to_a.shuffle
+
+benchmark:
+  ary2.min: ary2.min
+  ary10.min: ary10.min
+  ary100.min: ary100.min
+  ary500.min: ary500.min
+  ary1000.min: ary1000.min
+  ary2000.min: ary2000.min
+  ary3000.min: ary3000.min
+  ary5000.min: ary5000.min
+  ary10000.min: ary10000.min
+  ary20000.min: ary20000.min
+  ary50000.min: ary50000.min
+  ary100000.min: ary100000.min
+  ary1000000.min: ary1000000.min
+
+loop_count: 10000
diff --git a/benchmark/array_sample.yml b/benchmark/array_sample.yml
new file mode 100644
index 0000000000..1cd2b34794
--- /dev/null
+++ b/benchmark/array_sample.yml
@@ -0,0 +1,4 @@
+prelude: ary = (1..10_000).to_a
+benchmark:
+  - ary.sample
+  - ary.sample(2)
diff --git a/benchmark/array_sort_int.yml b/benchmark/array_sort_int.yml
new file mode 100644
index 0000000000..7b9027ebf7
--- /dev/null
+++ b/benchmark/array_sort_int.yml
@@ -0,0 +1,15 @@
+prelude: |
+  ary2 = 2.times.to_a.shuffle
+  ary10 = 10.times.to_a.shuffle
+  ary100 = 100.times.to_a.shuffle
+  ary1000 = 1000.times.to_a.shuffle
+  ary10000 = 10000.times.to_a.shuffle
+
+benchmark:
+  ary2.sort: ary2.sort
+  ary10.sort: ary10.sort
+  ary100.sort: ary100.sort
+  ary1000.sort: ary1000.sort
+  ary10000.sort: ary10000.sort
+
+loop_count: 10000
diff --git a/benchmark/attr_accessor.yml b/benchmark/attr_accessor.yml
new file mode 100644
index 0000000000..82134cdf9b
--- /dev/null
+++ b/benchmark/attr_accessor.yml
@@ -0,0 +1,29 @@
+prelude: |
+  class C
+    attr_accessor :x
+    def initialize
+      @x = nil
+    end
+    class_eval <<-END
+      def ar
+        #{'x;'*256}
+      end
+      def aw
+        #{'self.x = nil;'*256}
+      end
+      def arm
+        m = method(:x)
+        #{'m.call;'*256}
+      end
+      def awm
+        m = method(:x=)
+        #{'m.call(nil);'*256}
+      end
+    END
+  end
+  obj = C.new
+benchmark:
+  attr_reader: "obj.ar"
+  attr_writer: "obj.aw"
+  attr_reader_method: "obj.arm"
+  attr_writer_method: "obj.awm"
diff --git a/benchmark/buffer_each.yml b/benchmark/buffer_each.yml
new file mode 100644
index 0000000000..417941104e
--- /dev/null
+++ b/benchmark/buffer_each.yml
@@ -0,0 +1,27 @@
+prelude: |
+  # frozen_string_literal: true
+  Warning[:experimental] = false
+  string = "The quick brown fox jumped over the lazy dog."
+  array = string.bytes
+  buffer = IO::Buffer.for(string)
+benchmark:
+  string.each_byte: |
+    upcased = String.new
+    string.each_byte do |byte|
+      upcased << (byte ^ 32)
+    end
+  array.each: |
+    upcased = String.new
+    array.each do |byte|
+      upcased << (byte ^ 32)
+    end
+  buffer.each: |
+    upcased = String.new
+    buffer.each(:U8) do |offset, byte|
+      upcased << (byte ^ 32)
+    end
+  buffer.each_byte: |
+    upcased = String.new
+    buffer.each_byte do |byte|
+      upcased << (byte ^ 32)
+    end
diff --git a/benchmark/buffer_get.yml b/benchmark/buffer_get.yml
new file mode 100644
index 0000000000..9e1f99d64e
--- /dev/null
+++ b/benchmark/buffer_get.yml
@@ -0,0 +1,25 @@
+prelude: |
+  # frozen_string_literal: true
+  Warning[:experimental] = false
+  string = "The quick brown fox jumped over the lazy dog."
+  buffer = IO::Buffer.for(string)
+  format = [:U32, :U32, :U32, :U32]
+benchmark:
+  string.unpack1: |
+    [
+      string.unpack1("N"),
+      string.unpack1("N", offset: 4),
+      string.unpack1("N", offset: 8),
+      string.unpack1("N", offset: 12),
+    ]
+  buffer.get_value: |
+    [
+      buffer.get_value(:U32, 0),
+      buffer.get_value(:U32, 4),
+      buffer.get_value(:U32, 8),
+      buffer.get_value(:U32, 12),
+    ]
+  buffer.get_values: |
+    buffer.get_values(format, 0)
+  string.unpack: |
+    string.unpack("NNNN")
diff --git a/benchmark/cgi_escape_html.yml b/benchmark/cgi_escape_html.yml
index af6abd08ac..655be9d7d8 100644
--- a/benchmark/cgi_escape_html.yml
+++ b/benchmark/cgi_escape_html.yml
@@ -1,32 +1,23 @@
-prelude: require 'cgi/escape'
+prelude: |
+  # frozen_string_literal: true
+  require 'cgi/escape'
 benchmark:
-  - name: escape_html_blank
-    prelude: str = ""
-    script: CGI.escapeHTML(str)
+  - script: CGI.escapeHTML("")
     loop_count: 20000000
-  - name: escape_html_short_none
-    prelude: str = "abcde"
-    script: CGI.escapeHTML(str)
+  - script: CGI.escapeHTML("abcde")
     loop_count: 20000000
-  - name: escape_html_short_one
-    prelude: str = "abcd<"
-    script: CGI.escapeHTML(str)
+  - script: CGI.escapeHTML("abcd<")
     loop_count: 20000000
-  - name: escape_html_short_all
-    prelude: str = "'&\"<>"
-    script: CGI.escapeHTML(str)
+  - script: CGI.escapeHTML("'&\"<>")
     loop_count: 5000000
-  - name: escape_html_long_none
-    prelude: str = "abcde" * 300
-    script: CGI.escapeHTML(str)
+  - prelude: long_no_escape = "abcde" * 300
+    script: CGI.escapeHTML(long_no_escape)
     loop_count: 1000000
-  - name: escape_html_long_all
-    prelude: str = "'&\"<>" * 10
-    script: CGI.escapeHTML(str)
+  - prelude: long_all_escape = "'&\"<>" * 10
+    script: CGI.escapeHTML(long_all_escape)
     loop_count: 1000000
-  - name: escape_html_real
-    prelude: | # http://example.com/
-      str = <<~HTML
+  - prelude: | # http://example.com/
+      example_html = <<~HTML
         <body>
         <div>
             <h1>Example Domain</h1>
@@ -36,5 +27,5 @@ benchmark:
         </div>
         </body>
       HTML
-    script: CGI.escapeHTML(str)
+    script: CGI.escapeHTML(example_html)
     loop_count: 1000000
diff --git a/benchmark/class_superclass.yml b/benchmark/class_superclass.yml
new file mode 100644
index 0000000000..847ff811f1
--- /dev/null
+++ b/benchmark/class_superclass.yml
@@ -0,0 +1,23 @@
+prelude: |
+  class SimpleClass; end
+  class OneModuleClass
+    1.times { include Module.new }
+  end
+  class MediumClass
+    10.times { include Module.new }
+  end
+  class LargeClass
+    100.times { include Module.new }
+  end
+benchmark:
+  object_class_superclass: |
+    Object.superclass
+  simple_class_superclass: |
+    SimpleClass.superclass
+  one_module_class: |
+    OneModuleClass.superclass
+  medium_class_superclass: |
+    MediumClass.superclass
+  large_class_superclass: |
+    LargeClass.superclass
+loop_count: 20000000
diff --git a/benchmark/constant_invalidation.rb b/benchmark/constant_invalidation.rb
new file mode 100644
index 0000000000..a95ec6f37e
--- /dev/null
+++ b/benchmark/constant_invalidation.rb
@@ -0,0 +1,22 @@
+$VERBOSE = nil
+
+CONSTANT1 = 1
+CONSTANT2 = 1
+CONSTANT3 = 1
+CONSTANT4 = 1
+CONSTANT5 = 1
+
+def constants
+  [CONSTANT1, CONSTANT2, CONSTANT3, CONSTANT4, CONSTANT5]
+end
+
+500_000.times do
+  constants
+
+  # With previous behavior, this would cause all of the constant caches
+  # associated with the constant lookups listed above to invalidate, meaning
+  # they would all have to be fetched again. With current behavior, it only
+  # invalidates when a name matches, so the following constant set shouldn't
+  # impact the constant lookups listed above.
+  INVALIDATE = true
+end
diff --git a/benchmark/dir_pwd.yml b/benchmark/dir_pwd.yml
new file mode 100644
index 0000000000..c435d3ac5e
--- /dev/null
+++ b/benchmark/dir_pwd.yml
@@ -0,0 +1,2 @@
+benchmark:
+  pwd: Dir.pwd
diff --git a/benchmark/enum_lazy_flat_map.yml b/benchmark/enum_lazy_flat_map.yml
new file mode 100644
index 0000000000..0ee390a441
--- /dev/null
+++ b/benchmark/enum_lazy_flat_map.yml
@@ -0,0 +1,16 @@
+prelude: |
+  num = (1..).lazy.take(100)
+  ary2 = [[1,2]].cycle.lazy.take(10)
+  ary10 = [[*1..10]].cycle.lazy.take(10)
+  ary20 = [[*1..20]].cycle.lazy.take(10)
+  ary50 = [[*1..50]].cycle.lazy.take(10)
+  ary100 = [[*1..100]].cycle.lazy.take(10)
+
+benchmark:
+  num3: num.flat_map {|x| x}.take(3).to_a
+  num10: num.flat_map {|x| x}.take(3).to_a
+  ary2:  ary2.flat_map {|x| x}.take(3).to_a
+  ary10: ary10.flat_map {|x| x}.take(3).to_a
+  ary20: ary20.flat_map {|x| x}.take(3).to_a
+  ary50: ary50.flat_map {|x| x}.take(3).to_a
+  ary100: ary100.flat_map {|x| x}.take(3).to_a
diff --git a/benchmark/enum_lazy_zip.yml b/benchmark/enum_lazy_zip.yml
new file mode 100644
index 0000000000..4566ff0261
--- /dev/null
+++ b/benchmark/enum_lazy_zip.yml
@@ -0,0 +1,22 @@
+prelude: |
+  a = (1..3).lazy
+  b = a.map {|x| x}
+
+benchmark:
+  first_ary: a.zip(["a", "b", "c"]).first
+  first_nonary: a.zip("a".."c").first
+  first_noarg: a.zip.first
+
+  take3_ary: a.zip(["a", "b", "c"]).take(3).force
+  take3_nonary: a.zip("a".."c").take(3).force
+  take3_noarg: a.zip.take(3).force
+
+  chain-first_ary: b.zip(["a", "b", "c"]).first
+  chain-first_nonary: b.zip("a".."c").first
+  chain-first_noarg: b.zip.first
+
+  chain-take3_ary: b.zip(["a", "b", "c"]).take(3).force
+  chain-take3_nonary: b.zip("a".."c").take(3).force
+  chain-take3_noarg: b.zip.take(3).force
+
+  block: a.zip("a".."c") {|x, y| [x, y]}
diff --git a/benchmark/enum_minmax.yml b/benchmark/enum_minmax.yml
new file mode 100644
index 0000000000..9d01731abb
--- /dev/null
+++ b/benchmark/enum_minmax.yml
@@ -0,0 +1,25 @@
+prelude: |
+  set2 = 2.times.to_a.shuffle.to_set
+  set10 = 10.times.to_a.shuffle.to_set
+  set100 = 100.times.to_a.shuffle.to_set
+  set1000 = 1000.times.to_a.shuffle.to_set
+  set10000 = 10000.times.to_a.shuffle.to_set
+
+benchmark:
+  set2.min: set2.min
+  set10.min: set10.min
+  set100.min: set100.min
+  set1000.min: set1000.min
+  set10000.min: set10000.min
+  set2.max: set2.max
+  set10.max: set10.max
+  set100.max: set100.max
+  set1000.max: set1000.max
+  set10000.max: set10000.max
+  set2.minmax: set2.minmax
+  set10.minmax: set10.minmax
+  set100.minmax: set100.minmax
+  set1000.minmax: set1000.minmax
+  set10000.minmax: set10000.minmax
+
+loop_count: 10000
diff --git a/benchmark/enum_sort.yml b/benchmark/enum_sort.yml
new file mode 100644
index 0000000000..6f26e748c6
--- /dev/null
+++ b/benchmark/enum_sort.yml
@@ -0,0 +1,15 @@
+prelude: |
+  set2 = 2.times.to_a.shuffle.to_set
+  set10 = 10.times.to_a.shuffle.to_set
+  set100 = 100.times.to_a.shuffle.to_set
+  set1000 = 1000.times.to_a.shuffle.to_set
+  set10000 = 10000.times.to_a.shuffle.to_set
+
+benchmark:
+  set2.sort_by: set2.sort_by { 0 }
+  set10.sort_by: set10.sort_by { 0 }
+  set100.sort_by: set100.sort_by { 0 }
+  set1000.sort_by: set1000.sort_by { 0 }
+  set10000.sort_by: set10000.sort_by { 0 }
+
+loop_count: 10000
diff --git a/benchmark/enum_sort_by.yml b/benchmark/enum_sort_by.yml
new file mode 100644
index 0000000000..d386353888
--- /dev/null
+++ b/benchmark/enum_sort_by.yml
@@ -0,0 +1,53 @@
+prelude: |
+  array_length = 2
+  fixnum_array2 = array_length.times.to_a.map {rand(10000)}
+  float_array2 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array2 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array2 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array2 =array_length.times.to_a.map {0}
+
+  array_length = 10
+  fixnum_array10 = array_length.times.to_a.map {rand(10000)}
+  float_array10 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array10 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array10 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array10 =array_length.times.to_a.map {0}
+
+  array_length = 1000
+  fixnum_array1000 = array_length.times.to_a.map {rand(10000)}
+  float_array1000 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array1000 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array1000 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array1000 =array_length.times.to_a.map {0}
+
+  array_length = 100000
+  fixnum_array100000 = array_length.times.to_a.map {rand(10000)}
+  float_array100000 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array100000 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array100000 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array100000 =array_length.times.to_a.map {0}
+
+benchmark:
+  fixnum_array2.sort_by: fixnum_array2.sort_by {|a| a}
+  float_array2.sort_by:  float_array2.sort_by {|a| a}
+  string_length2.sort_by: string_array2.sort_by {|a| a.length}
+  mix_array2.sort_by:  mix_array2.sort_by {|a| a}
+  all_zero2.sort_by: all_zero_array2.sort_by{|a| a}
+
+  fixnum_array10.sort_by: fixnum_array10.sort_by {|a| a}
+  float_array10.sort_by:  float_array10.sort_by {|a| a}
+  string_length10.sort_by: string_array10.sort_by {|a| a.length}
+  mix_array10.sort_by:  mix_array10.sort_by {|a| a}
+  all_zero10.sort_by: all_zero_array10.sort_by{|a| a}
+
+  fixnum_array1000.sort_by: fixnum_array1000.sort_by {|a| a}
+  float_array1000.sort_by:  float_array1000.sort_by {|a| a}
+  string_length1000.sort_by: string_array1000.sort_by {|a| a.length}
+  mix_array1000.sort_by:  mix_array1000.sort_by {|a| a}
+  all_zero1000.sort_by: all_zero_array1000.sort_by{|a| a}
+
+  fixnum_array100000.sort_by: fixnum_array100000.sort_by {|a| a}
+  float_array100000.sort_by:  float_array100000.sort_by {|a| a}
+  string_length100000.sort_by: string_array100000.sort_by {|a| a.length}
+  mix_array100000.sort_by:  mix_array100000.sort_by {|a| a}
+  all_zero100000.sort_by: all_zero_array100000.sort_by{|a| a}
diff --git a/benchmark/enum_tally.yml b/benchmark/enum_tally.yml
new file mode 100644
index 0000000000..edd2e040a0
--- /dev/null
+++ b/benchmark/enum_tally.yml
@@ -0,0 +1,4 @@
+prelude: |
+  list = ("aaa".."zzz").to_a*10
+benchmark:
+  tally: list.tally
diff --git a/benchmark/erb_escape_html.yml b/benchmark/erb_escape_html.yml
new file mode 100644
index 0000000000..ca28d756e7
--- /dev/null
+++ b/benchmark/erb_escape_html.yml
@@ -0,0 +1,31 @@
+prelude: |
+  # frozen_string_literal: true
+  require 'erb'
+benchmark:
+  - script: ERB::Util.html_escape("")
+    loop_count: 20000000
+  - script: ERB::Util.html_escape("abcde")
+    loop_count: 20000000
+  - script: ERB::Util.html_escape("abcd<")
+    loop_count: 20000000
+  - script: ERB::Util.html_escape("'&\"<>")
+    loop_count: 5000000
+  - prelude: long_no_escape = "abcde" * 300
+    script: ERB::Util.html_escape(long_no_escape)
+    loop_count: 1000000
+  - prelude: long_all_escape = "'&\"<>" * 10
+    script: ERB::Util.html_escape(long_all_escape)
+    loop_count: 1000000
+  - prelude: | # http://example.com/
+      example_html = <<~HTML
+        <body>
+        <div>
+            <h1>Example Domain</h1>
+            <p>This domain is established to be used for illustrative examples in documents. You may use this
+            domain in examples without prior coordination or asking for permission.</p>
+            <p><a href="http://www.iana.org/domains/example">More information...</a></p>
+        </div>
+        </body>
+      HTML
+    script: ERB::Util.html_escape(example_html)
+    loop_count: 1000000
diff --git a/benchmark/fiber_chain.yml b/benchmark/fiber_chain.yml
index a36c759f8e..a36c759f8e 100755..100644
--- a/benchmark/fiber_chain.yml
+++ b/benchmark/fiber_chain.yml
diff --git a/benchmark/fiber_locals.yml b/benchmark/fiber_locals.yml
new file mode 100644
index 0000000000..8588686477
--- /dev/null
+++ b/benchmark/fiber_locals.yml
@@ -0,0 +1,8 @@
+prelude: |
+  th = Thread.current
+  th[:key] = :val
+benchmark:
+  key?: th.key?(:key)
+  []: th[:key]
+  keys: th.keys
+loop_count: 1_000_000
diff --git a/benchmark/file_basename.yml b/benchmark/file_basename.yml
new file mode 100644
index 0000000000..fbd78785aa
--- /dev/null
+++ b/benchmark/file_basename.yml
@@ -0,0 +1,6 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  long: File.basename("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml")
+  long_name: File.basename("Users_george_src_github.com_ruby_ruby_benchmark_file_dirname.yml")
+  withext: File.basename("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml", ".yml")
diff --git a/benchmark/file_dirname.yml b/benchmark/file_dirname.yml
new file mode 100644
index 0000000000..43a81c9371
--- /dev/null
+++ b/benchmark/file_dirname.yml
@@ -0,0 +1,6 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  long: File.dirname("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml")
+  short: File.dirname("foo/bar")
+  n_4: File.dirname("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml", 4)
diff --git a/benchmark/file_expand_path.yml b/benchmark/file_expand_path.yml
new file mode 100644
index 0000000000..9e503ab003
--- /dev/null
+++ b/benchmark/file_expand_path.yml
@@ -0,0 +1,4 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  expand_path: File.expand_path("../../foo.txt", __FILE__)
diff --git a/benchmark/file_extname.yml b/benchmark/file_extname.yml
new file mode 100644
index 0000000000..fb16e55840
--- /dev/null
+++ b/benchmark/file_extname.yml
@@ -0,0 +1,6 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  long: File.extname("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml")
+  long_name: File.extname("Users_george_src_github.com_ruby_ruby_benchmark_file_dirname.yml")
+  short: File.extname("foo/bar")
diff --git a/benchmark/file_join.yml b/benchmark/file_join.yml
new file mode 100644
index 0000000000..845257cf1e
--- /dev/null
+++ b/benchmark/file_join.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  two_strings: File.join(__FILE__, "path")
+  many_strings: File.join(__FILE__, "path", "a", "b", "c", "d")
+  array: File.join([__FILE__, "path", "a", "b", "c", "d"])
+  mixed: File.join(__FILE__, "path", "a", "b", ["c", "d"])
diff --git a/benchmark/float_methods.yml b/benchmark/float_methods.yml
new file mode 100644
index 0000000000..56ea41effc
--- /dev/null
+++ b/benchmark/float_methods.yml
@@ -0,0 +1,14 @@
+prelude: |
+  flo = 4.2
+benchmark:
+  to_f: |
+    flo.to_f
+  abs: |
+    flo.abs
+  magnitude: |
+    flo.magnitude
+  -@: |
+    -flo
+  zero?: |
+    flo.zero?
+loop_count: 20000000
diff --git a/benchmark/float_neg_posi.yml b/benchmark/float_neg_posi.yml
new file mode 100644
index 0000000000..172db1bf6d
--- /dev/null
+++ b/benchmark/float_neg_posi.yml
@@ -0,0 +1,8 @@
+prelude: |
+  flo = 4.2
+benchmark:
+  negative?: |
+    flo.negative?
+  positive?: |
+    flo.positive?
+loop_count: 20000000
diff --git a/benchmark/float_predicate.yml b/benchmark/float_predicate.yml
new file mode 100644
index 0000000000..b946937666
--- /dev/null
+++ b/benchmark/float_predicate.yml
@@ -0,0 +1,12 @@
+prelude: |
+  floats = [1.0, -1.0, 0.0, Float::NAN, Float::INFINITY, -Float::INFINITY]
+
+benchmark:
+  float_nan?: floats.each { |f| f.nan? }
+  float_finite?: floats.each { |f| f.finite? }
+  float_infinite?: floats.each { |f| f.infinite? }
+  float_zero?: floats.each { |f| f.zero? }
+  float_positive?: floats.each { |f| f.positive? }
+  float_negative?: floats.each { |f| f.negative? }
+
+loop_count: 1000000
diff --git a/benchmark/float_to_s.yml b/benchmark/float_to_s.yml
new file mode 100644
index 0000000000..0abae5cdb8
--- /dev/null
+++ b/benchmark/float_to_s.yml
@@ -0,0 +1,7 @@
+prelude: |
+  floats = [*0.0.step(1.0, 0.0001)]
+
+benchmark:
+  to_s: floats.each {|f| f.to_s}
+
+loop_count: 1000
diff --git a/benchmark/hash_aref_array.rb b/benchmark/hash_aref_array.rb
new file mode 100644
index 0000000000..ac7a683d95
--- /dev/null
+++ b/benchmark/hash_aref_array.rb
@@ -0,0 +1,5 @@
+h = {}
+arrays = (0..99).each_slice(10).to_a
+#STDERR.puts arrays.inspect
+arrays.each { |s| h[s] = s }
+200_000.times { arrays.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_str_lit.yml b/benchmark/hash_aref_str_lit.yml
new file mode 100644
index 0000000000..ed8142bcf1
--- /dev/null
+++ b/benchmark/hash_aref_str_lit.yml
@@ -0,0 +1,20 @@
+prelude: |
+  # frozen_string_literal: true
+  hash = 10.times.to_h do |i|
+    [i, i]
+  end
+  dyn_sym = "dynamic_symbol".to_sym
+  binary = RubyVM::InstructionSequence.compile("# frozen_string_literal: true\n'iseq_load'").to_binary
+  iseq_literal_string = RubyVM::InstructionSequence.load_from_binary(binary).eval
+
+  hash[:some_symbol] = 1
+  hash[dyn_sym] = 2
+  hash["small"] = 3
+  hash["frozen_string_literal"] = 4
+  hash[iseq_literal_string] = 5
+benchmark:
+  symbol: hash[:some_symbol]
+  dyn_symbol: hash[dyn_sym]
+  small_lit: hash["small"]
+  frozen_lit: hash["frozen_string_literal"]
+  iseq_lit: hash[iseq_literal_string]
diff --git a/benchmark/hash_defaults.yml b/benchmark/hash_defaults.yml
new file mode 100644
index 0000000000..833f10e1c7
--- /dev/null
+++ b/benchmark/hash_defaults.yml
@@ -0,0 +1,6 @@
+prelude: |
+  h = Hash.new { :foo }
+benchmark:
+  default_aref: h[1]
+  default_method: h.default(1)
+loop_count: 1000000
diff --git a/benchmark/hash_dup.yml b/benchmark/hash_dup.yml
new file mode 100644
index 0000000000..65f521ec94
--- /dev/null
+++ b/benchmark/hash_dup.yml
@@ -0,0 +1,8 @@
+prelude: |
+  small_hash = { a: 1 }
+  larger_hash = 20.times.map { |i| [('a'.ord + i).chr.to_sym, i] }.to_h
+
+benchmark:
+  dup_small: small_hash.dup
+  dup_larger: larger_hash.dup
+loop_count: 10000
diff --git a/benchmark/hash_first.yml b/benchmark/hash_first.yml
new file mode 100644
index 0000000000..c26df1a7ed
--- /dev/null
+++ b/benchmark/hash_first.yml
@@ -0,0 +1,11 @@
+prelude: |
+  hash1 = 1_000_000.times.to_h { [rand, true]}
+  hash2 = hash1.dup
+  hash2.keys[1..100_000].each { hash2.delete _1 }
+  hash2.delete hash2.first[0]
+
+benchmark:
+  hash1: hash1.first
+  hash2: hash2.first
+
+loop_count: 100_000
diff --git a/benchmark/hash_key.yml b/benchmark/hash_key.yml
new file mode 100644
index 0000000000..cab4cf9ca4
--- /dev/null
+++ b/benchmark/hash_key.yml
@@ -0,0 +1,5 @@
+prelude: |
+  obj = Object.new
+  hash = { obj => true }
+benchmark: hash.key?(obj)
+loop_count: 30000000
diff --git a/benchmark/hash_new.yml b/benchmark/hash_new.yml
new file mode 100644
index 0000000000..9d8e34187f
--- /dev/null
+++ b/benchmark/hash_new.yml
@@ -0,0 +1,16 @@
+prelude: |
+  has_hash_with_capa = Hash.instance_method(:initialize).parameters.include?([:key, :capacity])
+  strings_1k = 1_000.times.map { |i| -i.to_s.freeze }
+  strings_100k = 100_000.times.map { |i| -i.to_s.freeze }
+benchmark:
+  new: Hash.new
+  new_with_capa_1k: |
+    h = has_hash_with_capa ? Hash.new(capacity: strings_1k.size) : {}
+    strings_1k.each do |x|
+      h[x] = true
+    end
+  new_with_capa_100k: |
+    h = has_hash_with_capa ? Hash.new(capacity: strings_100k.size) : {}
+    strings_100k.each do |x|
+      h[x] = true
+    end
diff --git a/benchmark/int_to_s.yml b/benchmark/int_to_s.yml
new file mode 100644
index 0000000000..000dae9612
--- /dev/null
+++ b/benchmark/int_to_s.yml
@@ -0,0 +1,25 @@
+prelude: |
+  # frozen_string_literal: true
+  N1   = 5
+  N2   = 42
+  N3   = 400
+  N5   = 12345
+  N10  = 1_234_567_890
+  N19  = 4_611_686_018_427_387_903
+  NEG  = -1_234_567_890
+  BIG20  = 10 ** 19 + 12_345_678_901_234_567
+  BIG40  = 10 ** 39 + 123_456_789_012_345
+  BIG100 = 10 ** 99 + 42
+benchmark:
+  fix_1digit:   "N1.to_s"
+  fix_2digit:   "N2.to_s"
+  fix_3digit:   "N3.to_s"
+  fix_5digit:   "N5.to_s"
+  fix_10digit:  "N10.to_s"
+  fix_19digit:  "N19.to_s"
+  fix_negative: "NEG.to_s"
+  big_20digit:  "BIG20.to_s"
+  big_40digit:  "BIG40.to_s"
+  big_100digit: "BIG100.to_s"
+  interp_id:    '"id=#{N10}"'
+  interp_mixed: '"a=#{N2},b=#{N5},c=#{N10}"'
diff --git a/benchmark/integer_predicate.yml b/benchmark/integer_predicate.yml
new file mode 100644
index 0000000000..7c05ff2587
--- /dev/null
+++ b/benchmark/integer_predicate.yml
@@ -0,0 +1,9 @@
+prelude: |
+  nums = (0..9).to_a
+
+benchmark:
+  integer_zero?: nums.each { |n| n.zero? }
+  integer_even?: nums.each { |n| n.even? }
+  integer_odd?: nums.each { |n| n.odd? }
+
+loop_count: 1000000
diff --git a/benchmark/io_close.yml b/benchmark/io_close.yml
new file mode 100644
index 0000000000..a552872884
--- /dev/null
+++ b/benchmark/io_close.yml
@@ -0,0 +1,13 @@
+prelude: |
+  ios = 1000.times.map do
+    100.times.map{IO.pipe}
+  end
+benchmark:
+  # Close IO
+  io_close: |
+    # Process each batch of ios per iteration of the benchmark.
+    ios.pop.each do |r, w|
+      r.close
+      w.close
+    end
+loop_count: 100
diff --git a/benchmark/io_close_contended.yml b/benchmark/io_close_contended.yml
new file mode 100644
index 0000000000..1d9e4e0d0f
--- /dev/null
+++ b/benchmark/io_close_contended.yml
@@ -0,0 +1,21 @@
+prelude: |
+  ios = 100.times.map do
+    10.times.map do
+      pipe = IO.pipe.tap do |r, w|
+        Thread.new do
+          r.read
+        rescue IOError
+          # Ignore
+        end
+      end
+    end
+  end
+benchmark:
+  # Close IO
+  io_close_contended: |
+    # Process each batch of ios per iteration of the benchmark.
+    ios.pop.each do |r, w|
+      r.close
+      w.close
+    end
+loop_count: 10
diff --git a/benchmark/io_write.rb b/benchmark/io_write.rb
new file mode 100644
index 0000000000..cdb409948b
--- /dev/null
+++ b/benchmark/io_write.rb
@@ -0,0 +1,22 @@
+#!/usr/bin/env ruby
+
+require 'benchmark'
+
+i, o = IO.pipe
+o.sync = true
+
+DOT = ".".freeze
+
+chunks = 100_000.times.collect{DOT}
+
+thread = Thread.new do
+  while i.read(1024)
+  end
+end
+
+100.times do
+  o.write(*chunks)
+end
+
+o.close
+thread.join
diff --git a/benchmark/iseq_load_from_binary.yml b/benchmark/iseq_load_from_binary.yml
new file mode 100644
index 0000000000..7e9d73bdd4
--- /dev/null
+++ b/benchmark/iseq_load_from_binary.yml
@@ -0,0 +1,25 @@
+prelude: |
+  symbol = RubyVM::InstructionSequence.compile(":foo; :bar; :baz; :egg; :spam").to_binary
+
+  define_method = RubyVM::InstructionSequence.compile(%{
+    def foo; end
+    def bar; end
+    def baz; end
+    def egg; end
+    def spam; end
+  }).to_binary
+
+  all = RubyVM::InstructionSequence.compile(%{
+    module Foo; def foo; :foo; end; end
+    module Bar; def bar; :bar; end; end
+    module Baz; def baz; :baz; end; end
+    class Egg; def egg; :egg; end; end
+    class Spaml; def spam; :spam; end; end
+  }).to_binary
+
+benchmark:
+  symbol: RubyVM::InstructionSequence.load_from_binary(symbol)
+  define_method: RubyVM::InstructionSequence.load_from_binary(define_method)
+  all: RubyVM::InstructionSequence.load_from_binary(all)
+
+loop_count: 100_000
diff --git a/benchmark/ivar_extend.yml b/benchmark/ivar_extend.yml
new file mode 100644
index 0000000000..eb9ee923f5
--- /dev/null
+++ b/benchmark/ivar_extend.yml
@@ -0,0 +1,23 @@
+prelude: |
+  class Embedded
+    def initialize
+      @a = 1
+      @b = 1
+      @c = 1
+    end
+  end
+
+  class Extended
+    def initialize
+      @a = 1
+      @b = 1
+      @c = 1
+      @d = 1
+      @e = 1
+      @f = 1
+    end
+  end
+benchmark:
+  embedded: Embedded.new
+  extended: Extended.new
+loop_count: 20_000_000
diff --git a/benchmark/kernel_clone.yml b/benchmark/kernel_clone.yml
new file mode 100644
index 0000000000..069b23abcd
--- /dev/null
+++ b/benchmark/kernel_clone.yml
@@ -0,0 +1,6 @@
+prelude: "object = Object.new"
+benchmark:
+  clone: "object.clone"
+  clone_true: "object.clone(freeze: true)"
+  clone_false: "object.clone(freeze: false)"
+loop_count: 10000
diff --git a/benchmark/kernel_float.yml b/benchmark/kernel_float.yml
new file mode 100644
index 0000000000..215f6750fc
--- /dev/null
+++ b/benchmark/kernel_float.yml
@@ -0,0 +1,5 @@
+benchmark:
+  float: "Float(42)"
+  float_true: "Float(42, exception: true)"
+  float_false: "Float(42, exception: false)"
+loop_count: 10000
diff --git a/benchmark/kernel_tap.yml b/benchmark/kernel_tap.yml
new file mode 100644
index 0000000000..4dcbb31b4d
--- /dev/null
+++ b/benchmark/kernel_tap.yml
@@ -0,0 +1,6 @@
+prelude: |
+  obj = Object.new
+  x = nil
+benchmark:
+  kernel_tap: obj.tap { |o| x = o }
+loop_count: 20000000
diff --git a/benchmark/kernel_then.yml b/benchmark/kernel_then.yml
new file mode 100644
index 0000000000..85f7341e33
--- /dev/null
+++ b/benchmark/kernel_then.yml
@@ -0,0 +1,6 @@
+benchmark:
+  kernel_then: 1.then { |i| i + 1 }
+  kernel_then_enum: 1.then
+  kernel_yield_self: 1.yield_self { |i| i + 1 }
+  kernel_yield_self_enum: 1.yield_self
+loop_count: 20000000
diff --git a/benchmark/keyword_arguments.yml b/benchmark/keyword_arguments.yml
new file mode 100644
index 0000000000..fce6bce0b8
--- /dev/null
+++ b/benchmark/keyword_arguments.yml
@@ -0,0 +1,13 @@
+prelude: |
+  h = {a: 1}
+  def kw(a: 1) a end
+  def kws(**kw) kw end
+benchmark:
+  kw_to_kw: "kw(a: 1)"
+  kw_splat_to_kw: "kw(**h)"
+  kw_to_kw_splat: "kws(a: 1)"
+  kw_splat_to_kw_splat: "kws(**h)"
+  kw_and_splat_to_kw: "kw(a: 1, **h)"
+  kw_splats_to_kw: "kw(**h, **h)"
+  kw_and_splat_to_kw_splat: "kws(a: 1, **h)"
+  kw_splats_to_kw_splat: "kws(**h, **h)"
diff --git a/benchmark/lib/benchmark_driver/runner/mjit_exec.rb b/benchmark/lib/benchmark_driver/runner/mjit_exec.rb
deleted file mode 100644
index 9f7c8c8af3..0000000000
--- a/benchmark/lib/benchmark_driver/runner/mjit_exec.rb
+++ /dev/null
@@ -1,237 +0,0 @@
-require 'benchmark_driver/struct'
-require 'benchmark_driver/metric'
-require 'erb'
-
-# A special runner dedicated for measuring mjit_exec overhead.
-class BenchmarkDriver::Runner::MjitExec
-  METRIC = BenchmarkDriver::Metric.new(name: 'Iteration per second', unit: 'i/s')
-
-  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
-  Job = ::BenchmarkDriver::Struct.new(
-    :name,        # @param [String] name - This is mandatory for all runner
-    :metrics,     # @param [Array<BenchmarkDriver::Metric>]
-    :num_methods, # @param [Integer] num_methods - The number of methods to be defined
-    :loop_count,  # @param [Integer] loop_count
-    :from_jit,    # @param [TrueClass,FalseClass] from_jit - Whether the mjit_exec() is from JIT or not
-    :to_jit,      # @param [TrueClass,FalseClass] to_jit - Whether the mjit_exec() is to JIT or not
-  )
-  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
-  class << JobParser = Module.new
-    # @param [Array,String] num_methods
-    # @param [Integer] loop_count
-    # @param [TrueClass,FalseClass] from_jit
-    # @param [TrueClass,FalseClass] to_jit
-    def parse(num_methods:, loop_count:, from_jit:, to_jit:)
-      if num_methods.is_a?(String)
-        num_methods = eval(num_methods)
-      end
-
-      num_methods.map do |num|
-        if num_methods.size > 1
-          suffix = "[#{'%4d' % num}]"
-        else
-          suffix = "_#{num}"
-        end
-        Job.new(
-          name: "mjit_exec_#{from_jit ? 'JT' : 'VM'}2#{to_jit ? 'JT' : 'VM'}#{suffix}",
-          metrics: [METRIC],
-          num_methods: num,
-          loop_count: loop_count,
-          from_jit: from_jit,
-          to_jit: to_jit,
-        )
-      end
-    end
-  end
-
-  # @param [BenchmarkDriver::Config::RunnerConfig] config
-  # @param [BenchmarkDriver::Output] output
-  # @param [BenchmarkDriver::Context] contexts
-  def initialize(config:, output:, contexts:)
-    @config = config
-    @output = output
-    @contexts = contexts
-  end
-
-  # This method is dynamically called by `BenchmarkDriver::JobRunner.run`
-  # @param [Array<BenchmarkDriver::Runner::Peak::Job>] jobs
-  def run(jobs)
-    @output.with_benchmark do
-      jobs.each do |job|
-        @output.with_job(name: job.name) do
-          @contexts.each do |context|
-            result = BenchmarkDriver::Repeater.with_repeat(config: @config, larger_better: true, rest_on_average: :average) do
-              run_benchmark(job, context: context)
-            end
-            value, duration = result.value
-            @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
-              @output.report(values: { METRIC => value }, duration: duration, loop_count: job.loop_count)
-            end
-          end
-        end
-      end
-    end
-  end
-
-  private
-
-  # @param [BenchmarkDriver::Runner::Ips::Job] job - loop_count is not nil
-  # @param [BenchmarkDriver::Context] context
-  # @return [BenchmarkDriver::Metrics]
-  def run_benchmark(job, context:)
-    if job.from_jit
-      if job.to_jit
-        benchmark = BenchmarkJT2JT.new(num_methods: job.num_methods, loop_count: job.loop_count)
-      else
-        raise NotImplementedError, "JT2VM is not implemented yet"
-      end
-    else
-      if job.to_jit
-        benchmark = BenchmarkVM2JT.new(num_methods: job.num_methods, loop_count: job.loop_count)
-      else
-        benchmark = BenchmarkVM2VM.new(num_methods: job.num_methods, loop_count: job.loop_count)
-      end
-    end
-
-    duration = Tempfile.open(['benchmark_driver-result', '.txt']) do |f|
-      with_script(benchmark.render(result: f.path)) do |path|
-        opt = []
-        if context.executable.command.any? { |c| c.start_with?('--jit') }
-          opt << '--jit-min-calls=2'
-        end
-        IO.popen([*context.executable.command, '--disable-gems', *opt, path], &:read)
-        if $?.success?
-          Float(f.read)
-        else
-          BenchmarkDriver::Result::ERROR
-        end
-      end
-    end
-
-    [job.loop_count.to_f / duration, duration]
-  end
-
-  def with_script(script)
-    if @config.verbose >= 2
-      sep = '-' * 30
-      $stdout.puts "\n\n#{sep}[Script begin]#{sep}\n#{script}#{sep}[Script end]#{sep}\n\n"
-    end
-
-    Tempfile.open(['benchmark_driver-', '.rb']) do |f|
-      f.puts script
-      f.close
-      return yield(f.path)
-    end
-  end
-
-  # @param [Integer] num_methods
-  # @param [Integer] loop_count
-  BenchmarkVM2VM = ::BenchmarkDriver::Struct.new(:num_methods, :loop_count) do
-    # @param [String] result - A file to write result
-    def render(result:)
-      ERB.new(<<~EOS, trim_mode: '%').result(binding)
-        % num_methods.times do |i|
-        def a<%= i %>
-          nil
-        end
-        % end
-        RubyVM::MJIT.pause if RubyVM::MJIT.enabled?
-
-        def vm
-          t = Process.clock_gettime(Process::CLOCK_MONOTONIC)
-          i = 0
-          while i < <%= loop_count / 1000 %>
-        % 1000.times do |i|
-            a<%= i % num_methods %>
-        % end
-            i += 1
-          end
-        % (loop_count % 1000).times do |i|
-          a<%= i % num_methods %>
-        % end
-          Process.clock_gettime(Process::CLOCK_MONOTONIC) - t
-        end
-
-        vm # warmup call cache
-        File.write(<%= result.dump %>, vm)
-      EOS
-    end
-  end
-  private_constant :BenchmarkVM2VM
-
-  # @param [Integer] num_methods
-  # @param [Integer] loop_count
-  BenchmarkVM2JT = ::BenchmarkDriver::Struct.new(:num_methods, :loop_count) do
-    # @param [String] result - A file to write result
-    def render(result:)
-      ERB.new(<<~EOS, trim_mode: '%').result(binding)
-        % num_methods.times do |i|
-        def a<%= i %>
-          nil
-        end
-        a<%= i %>
-        a<%= i %> # --jit-min-calls=2
-        % end
-        RubyVM::MJIT.pause if RubyVM::MJIT.enabled?
-
-        def vm
-          t = Process.clock_gettime(Process::CLOCK_MONOTONIC)
-          i = 0
-          while i < <%= loop_count / 1000 %>
-        % 1000.times do |i|
-            a<%= i % num_methods %>
-        % end
-            i += 1
-          end
-        % (loop_count % 1000).times do |i|
-          a<%= i % num_methods %>
-        % end
-          Process.clock_gettime(Process::CLOCK_MONOTONIC) - t
-        end
-
-        vm # warmup call cache
-        File.write(<%= result.dump %>, vm)
-      EOS
-    end
-  end
-  private_constant :BenchmarkVM2JT
-
-  # @param [Integer] num_methods
-  # @param [Integer] loop_count
-  BenchmarkJT2JT = ::BenchmarkDriver::Struct.new(:num_methods, :loop_count) do
-    # @param [String] result - A file to write result
-    def render(result:)
-      ERB.new(<<~EOS, trim_mode: '%').result(binding)
-        % num_methods.times do |i|
-        def a<%= i %>
-          nil
-        end
-        % end
-
-        # You may need to:
-        #   * Increase `JIT_ISEQ_SIZE_THRESHOLD` to 10000000 in mjit.h
-        #   * Always return false in `inlinable_iseq_p()` of mjit_compile.c
-        def jit
-          t = Process.clock_gettime(Process::CLOCK_MONOTONIC)
-          i = 0
-          while i < <%= loop_count / 1000 %>
-        % 1000.times do |i|
-            a<%= i % num_methods %>
-        % end
-            i += 1
-          end
-        % (loop_count % 1000).times do |i|
-          a<%= i % num_methods %>
-        % end
-          Process.clock_gettime(Process::CLOCK_MONOTONIC) - t
-        end
-
-        jit
-        jit
-        RubyVM::MJIT.pause if RubyVM::MJIT.enabled?
-        File.write(<%= result.dump %>, jit)
-      EOS
-    end
-  end
-  private_constant :BenchmarkJT2JT
-end
diff --git a/benchmark/lib/benchmark_driver/runner/ractor.rb b/benchmark/lib/benchmark_driver/runner/ractor.rb
new file mode 100644
index 0000000000..fd9c2dd4db
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/ractor.rb
@@ -0,0 +1,122 @@
+require 'erb'
+
+# A runner to measure performance *inside* Ractor
+class BenchmarkDriver::Runner::Ractor < BenchmarkDriver::Runner::Ips
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob) do
+    attr_accessor :ractor
+  end
+
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC]).extend(Module.new{
+    def parse(ractor: 1, **kwargs)
+      super(**kwargs).each do |job|
+        job.ractor = ractor
+      end
+    end
+  })
+
+  private
+
+  unless private_instance_methods.include?(:run_benchmark)
+    raise "#run_benchmark is no longer defined in BenchmarkDriver::Runner::Ips"
+  end
+
+  # @param [BenchmarkDriver::Runner::Ips::Job] job - loop_count is not nil
+  # @param [BenchmarkDriver::Context] context
+  # @return [BenchmarkDriver::Metrics]
+  def run_benchmark(job, context:)
+    benchmark = BenchmarkScript.new(
+      preludes:   [context.prelude, job.prelude],
+      script:     job.script,
+      teardown:   job.teardown,
+      loop_count: job.loop_count,
+    )
+
+    results = job.ractor.times.map do
+      Tempfile.open('benchmark_driver_result')
+    end
+    duration = with_script(benchmark.render(results: results.map(&:path))) do |path|
+      success = execute(*context.executable.command, path, exception: false)
+      if success && ((value = results.map { |f| Float(f.read) }.max) > 0)
+        value
+      else
+        BenchmarkDriver::Result::ERROR
+      end
+    end
+    results.each(&:close)
+
+    value_duration(
+      loop_count: job.loop_count,
+      duration: duration,
+    )
+  end
+
+  # @param [String] prelude
+  # @param [String] script
+  # @param [String] teardown
+  # @param [Integer] loop_count
+  BenchmarkScript = ::BenchmarkDriver::Struct.new(:preludes, :script, :teardown, :loop_count) do
+    # @param [String] result - A file to write result
+    def render(results:)
+      prelude = preludes.reject(&:nil?).reject(&:empty?).join("\n")
+      ERB.new(<<-RUBY).result_with_hash(results: results)
+Warning[:experimental] = false
+# shareable-constant-value: experimental_everything
+#{prelude}
+
+if #{loop_count} == 1
+  __bmdv_loop_before = 0
+  __bmdv_loop_after = 0
+else
+  __bmdv_loop_before = Time.new
+  #{while_loop('', loop_count, id: 0)}
+  __bmdv_loop_after = Time.new
+end
+
+__bmdv_ractors = []
+<% results.size.times do %>
+__bmdv_ractors << Ractor.new(__bmdv_loop_after - __bmdv_loop_before) { |__bmdv_loop_time|
+  __bmdv_time = Time
+  __bmdv_script_before = __bmdv_time.new
+  #{while_loop(script, loop_count, id: 1)}
+  __bmdv_script_after = __bmdv_time.new
+
+  (__bmdv_script_after - __bmdv_script_before) - __bmdv_loop_time
+}
+<% end %>
+
+# Wait for all Ractors before executing code to write results
+__bmdv_ractors.map!(&:value)
+
+<% results.each do |result| %>
+File.write(<%= result.dump %>, __bmdv_ractors.shift)
+<% end %>
+
+#{teardown}
+      RUBY
+    end
+
+    private
+
+    # id is to prevent:
+    # can not isolate a Proc because it accesses outer variables (__bmdv_i)
+    def while_loop(content, times, id:)
+      if !times.is_a?(Integer) || times <= 0
+        raise ArgumentError.new("Unexpected times: #{times.inspect}")
+      elsif times == 1
+        return content
+      end
+
+      # TODO: execute in batch
+      <<-RUBY
+__bmdv_i#{id} = 0
+while __bmdv_i#{id} < #{times}
+  #{content}
+  __bmdv_i#{id} += 1
+end
+      RUBY
+    end
+  end
+  private_constant :BenchmarkScript
+end
diff --git a/benchmark/lib/load.rb b/benchmark/lib/load.rb
index 31b770c484..31b770c484 100755..100644
--- a/benchmark/lib/load.rb
+++ b/benchmark/lib/load.rb
diff --git a/benchmark/loop_each.yml b/benchmark/loop_each.yml
new file mode 100644
index 0000000000..1c757185a8
--- /dev/null
+++ b/benchmark/loop_each.yml
@@ -0,0 +1,4 @@
+prelude: |
+  arr = [nil] * 30_000_000
+benchmark:
+  loop_each: arr.each{|e|}
diff --git a/benchmark/loop_generator.rb b/benchmark/loop_generator.rb
index d3375c744c..6a3194b670 100644
--- a/benchmark/loop_generator.rb
+++ b/benchmark/loop_generator.rb
@@ -1,4 +1,4 @@
-max = 600000
+max = 6000000
 
 if defined? Fiber
   gen = (1..max).each
diff --git a/benchmark/loop_times_megamorphic.yml b/benchmark/loop_times_megamorphic.yml
new file mode 100644
index 0000000000..f9343ba897
--- /dev/null
+++ b/benchmark/loop_times_megamorphic.yml
@@ -0,0 +1,7 @@
+prelude: |
+  eval(<<~EOS)
+    def loop_times_megamorphic
+      #{"1.times {|i|};" * 1000}
+    end
+  EOS
+benchmark: loop_times_megamorphic
diff --git a/benchmark/marshal_dump_load_integer.yml b/benchmark/marshal_dump_load_integer.yml
new file mode 100644
index 0000000000..78ebf823d2
--- /dev/null
+++ b/benchmark/marshal_dump_load_integer.yml
@@ -0,0 +1,22 @@
+prelude: |
+  smallint_array = 1000.times.map { |x| x }
+  bigint32_array = 1000.times.map { |x| x + 2**32 }
+  bigint64_array = 1000.times.map { |x| x + 2**64 }
+
+  smallint_dump = Marshal.dump(smallint_array)
+  bigint32_dump = Marshal.dump(bigint32_array)
+  bigint64_dump = Marshal.dump(bigint64_array)
+benchmark:
+  marshal_dump_integer_small: |
+    Marshal.dump(smallint_array)
+  marshal_dump_integer_over_32_bit: |
+    Marshal.dump(bigint32_array)
+  marshal_dump_integer_over_64_bit: |
+    Marshal.dump(bigint64_array)
+  marshal_load_integer_small: |
+    Marshal.load(smallint_dump)
+  marshal_load_integer_over_32_bit: |
+    Marshal.load(bigint32_dump)
+  marshal_load_integer_over_64_bit: |
+    Marshal.load(bigint64_dump)
+loop_count: 4000
diff --git a/benchmark/masgn.yml b/benchmark/masgn.yml
new file mode 100644
index 0000000000..31cb8ee4a3
--- /dev/null
+++ b/benchmark/masgn.yml
@@ -0,0 +1,53 @@
+prelude: |
+  a = [nil] * 3
+  b = Class.new{attr_writer :a, :b, :c}.new
+  c = d = e = f = g = h = i = nil
+benchmark:
+  array2_2: "c = (a[0], a[1] = 1, 2)"
+  array2_3: "c = (a[0], a[1] = 1, 2, 3)"
+  array3_2: "c = (a[0], a[1], a[2] = 1, 2)"
+  array3_3: "c = (a[0], a[1], a[2] = 1, 2, 3)"
+  attr2_2: "c = (b.a, b.b = 1, 2)"
+  attr2_3: "c = (b.a, b.b = 1, 2, 3)"
+  attr3_2: "c = (b.a, b.b, b.c = 1, 2)"
+  attr3_3: "c = (b.a, b.b, b.c = 1, 2, 3)"
+  lvar2_2: "c = (d, e = 1, 2)"
+  lvar2_3: "c = (d, e = 1, 2, 3)"
+  lvar3_2: "c = (d, e, f = 1, 2)"
+  lvar3_3: "c = (d, e, f = 1, 2, 3)"
+  array2_2p: "(a[0], a[1] = 1, 2; nil)"
+  array2_3p: "(a[0], a[1] = 1, 2, 3; nil)"
+  array3_2p: "(a[0], a[1], a[2] = 1, 2; nil)"
+  array3_3p: "(a[0], a[1], a[2] = 1, 2, 3; nil)"
+  attr2_2p: "(b.a, b.b = 1, 2; nil)"
+  attr2_3p: "(b.a, b.b = 1, 2, 3; nil)"
+  attr3_2p: "(b.a, b.b, b.c = 1, 2; nil)"
+  attr3_3p: "(b.a, b.b, b.c = 1, 2, 3; nil)"
+  lvar2_2p: "(d, e = 1, 2; nil)"
+  lvar2_3p: "(d, e = 1, 2, 3; nil)"
+  lvar3_2p: "(d, e, f = 1, 2; nil)"
+  lvar3_3p: "(d, e, f = 1, 2, 3; nil)"
+  array2_2lv: "c = (a[0], a[1] = g, h)"
+  array2_ilv: "c = (a[0], a[1] = g, h, i)"
+  arrayi_2lv: "c = (a[0], a[1], a[2] = g, h)"
+  arrayi_ilv: "c = (a[0], a[1], a[2] = g, h, i)"
+  attr2_2lv: "c = (b.a, b.b = g, h)"
+  attr2_ilv: "c = (b.a, b.b = g, h, i)"
+  attri_2lv: "c = (b.a, b.b, b.c = g, h)"
+  attri_ilv: "c = (b.a, b.b, b.c = g, h, i)"
+  lvar2_2lv: "c = (d, e = g, h)"
+  lvar2_ilv: "c = (d, e = g, h, i)"
+  lvari_2lv: "c = (d, e, f = g, h)"
+  lvari_ilv: "c = (d, e, f = g, h, i)"
+  array2_2plv: "(a[0], a[1] = g, h; nil)"
+  array2_iplv: "(a[0], a[1] = g, h, i; nil)"
+  arrayi_2plv: "(a[0], a[1], a[2] = g, h; nil)"
+  arrayi_iplv: "(a[0], a[1], a[2] = g, h, i; nil)"
+  attr2_2plv: "(b.a, b.b = g, h; nil)"
+  attr2_iplv: "(b.a, b.b = g, h, i; nil)"
+  attri_2plv: "(b.a, b.b, b.c = g, h; nil)"
+  attri_iplv: "(b.a, b.b, b.c = g, h, i; nil)"
+  lvar2_2plv: "(d, e = g, h; nil)"
+  lvar2_iplv: "(d, e = g, h, i; nil)"
+  lvari_2plv: "(d, e, f = g, h; nil)"
+  lvari_iplv: "(d, e, f = g, h, i; nil)"
diff --git a/benchmark/method_bind_call.yml b/benchmark/method_bind_call.yml
new file mode 100644
index 0000000000..9e0e046ed4
--- /dev/null
+++ b/benchmark/method_bind_call.yml
@@ -0,0 +1,16 @@
+prelude: |
+  named_module = Kernel
+
+  module FakeName
+    def self.name
+      "NotMyame".freeze
+    end
+  end
+
+  MOD_NAME = Module.instance_method(:name)
+
+benchmark:
+  fastpath: MOD_NAME.bind_call(Kernel)
+  slowpath: MOD_NAME.bind_call(FakeName)
+
+loop_count: 100_000
diff --git a/benchmark/mjit_exec_jt2jt.yml b/benchmark/mjit_exec_jt2jt.yml
deleted file mode 100644
index 5be408e30c..0000000000
--- a/benchmark/mjit_exec_jt2jt.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-# Usage:
-#   RUBYOPT=-Ibenchmark/lib benchmark-driver -e 'ruby --jit' benchmark/mjit_exec_vm2jt.yml
-type: mjit_exec # benchmark/lib/benchmark_driver/runner/mjit_exec.rb
-num_methods: [1]
-#num_methods: (1..100).to_a + [200, 300, 400, 500, 600, 700, 800, 900, 1000]
-loop_count: 50000000
-from_jit: true
-to_jit: true
diff --git a/benchmark/mjit_exec_vm2jt.yml b/benchmark/mjit_exec_vm2jt.yml
deleted file mode 100644
index 9947dbb7dd..0000000000
--- a/benchmark/mjit_exec_vm2jt.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-# Usage:
-#   RUBYOPT=-Ibenchmark/lib benchmark-driver -e 'ruby --jit' benchmark/mjit_exec_vm2jt.yml
-type: mjit_exec # benchmark/lib/benchmark_driver/runner/mjit_exec.rb
-num_methods: [1]
-#num_methods: (1..100).to_a + [200, 300, 400, 500, 600, 700, 800, 900, 1000]
-loop_count: 50000000
-from_jit: false
-to_jit: true
diff --git a/benchmark/mjit_exec_vm2vm.yml b/benchmark/mjit_exec_vm2vm.yml
deleted file mode 100644
index 4b84427b10..0000000000
--- a/benchmark/mjit_exec_vm2vm.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-# Usage:
-#   RUBYOPT=-Ibenchmark/lib benchmark-driver -e 'ruby --jit' benchmark/mjit_exec_vm2vm.yml
-type: mjit_exec # benchmark/lib/benchmark_driver/runner/mjit_exec.rb
-num_methods: [1]
-#num_methods: (1..100).to_a + [200, 300, 400, 500, 600, 700, 800, 900, 1000]
-loop_count: 50000000
-from_jit: false
-to_jit: false
diff --git a/benchmark/module_eqq.yml b/benchmark/module_eqq.yml
new file mode 100644
index 0000000000..2f9c490d92
--- /dev/null
+++ b/benchmark/module_eqq.yml
@@ -0,0 +1,32 @@
+prelude: |
+  module SomeModule; end
+  class SimpleClass; end
+  class MediumClass
+    10.times { include Module.new }
+  end
+  class LargeClass
+    100.times { include Module.new }
+  end
+  class HugeClass
+    300.times { include Module.new }
+  end
+  SimpleObj = SimpleClass.new
+  MediumObj = MediumClass.new
+  LargeObj = LargeClass.new
+  HugeObj = HugeClass.new
+benchmark:
+  simple_class_eqq_simple_obj: |
+    SimpleClass === SimpleObj
+  medium_class_eqq_simple_obj: |
+    MediumClass === SimpleObj
+  simple_class_eqq_medium_obj: |
+    SimpleClass === MediumObj
+  simple_class_eqq_large_obj: |
+    SimpleClass === LargeObj
+  simple_class_eqq_huge_obj: |
+    SimpleClass === HugeObj
+  simple_class_eqq_module: |
+    SimpleClass === HugeObj
+  module_eqq_module: |
+    SomeModule === HugeObj
+loop_count: 10000000
diff --git a/benchmark/nilclass.yml b/benchmark/nilclass.yml
new file mode 100644
index 0000000000..66234c4cdf
--- /dev/null
+++ b/benchmark/nilclass.yml
@@ -0,0 +1,16 @@
+prelude: |
+  def a = nil
+benchmark:
+  rationalize:
+    nil.rationalize
+  to_c: |
+    nil.to_c
+  to_i: |
+    nil.to_i
+  to_f: |
+    nil.to_f
+  to_r: |
+    nil.to_r
+  splat: |
+    a(*nil)
+loop_count: 100000
diff --git a/benchmark/num_zero_p.yml b/benchmark/num_zero_p.yml
new file mode 100644
index 0000000000..2195963433
--- /dev/null
+++ b/benchmark/num_zero_p.yml
@@ -0,0 +1,8 @@
+benchmark:
+  - 0.zero?
+  - 1.zero?
+  - 0r.zero?
+  - 1r.zero?
+  - 0i.zero?
+  - 1i.zero?
+loop_count: 50000000
diff --git a/benchmark/numeric_methods.yml b/benchmark/numeric_methods.yml
new file mode 100644
index 0000000000..1384902935
--- /dev/null
+++ b/benchmark/numeric_methods.yml
@@ -0,0 +1,29 @@
+prelude: |
+  int = 42
+  flo = 4.2
+benchmark:
+  real?: |
+    int.real?
+  integer?: |
+    flo.integer?
+  finite?: |
+    int.finite?
+  infinite?: |
+    int.infinite?
+  integer_real: |
+    int.real
+  float_real: |
+    flo.real
+  integr_imag: |
+    int.imag
+  float_imag: |
+    flo.imag
+  integer_conj: |
+    int.conj
+  float_conj: |
+    flo.conj
+  integer_numerator: |
+    int.numerator
+  integer_denominator: |
+    int.denominator
+loop_count: 20000000
diff --git a/benchmark/object_allocate.yml b/benchmark/object_allocate.yml
new file mode 100644
index 0000000000..c6269923f0
--- /dev/null
+++ b/benchmark/object_allocate.yml
@@ -0,0 +1,49 @@
+prelude: |
+  class Eight
+    8.times { include(Module.new) }
+  end
+  class ThirtyTwo
+    32.times { include(Module.new) }
+  end
+  class SixtyFour
+    64.times { include(Module.new) }
+  end
+  class OneTwentyEight
+    128.times { include(Module.new) }
+  end
+  class OnePositional
+    def initialize a; end
+  end
+  class TwoPositional
+    def initialize a, b; end
+  end
+  class ThreePositional
+    def initialize a, b, c; end
+  end
+  class FourPositional
+    def initialize a, b, c, d; end
+  end
+  class KWArg
+    def initialize a:, b:, c:, d:
+    end
+  end
+  class Mixed
+    def initialize a, b, c:, d:
+    end
+  end
+  # Disable GC to see raw throughput:
+  GC.disable
+benchmark:
+  allocate_8_deep: Eight.new
+  allocate_32_deep: ThirtyTwo.new
+  allocate_64_deep: SixtyFour.new
+  allocate_128_deep: OneTwentyEight.new
+  allocate_1_positional_params: OnePositional.new(1)
+  allocate_2_positional_params: TwoPositional.new(1, 2)
+  allocate_3_positional_params: ThreePositional.new(1, 2, 3)
+  allocate_4_positional_params: FourPositional.new(1, 2, 3, 4)
+  allocate_kwarg_params: "KWArg.new(a: 1, b: 2, c: 3, d: 4)"
+  allocate_mixed_params: "Mixed.new(1, 2, c: 3, d: 4)"
+  allocate_no_params: "Object.new"
+  allocate_allocate: "Object.allocate"
+loop_count: 100000
diff --git a/benchmark/object_class.yml b/benchmark/object_class.yml
new file mode 100644
index 0000000000..1e5409d1e2
--- /dev/null
+++ b/benchmark/object_class.yml
@@ -0,0 +1,40 @@
+prelude: |
+  def get_class(obj)
+    i = 10_000
+    while i > 0
+      i -= 1
+      # 100 times per loop
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+    end
+  end
+
+  class Obj
+  end
+  obj = Obj.new
+
+  singleton = Obj.new
+  def singleton.bar
+  end
+
+  extended = Obj.new
+  2.times do
+    extended.extend Module.new
+  end
+
+  immediate = 1.4
+benchmark:
+  obj: get_class(obj)
+  extended: get_class(extended)
+  singleton: get_class(singleton)
+  immediate: get_class(immediate)
+loop_count: 1000
diff --git a/benchmark/object_id.yml b/benchmark/object_id.yml
new file mode 100644
index 0000000000..2bd52b923f
--- /dev/null
+++ b/benchmark/object_id.yml
@@ -0,0 +1,4 @@
+benchmark:
+  baseline: "Object.new"
+  object_id: "Object.new.object_id"
+# loop_count: 100000
diff --git a/benchmark/objspace_dump_all.yml b/benchmark/objspace_dump_all.yml
new file mode 100644
index 0000000000..ebab562d2e
--- /dev/null
+++ b/benchmark/objspace_dump_all.yml
@@ -0,0 +1,13 @@
+prelude: |
+  require 'objspace'
+  require 'tempfile'
+  $objs = 1_000.times.map { Object.new }
+  $strings = 1_000.times.map { |i| "string #{i}" }
+  $file = Tempfile.new('heap')
+  $dev_null = File.open(File::NULL, 'w+')
+
+benchmark:
+  dump_all_string: "ObjectSpace.dump_all(output: :string)"
+  dump_all_file: "ObjectSpace.dump_all(output: $file)"
+  dump_all_dev_null: "ObjectSpace.dump_all(output: $dev_null)"
+loop_count: 1
diff --git a/benchmark/pathname.yml b/benchmark/pathname.yml
new file mode 100644
index 0000000000..bcf3011eab
--- /dev/null
+++ b/benchmark/pathname.yml
@@ -0,0 +1,15 @@
+prelude: |
+  abs = Pathname("/a")
+  rel = Pathname("a")
+  p1 = Pathname.new('foo/././././bar')
+  p2 = Pathname.new('foo/bar/./../..')
+  p3 = Pathname.new('foo/bar/zot')
+benchmark:
+  p1+p2: p1+p2
+  abs.root?: abs.root?
+  rel.root?: rel.root?
+  abs.absolute?: abs.absolute?
+  rel.absolute?: rel.absolute?
+  p1.cleanpath: p1.cleanpath
+  p2.cleanpath: p2.cleanpath
+  relative_path_from: p3.relative_path_from('foo/bar/qux/quax')
diff --git a/benchmark/pm_array.yml b/benchmark/pm_array.yml
new file mode 100644
index 0000000000..babb65a289
--- /dev/null
+++ b/benchmark/pm_array.yml
@@ -0,0 +1,19 @@
+prelude: |
+  def call(*val)
+    case val
+      in [String => body]
+        [200, {}, [body]]
+      in [Integer => status]
+        [status, {}, [""]]
+      in [Integer, String] => response
+        [response[0], {}, [response[1]]]
+      in [Integer, Hash, String] => response
+        [response[0], response[1], [response[2]]]
+    end
+  end
+
+benchmark:
+  first_match: call("ok")
+  second_match: call(401)
+  third_match: call(200, "ok")
+  fourth_match: call(201, {}, "created")
diff --git a/benchmark/ractor_const.yml b/benchmark/ractor_const.yml
new file mode 100644
index 0000000000..d7ab74bdca
--- /dev/null
+++ b/benchmark/ractor_const.yml
@@ -0,0 +1,4 @@
+type: lib/benchmark_driver/runner/ractor
+benchmark:
+  ractor_const: Object
+ractor: 1
diff --git a/benchmark/ractor_float_to_s.yml b/benchmark/ractor_float_to_s.yml
new file mode 100644
index 0000000000..8f492be668
--- /dev/null
+++ b/benchmark/ractor_float_to_s.yml
@@ -0,0 +1,8 @@
+type: lib/benchmark_driver/runner/ractor
+prelude: |
+  FLOATS = [*0.0.step(1.0, 0.001)]
+benchmark:
+  ractor_float_to_s: |
+    FLOATS.each {|f| f.to_s}
+loop_count: 100
+ractor: 2
diff --git a/benchmark/ractor_string_fstring.yml b/benchmark/ractor_string_fstring.yml
new file mode 100644
index 0000000000..14b92d8fd8
--- /dev/null
+++ b/benchmark/ractor_string_fstring.yml
@@ -0,0 +1,18 @@
+type: lib/benchmark_driver/runner/ractor
+benchmark:
+  ractor_fstring_random: |
+    i = 0
+    str = "same".dup
+    while i < 2000000
+      -(i.to_s.freeze)
+      i += 1
+    end
+  ractor_fstring_same: |
+    i = 0
+    str = "same".dup
+    while i < 2000000
+      -str
+      i += 1
+    end
+loop_count: 1
+ractor: 4
diff --git a/benchmark/range_bsearch_bignum.yml b/benchmark/range_bsearch_bignum.yml
new file mode 100644
index 0000000000..5730c93fcf
--- /dev/null
+++ b/benchmark/range_bsearch_bignum.yml
@@ -0,0 +1,10 @@
+prelude: |
+  first = 2**100
+  last = 2**1000
+  mid = (first + last) / 2
+  r = first..last
+
+benchmark:
+  first: r.bsearch { |x| x >= first }
+  mid: r.bsearch { |x| x >= mid }
+  last: r.bsearch { |x| x >= last }
diff --git a/benchmark/range_bsearch_endpointless.yml b/benchmark/range_bsearch_endpointless.yml
new file mode 100644
index 0000000000..8d7bedb662
--- /dev/null
+++ b/benchmark/range_bsearch_endpointless.yml
@@ -0,0 +1,21 @@
+prelude: |
+  re = (1..)
+  rb = (..0)
+
+benchmark:
+  'endless 10**0': re.bsearch { |x| x >= 1 }
+  'endless 10**1': re.bsearch { |x| x >= 10 }
+  'endless 10**2': re.bsearch { |x| x >= 100 }
+  'endless 10**3': re.bsearch { |x| x >= 1000 }
+  'endless 10**4': re.bsearch { |x| x >= 10000 }
+  'endless 10**5': re.bsearch { |x| x >= 100000 }
+  'endless 10**10': re.bsearch { |x| x >= 10000000000 }
+  'endless 10**100': re.bsearch { |x| x >= 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 }
+  'beginless -10**0': rb.bsearch { |x| x >= -1 }
+  'beginless -10**1': rb.bsearch { |x| x >= -10 }
+  'beginless -10**2': rb.bsearch { |x| x >= -100 }
+  'beginless -10**3': rb.bsearch { |x| x >= -1000 }
+  'beginless -10**4': rb.bsearch { |x| x >= -10000 }
+  'beginless -10**5': rb.bsearch { |x| x >= -100000 }
+  'beginless -10**10': rb.bsearch { |x| x >= -10000000000 }
+  'beginless -10**100': rb.bsearch { |x| x >= -10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 }
diff --git a/benchmark/range_bsearch_fixnum.yml b/benchmark/range_bsearch_fixnum.yml
new file mode 100644
index 0000000000..59416531b9
--- /dev/null
+++ b/benchmark/range_bsearch_fixnum.yml
@@ -0,0 +1,10 @@
+prelude: |
+  first = 1
+  last = 10000
+  mid = (first + last) / 2
+  r = first..last
+
+benchmark:
+  first: r.bsearch { |x| x >= first }
+  mid: r.bsearch { |x| x >= mid }
+  last: r.bsearch { |x| x >= last }
diff --git a/benchmark/range_count.yml b/benchmark/range_count.yml
new file mode 100644
index 0000000000..58f53a0236
--- /dev/null
+++ b/benchmark/range_count.yml
@@ -0,0 +1,11 @@
+prelude: |
+  r_1 = 1..1
+  r_1k = 1..1000
+  r_1m = 1..1000000
+  r_str = 'a'..'z'
+
+benchmark:
+  'int 1': r_1.count
+  'int 1K': r_1k.count
+  'int 1M': r_1m.count
+  string: r_str.count
diff --git a/benchmark/range_min.yml b/benchmark/range_min.yml
new file mode 100644
index 0000000000..9e60dd7308
--- /dev/null
+++ b/benchmark/range_min.yml
@@ -0,0 +1,2 @@
+benchmark:
+  - (1..10).min
diff --git a/benchmark/range_overlap.yml b/benchmark/range_overlap.yml
new file mode 100644
index 0000000000..700a00053c
--- /dev/null
+++ b/benchmark/range_overlap.yml
@@ -0,0 +1,19 @@
+prelude: |
+  class Range
+    unless method_defined?(:overlap?)
+      def overlap?(other)
+        other.begin == self.begin || cover?(other.begin) || other.cover?(self.begin)
+      end
+    end
+  end
+
+benchmark:
+  - (2..3).overlap?(1..1)
+  - (2..3).overlap?(2..4)
+  - (2..3).overlap?(4..5)
+  - (2..3).overlap?(2..1)
+  - (2..3).overlap?(0..1)
+  - (2..3).overlap?(...1)
+  - (2...3).overlap?(..2)
+  - (2...3).overlap?(3...)
+  - (2..3).overlap?('a'..'d')
diff --git a/benchmark/range_reverse_each.yml b/benchmark/range_reverse_each.yml
new file mode 100644
index 0000000000..a32efeccc6
--- /dev/null
+++ b/benchmark/range_reverse_each.yml
@@ -0,0 +1,16 @@
+prelude: |
+  rf_1 = 0..1
+  rf_1k = 0..1000
+  rf_1m = 0..1000000
+  big = 2**1000
+  rb_1 = big..big+1
+  rb_1k = big..big+1000
+  rb_1m = big..big+1000000
+
+benchmark:
+  "Fixnum 1": rf_1.reverse_each { _1 }
+  "Fixnum 1K": rf_1k.reverse_each { _1 }
+  "Fixnum 1M": rf_1m.reverse_each { _1 }
+  "Bignum 1": rb_1.reverse_each { _1 }
+  "Bignum 1K": rb_1k.reverse_each { _1 }
+  "Bignum 1M": rb_1m.reverse_each { _1 }
diff --git a/benchmark/realpath.yml b/benchmark/realpath.yml
index 90a029d5b9..6b6a4836b0 100644
--- a/benchmark/realpath.yml
+++ b/benchmark/realpath.yml
@@ -12,6 +12,9 @@ prelude: |
   relative_dir = 'b/c'
   absolute_dir = File.join(pwd, relative_dir)
   file_dir = 'c'
+teardown: |
+  require 'fileutils'
+  FileUtils.rm_rf('b')
 benchmark:
   relative_nil: "f.realpath(relative, nil)"
   absolute_nil: "f.realpath(absolute, nil)"
diff --git a/benchmark/regexp_dup.yml b/benchmark/regexp_dup.yml
new file mode 100644
index 0000000000..52f89991cd
--- /dev/null
+++ b/benchmark/regexp_dup.yml
@@ -0,0 +1,6 @@
+prelude: |
+  str = "a" * 1000
+  re = Regexp.new(str)
+
+benchmark:
+  dup: re.dup
diff --git a/benchmark/regexp_new.yml b/benchmark/regexp_new.yml
new file mode 100644
index 0000000000..bc9ab3ca21
--- /dev/null
+++ b/benchmark/regexp_new.yml
@@ -0,0 +1,7 @@
+prelude: |
+  str = "a" * 1000
+  re = Regexp.new(str)
+
+benchmark:
+  string: Regexp.new(str)
+  regexp: Regexp.new(re)
diff --git a/benchmark/scan.yaml b/benchmark/scan.yaml
new file mode 100644
index 0000000000..62ad1d6862
--- /dev/null
+++ b/benchmark/scan.yaml
@@ -0,0 +1,16 @@
+prelude: |
+  $LOAD_PATH.unshift(File.expand_path("lib"))
+  require "strscan"
+  str = "test string"
+  scanner = StringScanner.new(str)
+  str = "test"
+  reg = /test/
+benchmark:
+  check(reg): |
+    scanner.check(reg)
+  check(str): |
+    scanner.check(str)
+  match?(reg): |
+    scanner.match?(reg)
+  match?(str): |
+    scanner.match?(str)
diff --git a/benchmark/search.yaml b/benchmark/search.yaml
new file mode 100644
index 0000000000..42a50c90e6
--- /dev/null
+++ b/benchmark/search.yaml
@@ -0,0 +1,16 @@
+prelude: |
+  $LOAD_PATH.unshift(File.expand_path("lib"))
+  require "strscan"
+  str = "test string"
+  scanner = StringScanner.new(str)
+  str = "string"
+  reg = /string/
+benchmark:
+  check_until(reg): |
+    scanner.check_until(reg)
+  check_until(str): |
+    scanner.check_until(str)
+  exist?(reg): |
+    scanner.exist?(reg)
+  exist?(str): |
+    scanner.exist?(str)
diff --git a/benchmark/set.yml b/benchmark/set.yml
new file mode 100644
index 0000000000..061509cb1f
--- /dev/null
+++ b/benchmark/set.yml
@@ -0,0 +1,261 @@
+prelude: |
+  # First 1000 digits of pi
+  pi = <<~END.gsub(/\D/, '')
+    31415926535897932384626433832795028841971693993751058209749445923078164062862089
+    98628034825342117067982148086513282306647093844609550582231725359408128481117450
+    28410270193852110555964462294895493038196442881097566593344612847564823378678316
+    52712019091456485669234603486104543266482133936072602491412737245870066063155881
+    74881520920962829254091715364367892590360011330530548820466521384146951941511609
+    43305727036575959195309218611738193261179310511854807446237996274956735188575272
+    48912279381830119491298336733624406566430860213949463952247371907021798609437027
+    70539217176293176752384674818467669405132000568127145263560827785771342757789609
+    17363717872146844090122495343014654958537105079227968925892354201995611212902196
+    08640344181598136297747713099605187072113499999983729780499510597317328160963185
+    95024459455346908302642522308253344685035261931188171010003137838752886587533208
+    38142061717766914730359825349042875546873115956286388235378759375195778185778053
+    21712268066130019278766111959092164201989380952572010654505906988788448549
+  END
+  array1 = 10.times.flat_map do |i|
+    pi[i...].chars.each_slice(10).map(&:join)
+  end
+  array2 = array1.map(&:reverse)
+  array1.map!(&:to_i)
+  array2.map!(&:to_i)
+  a1 = array1[...10]
+  a2 = array1[...100]
+  a3 = array1
+  oa1 = array2[...10]
+  oa2 = array2[...100]
+  oa3 = array2
+  s0 = Set.new
+  s0 = Set.new
+  s1 = Set.new(a1)
+  s2 = Set.new(a2)
+  s3 = Set.new(a3)
+  o0 = Set.new
+  o1 = Set.new(array2[...10])
+  o2 = Set.new(array2[...100])
+  o3 = Set.new(array2)
+  d0 = s0.dup
+  d1 = s1.dup
+  d2 = s2.dup
+  d3 = s3.dup
+  ss1 = s1 - a1[-1..-1]
+  ss2 = s2 - a2[-1..-1]
+  ss3 = s3 - a3[-1..-1]
+  os1 = o1 - oa1[-1..-1]
+  os2 = o2 - oa2[-1..-1]
+  os3 = o3 - oa3[-1..-1]
+  member = a1.first
+  cbi = s0.dup.compare_by_identity
+  ns = Set[s3, o3, d3]
+  set_subclass = Class.new(Set)
+
+benchmark:
+  new_0: Set.new
+  new_10: Set.new(a1)
+  new_100: Set.new(a2)
+  new_1000: Set.new(a3)
+  aref_0: Set[]
+  aref_10: Set[*a1]
+  aref_100: Set[*a2]
+  aref_1000: Set[*a3]
+  amp_0: s0 & o0
+  amp_10: s1 & o1
+  amp_100: s2 & o2
+  amp_1000: s3 & o3
+  amp_same_0: s0 & d0
+  amp_same_10: s1 & d1
+  amp_same_100: s2 & d2
+  amp_same_1000: s3 & d3
+  minus_0: s0 - o0
+  minus_10: s1 - o1
+  minus_100: s2 - o2
+  minus_1000: s3 - o3
+  minus_same_0: s0 - d0
+  minus_same_10: s1 - d1
+  minus_same_100: s2 - d2
+  minus_same_1000: s3 - d3
+  spaceship_0: s0 <=> o0
+  spaceship_diff_10: s1 <=> o1
+  spaceship_diff_100: s2 <=> o2
+  spaceship_diff_1000: s2 <=> o3
+  spaceship_sub_10: s1 <=> ss1
+  spaceship_sub_100: s2 <=> ss2
+  spaceship_sub_1000: s2 <=> ss3
+  spaceship_sup_10: ss1 <=> s1
+  spaceship_sup_100: ss2 <=> s2
+  spaceship_sup_1000: ss2 <=> s3
+  eq_0: s0 == o0
+  eq_10: s1 == o1
+  eq_100: s2 == o2
+  eq_1000: s3 == o3
+  eq_same_0: s0 == d0
+  eq_same_10: s1 == d1
+  eq_same_100: s2 == d2
+  eq_same_1000: s3 == d3
+  xor_0: s0 ^ o0
+  xor_10: s1 ^ o1
+  xor_100: s2 ^ o2
+  xor_1000: s3 ^ o3
+  xor_same_0: s0 ^ d0
+  xor_same_10: s1 ^ d1
+  xor_same_100: s2 ^ d2
+  xor_same_1000: s3 ^ d3
+  pipe_0: s0 | o0
+  pipe_10: s1 | o1
+  pipe_100: s2 | o2
+  pipe_1000: s3 | o3
+  pipe_same_0: s0 | d0
+  pipe_same_10: s1 | d1
+  pipe_same_100: s2 | d2
+  pipe_same_1000: s3 | d3
+  add: a3.each { s0.add(it) }
+  add_exist: a3.each { s3.add(it) }
+  addq: a3.each { s0.add?(it) }
+  addq_exist: a3.each { s3.add?(it) }
+  classify_0: s0.classify { it }
+  classify_10: s1.classify { it & 2 }
+  classify_100: s2.classify { it & 8 }
+  classify_1000: s3.classify { it & 32 }
+  clear: s0.clear
+  collect_0: s0.collect! { it }
+  collect_10: s1.collect! { it }
+  collect_100: s2.collect! { it }
+  collect_1000: s3.collect! { it }
+  compare_by_identity_0: s0.dup.compare_by_identity
+  compare_by_identity_10: s1.dup.compare_by_identity
+  compare_by_identity_100: s2.dup.compare_by_identity
+  compare_by_identity_1000: s3.dup.compare_by_identity
+  compare_by_identityq_false: s0.compare_by_identity?
+  compare_by_identityq_true: cbi.compare_by_identity?
+  clone_0: s0.clone
+  clone_10: s1.clone
+  clone_100: s2.clone
+  clone_1000: s3.clone
+  delete: a3.each { s3.delete(it) }
+  delete_not_exist: a3.each { o3.delete(it) }
+  deleteq: a3.each { s3.delete?(it) }
+  deleteq_not_exist: a3.each { o3.delete?(it) }
+  delete_if_0: s0.delete_if { it }
+  delete_if_10: s1.delete_if { it & 2 == 0 }
+  delete_if_100: s2.delete_if { it & 2 == 0 }
+  delete_if_1000: s3.delete_if { it & 2 == 0 }
+  disjoint_0: s0.disjoint? o0
+  disjoint_10: s1.disjoint? o1
+  disjoint_100: s2.disjoint? o2
+  disjoint_1000: s3.disjoint? o3
+  disjoint_same_0: s0.disjoint? d0
+  disjoint_same_10: s1.disjoint? d1
+  disjoint_same_100: s2.disjoint? d2
+  disjoint_same_1000: s3.disjoint? d3
+  divide_1arity_0: s0.divide { true }
+  divide_1arity_10: s1.divide { it & 2 }
+  divide_1arity_100: s2.divide { it & 8 }
+  divide_1arity_1000: s3.divide { it & 32 }
+  divide_2arity_0: s0.divide { true }
+  divide_2arity_10: s1.divide { (_1 & 2) == (_2 & 2) }
+  divide_2arity_100: s2.divide { (_1 & 8) == (_2 & 8) }
+  divide_2arity_1000: s3.divide { (_1 & 32) == (_2 & 32) }
+  dup_0: s0.dup
+  dup_10: s1.dup
+  dup_100: s2.dup
+  dup_1000: s3.dup
+  each_0: s0.each { it }
+  each_10: s1.each { it }
+  each_100: s2.each { it }
+  each_1000: s3.each { it }
+  empty_true: s0.empty?
+  empty_false: s3.empty?
+  flatten: ns.flatten
+  flattenb: ns.flatten!
+  include_true_0: s0.include? member
+  include_true_10: s1.include? member
+  include_true_100: s2.include? member
+  include_true_1000: s3.include? member
+  include_false_0: s0.include?(-1)
+  include_false_10: s1.include?(-1)
+  include_false_100: s2.include?(-1)
+  include_false_1000: s3.include?(-1)
+  intersect_0: s0.intersect? o0
+  intersect_10: s1.intersect? o1
+  intersect_100: s2.intersect? o2
+  intersect_1000: s3.intersect? o3
+  intersect_same_0: s0.intersect? d0
+  intersect_same_10: s1.intersect? d1
+  intersect_same_100: s2.intersect? d2
+  intersect_same_1000: s3.intersect? d3
+  join_0: s0.join
+  join_10: s1.join
+  join_100: s2.join
+  join_1000: s3.join
+  join_arg_0: s0.join ""
+  join_arg_10: s1.join ""
+  join_arg_100: s2.join ""
+  join_arg_1000: s3.join ""
+  keep_if_0: s0.keep_if { it }
+  keep_if_10: s1.keep_if { it & 2 == 0 }
+  keep_if_100: s2.keep_if { it & 2 == 0 }
+  keep_if_1000: s3.keep_if { it & 2 == 0 }
+  merge_set: s0.dup.merge(s3, o3)
+  merge_enum: s0.dup.merge(array1, array2)
+  proper_subset_0: s0.proper_subset? s0
+  proper_subset_10: s1.proper_subset? ss1
+  proper_subset_100: s2.proper_subset? ss2
+  proper_subset_1000: s3.proper_subset? ss3
+  proper_subset_false_10: s1.proper_subset? os1
+  proper_subset_false_100: s2.proper_subset? os2
+  proper_subset_false_1000: s3.proper_subset? os3
+  proper_superset_0: s0.proper_superset? s0
+  proper_superset_10: ss1.proper_superset? s1
+  proper_superset_100: ss2.proper_superset? s2
+  proper_superset_1000: ss3.proper_superset? s3
+  proper_superset_false_10: os1.proper_superset? s1
+  proper_superset_false_100: os2.proper_superset? s2
+  proper_superset_false_1000: os3.proper_superset? s3
+  reject_0: s0.reject! { it }
+  reject_10: s1.reject! { it & 2 == 0 }
+  reject_100: s2.reject! { it & 2 == 0 }
+  reject_1000: s3.reject! { it & 2 == 0 }
+  replace_0: s = Set.new; array1.each { s.replace(s0) }
+  replace_10: s = Set.new; array1.each { s.replace(s1) }
+  replace_100: s = Set.new; array1.each { s.replace(s2) }
+  replace_1000: s = Set.new; array1.each { s.replace(s3) }
+  reset_0: s0.reset
+  reset_10: s1.reset
+  reset_100: s2.reset
+  reset_1000: s3.reset
+  select_0: s0.select! { it }
+  select_10: s1.select! { it & 2 == 0 }
+  select_100: s2.select! { it & 2 == 0 }
+  select_1000: s3.select! { it & 2 == 0 }
+  size_0: s0.size
+  size_10: s1.size
+  size_100: s2.size
+  size_1000: s3.size
+  subtract_set: s3.dup.subtract(os3)
+  subtract_enum: s3.dup.subtract(oa3)
+  subtract_same_set: s3.dup.subtract(s3)
+  subtract_same_enum: s3.dup.subtract(a3)
+  subset_0: s0.subset? s0
+  subset_10: s1.subset? ss1
+  subset_100: s2.subset? ss2
+  subset_1000: s3.subset? ss3
+  subset_false_10: s1.subset? os1
+  subset_false_100: s2.subset? os2
+  subset_false_1000: s3.subset? os3
+  superset_0: s0.superset? s0
+  superset_10: ss1.superset? s1
+  superset_100: ss2.superset? s2
+  superset_1000: ss3.superset? s3
+  superset_false_10: os1.superset? s1
+  superset_false_100: os2.superset? s2
+  superset_false_1000: os3.superset? s3
+  to_a_0: s0.to_a
+  to_a_10: s1.to_a
+  to_a_100: s2.to_a
+  to_a_1000: s3.to_a
+  to_set_0: s0.to_set
+  to_set_10: s1.to_set
+  to_set_100: s2.to_set
+  to_set_1000: s3.to_set
diff --git a/benchmark/so_count_words.yml b/benchmark/so_count_words.yml
index 99683505f9..f7322a8541 100644
--- a/benchmark/so_count_words.yml
+++ b/benchmark/so_count_words.yml
@@ -15,13 +15,13 @@ prelude: |
   Newsgroups:   rec.games.roguelike.nethack
   X-Mailer:     Mozilla 1.1N (Macintosh; I; 68K)
 
-  Hello there, Izchak Miller was my father.  When I was younger I spent 
-  many a night, hunched over the keyboard with a cup of tea, playing 
-  nethack with him and my brother.  my dad was a philosopher with a strong 
-  weakness for fantasy/sci fi.  I remember when he started to get involved 
-  with the Nethack team- my brother's Dungeons and Dragons monster book 
-  found a regular place beside my dad's desk. it's nice to see him living 
-  on in the game he loved so much :-).  
+  Hello there,  Izchak Miller was my  father.  When I was  younger I spent
+  many  a night,  hunched over  the keyboard  with a  cup of  tea, playing
+  nethack with him and my brother.  my dad was a philosopher with a strong
+  weakness for fantasy/sci fi.  I remember when he started to get involved
+  with the  Nethack team- my  brother's Dungeons and Dragons  monster book
+  found a regular place beside my dad's  desk. it's nice to see him living
+  on in the game he loved so much :-).
                                                                     Tamar Miller
 
   The following is a really long word of 5000 characters:
@@ -38,8 +38,9 @@ prelude: |
       13.times{
         data << data
       }
-      open(wcinput, 'w'){|f| f.write data}
+      File.write(wcinput, data)
     end
+    at_exit {File.unlink(wcinput) rescue nil}
   end
 
   prepare_wc_input(wc_input_base)
@@ -49,16 +50,16 @@ benchmark:
     # $Id: wc-ruby.code,v 1.4 2004/11/13 07:43:32 bfulgham Exp $
     # http://www.bagley.org/~doug/shootout/
     # with help from Paul Brannan
-    input = open(File.join(File.dirname($0), 'wc.input'), 'rb')
 
     nl = nw = nc = 0
-    while true
-      tmp = input.read(4096) or break
-      data = tmp << (input.gets || "")
-      nc += data.length
-      nl += data.count("\n")
-      ((data.strip! || data).tr!("\n", " ") || data).squeeze!
-      nw += data.count(" ") + 1
+    File.open(File.join(File.dirname($0), 'wc.input'), 'rb') do |input|
+      while tmp = input.read(4096)
+        data = tmp << (input.gets || "")
+        nc += data.length
+        nl += data.count("\n")
+        ((data.strip! || data).tr!("\n", " ") || data).squeeze!
+        nw += data.count(" ") + 1
+      end
     end
     # STDERR.puts "#{nl} #{nw} #{nc}"
 
diff --git a/benchmark/so_meteor_contest.rb b/benchmark/so_meteor_contest.rb
index 8c136baa6c..d8c8e3ab9c 100644
--- a/benchmark/so_meteor_contest.rb
+++ b/benchmark/so_meteor_contest.rb
@@ -447,7 +447,7 @@ end
 #   as an inverse.  The inverse will ALWAYS be 3 one of the piece configurations that is exactly 3 rotations away
 #   (an odd number).  Checking even vs odd then produces a higher probability of finding more pieces earlier
 #   in the cycle.  We still need to keep checking all the permutations, but our probability of finding one will
-#   diminsh over time.  Since we are TOLD how many to search for this lets us exit before checking all pieces
+#   diminish over time.  Since we are TOLD how many to search for this lets us exit before checking all pieces
 #   this bennifit is very great when seeking small numbers of solutions and is 0 when looking for more than the
 #   maximum number
 def find_top( rotation_skip)
diff --git a/benchmark/so_nbody.rb b/benchmark/so_nbody.rb
index d6c5bb9e61..9884fc4edc 100644
--- a/benchmark/so_nbody.rb
+++ b/benchmark/so_nbody.rb
@@ -12,38 +12,38 @@ def _puts *args
 end
 
 class Planet
- attr_accessor :x, :y, :z, :vx, :vy, :vz, :mass
+  attr_accessor :x, :y, :z, :vx, :vy, :vz, :mass
 
- def initialize(x, y, z, vx, vy, vz, mass)
-  @x, @y, @z = x, y, z
-  @vx, @vy, @vz = vx * DAYS_PER_YEAR, vy * DAYS_PER_YEAR, vz * DAYS_PER_YEAR
-  @mass = mass * SOLAR_MASS
- end
-
- def move_from_i(bodies, nbodies, dt, i)
-  while i < nbodies
-   b2 = bodies[i]
-   dx = @x - b2.x
-   dy = @y - b2.y
-   dz = @z - b2.z
-
-   distance = Math.sqrt(dx * dx + dy * dy + dz * dz)
-   mag = dt / (distance * distance * distance)
-   b_mass_mag, b2_mass_mag = @mass * mag, b2.mass * mag
-
-   @vx -= dx * b2_mass_mag
-   @vy -= dy * b2_mass_mag
-   @vz -= dz * b2_mass_mag
-   b2.vx += dx * b_mass_mag
-   b2.vy += dy * b_mass_mag
-   b2.vz += dz * b_mass_mag
-   i += 1
+  def initialize(x, y, z, vx, vy, vz, mass)
+    @x, @y, @z = x, y, z
+    @vx, @vy, @vz = vx * DAYS_PER_YEAR, vy * DAYS_PER_YEAR, vz * DAYS_PER_YEAR
+    @mass = mass * SOLAR_MASS
   end
 
-  @x += dt * @vx
-  @y += dt * @vy
-  @z += dt * @vz
- end
+  def move_from_i(bodies, nbodies, dt, i)
+    while i < nbodies
+      b2 = bodies[i]
+      dx = @x - b2.x
+      dy = @y - b2.y
+      dz = @z - b2.z
+
+      distance = Math.sqrt(dx * dx + dy * dy + dz * dz)
+      mag = dt / (distance * distance * distance)
+      b_mass_mag, b2_mass_mag = @mass * mag, b2.mass * mag
+
+      @vx -= dx * b2_mass_mag
+      @vy -= dy * b2_mass_mag
+      @vz -= dz * b2_mass_mag
+      b2.vx += dx * b_mass_mag
+      b2.vy += dy * b_mass_mag
+      b2.vz += dz * b_mass_mag
+      i += 1
+    end
+
+    @x += dt * @vx
+    @y += dt * @vy
+    @z += dt * @vz
+  end
 end
 
 def energy(bodies)
diff --git a/benchmark/string_casecmp.yml b/benchmark/string_casecmp.yml
new file mode 100644
index 0000000000..88a3555c8a
--- /dev/null
+++ b/benchmark/string_casecmp.yml
@@ -0,0 +1,28 @@
+prelude: |
+  lstr1 = [*"a".."z",*"0".."9"].join("")
+  lstr10 = lstr1 * 10
+  lstr100 = lstr10 * 10
+  lstr1000 = lstr100 * 10
+  lnonascii1 = [*"\u{e0}".."\u{ff}"].join("")
+  lnonascii10 = lnonascii1 * 10
+  lnonascii100 = lnonascii10 * 10
+  lnonascii1000 = lnonascii100 * 10
+  ustr1 = [*"A".."Z",*"0".."9"].join("")
+  ustr10 = ustr1 * 10
+  ustr100 = ustr10 * 10
+  ustr1000 = ustr100 * 10
+  unonascii1 = [*"\u{c0}".."\u{df}"].join("")
+  unonascii10 = unonascii1 * 10
+  unonascii100 = unonascii10 * 10
+  unonascii1000 = unonascii100 * 10
+benchmark:
+  casecmp-1: lstr1.casecmp(ustr1)
+  casecmp-10: lstr10.casecmp(ustr10)
+  casecmp-100: lstr100.casecmp(ustr100)
+  casecmp-1000: lstr1000.casecmp(ustr1000)
+  casecmp-1000vs10: lstr1000.casecmp(ustr10)
+  casecmp-nonascii1: lnonascii1.casecmp(unonascii1)
+  casecmp-nonascii10: lnonascii10.casecmp(unonascii10)
+  casecmp-nonascii100: lnonascii100.casecmp(unonascii100)
+  casecmp-nonascii1000: lnonascii1000.casecmp(unonascii1000)
+  casecmp-nonascii1000vs10: lnonascii1000.casecmp(unonascii10)
diff --git a/benchmark/string_casecmp_p.yml b/benchmark/string_casecmp_p.yml
new file mode 100644
index 0000000000..a790ce7d55
--- /dev/null
+++ b/benchmark/string_casecmp_p.yml
@@ -0,0 +1,26 @@
+prelude: |
+  lstr1 = [*"a".."z",*"0".."9"].join("")
+  lstr10 = lstr1 * 10
+  lstr100 = lstr10 * 10
+  lstr1000 = lstr100 * 10
+  lnonascii1 = [*"\u{e0}".."\u{ff}"].join("")
+  lnonascii10 = lnonascii1 * 10
+  lnonascii100 = lnonascii10 * 10
+  lnonascii1000 = lnonascii100 * 10
+  ustr1 = [*"A".."Z",*"0".."9"].join("")
+  ustr10 = ustr1 * 10
+  ustr100 = ustr10 * 10
+  ustr1000 = ustr100 * 10
+  unonascii1 = [*"\u{c0}".."\u{df}"].join("")
+  unonascii10 = unonascii1 * 10
+  unonascii100 = unonascii10 * 10
+  unonascii1000 = unonascii100 * 10
+benchmark:
+  casecmp_p-1: lstr1.casecmp?(ustr1)
+  casecmp_p-10: lstr10.casecmp?(ustr10)
+  casecmp_p-100: lstr100.casecmp?(ustr100)
+  casecmp_p-1000: lstr1000.casecmp?(ustr1000)
+  casecmp_p-nonascii1: lnonascii1.casecmp?(unonascii1)
+  casecmp_p-nonascii10: lnonascii10.casecmp?(unonascii10)
+  casecmp_p-nonascii100: lnonascii100.casecmp?(unonascii100)
+  casecmp_p-nonascii1000: lnonascii1000.casecmp?(unonascii1000)
diff --git a/benchmark/string_codepoints.yml b/benchmark/string_codepoints.yml
new file mode 100644
index 0000000000..6a07db7ce1
--- /dev/null
+++ b/benchmark/string_codepoints.yml
@@ -0,0 +1,9 @@
+prelude: |
+  mixed_ascii64 = ("a" * 63 + "\u{100}") * 2048
+  mixed_ascii256 = ("a" * 255 + "\u{100}") * 512
+  utf8_2byte = "\u{100}" * 65536
+
+benchmark:
+  codepoints_mixed_ascii64: mixed_ascii64.codepoints
+  codepoints_mixed_ascii256: mixed_ascii256.codepoints
+  codepoints_utf8_2byte: utf8_2byte.codepoints
diff --git a/benchmark/string_coderange_scan.yml b/benchmark/string_coderange_scan.yml
new file mode 100644
index 0000000000..d47bbd2b30
--- /dev/null
+++ b/benchmark/string_coderange_scan.yml
@@ -0,0 +1,10 @@
+prelude: |
+  def unknown(s) = s.b.force_encoding("UTF-8")
+  multibyte   = unknown("\u{00e9}" * 16384)   # best case: every byte non-ASCII
+  alternating = unknown("\u{00e9}a" * 10922)  # worst case: non-ASCII then ASCII
+  ascii       = unknown("a" * 32768)          # baseline
+
+benchmark:
+  coderange_multibyte:   multibyte.dup.valid_encoding?
+  coderange_alternating: alternating.dup.valid_encoding?
+  coderange_ascii:       ascii.dup.valid_encoding?
diff --git a/benchmark/string_concat.yml b/benchmark/string_concat.yml
new file mode 100644
index 0000000000..c07fd21013
--- /dev/null
+++ b/benchmark/string_concat.yml
@@ -0,0 +1,51 @@
+prelude: |
+  CHUNK = "a" * 64
+  UCHUNK = "é" * 32
+  SHORT = "a" * (GC.stat_heap(0, :slot_size) / 2)
+  LONG = "a" * (GC.stat_heap(0, :slot_size) * 2)
+  GC.disable # GC causes a lot of variance
+benchmark:
+  binary_concat_7bit: |
+    buffer = String.new(capacity: 4096, encoding: Encoding::BINARY)
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+  utf8_concat_7bit: |
+    buffer = String.new(capacity: 4096, encoding: Encoding::UTF_8)
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+    buffer << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK << CHUNK
+  utf8_concat_UTF8: |
+    buffer = String.new(capacity: 4096, encoding: Encoding::UTF_8)
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+    buffer << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK << UCHUNK
+  interpolation: |
+    buffer = "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
+      "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}"
+  interpolation_same_heap: |
+    buffer = "#{SHORT}#{SHORT}"
+  interpolation_switching_heaps: |
+    buffer = "#{SHORT}#{LONG}"
diff --git a/benchmark/string_downcase.yml b/benchmark/string_downcase.yml
index a31c3ac712..1fea6afbec 100644
--- a/benchmark/string_downcase.yml
+++ b/benchmark/string_downcase.yml
@@ -3,8 +3,16 @@ prelude: |
   str10 = str1 * 10
   str100 = str10 * 10
   str1000 = str100 * 10
+  nonascii1 = [*"\u{c0}".."\u{df}"].join("")
+  nonascii10 = nonascii1 * 10
+  nonascii100 = nonascii10 * 10
+  nonascii1000 = nonascii100 * 10
 benchmark:
   downcase-1: str1.upcase
   downcase-10: str10.upcase
   downcase-100: str100.upcase
   downcase-1000: str1000.upcase
+  downcase-nonascii1: nonascii1.downcase
+  downcase-nonascii10: nonascii10.downcase
+  downcase-nonascii100: nonascii100.downcase
+  downcase-nonascii1000: nonascii1000.downcase
diff --git a/benchmark/string_dup.yml b/benchmark/string_dup.yml
new file mode 100644
index 0000000000..90793f9f2a
--- /dev/null
+++ b/benchmark/string_dup.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  uplus: |
+    +"A"
+  dup: |
+    "A".dup
diff --git a/benchmark/string_fstring.yml b/benchmark/string_fstring.yml
new file mode 100644
index 0000000000..cafef1f3fe
--- /dev/null
+++ b/benchmark/string_fstring.yml
@@ -0,0 +1,16 @@
+benchmark:
+  fstring_random: |
+    i = 0
+    str = "same".dup
+    while i < 5_000_000
+      -(i.to_s.freeze)
+      i += 1
+    end
+  fstring_same: |
+    i = 0
+    str = "same".dup
+    while i < 10_000_000
+      -str
+      i += 1
+    end
+loop_count: 1
diff --git a/benchmark/string_gsub.yml b/benchmark/string_gsub.yml
new file mode 100644
index 0000000000..c26e1a6498
--- /dev/null
+++ b/benchmark/string_gsub.yml
@@ -0,0 +1,54 @@
+prelude: |
+  # frozen_string_literal: true
+  STR = ((("a" * 31) + "<") * 1000).freeze
+  STR_UNICODE = ((("a" * 30) + "\u2028") * 1000).freeze
+  ESCAPED_CHARS_BINARY = {
+    "\u2028".b => '\u2028'.b,
+    "\u2029".b => '\u2029'.b,
+    ">".b => '\u003e'.b.freeze,
+    "<".b => '\u003c'.b.freeze,
+    "&".b => '\u0026'.b.freeze,
+  }
+  BINARY_PATTERN = Regexp.union(ESCAPED_CHARS_BINARY.keys)
+
+  ESCAPED_CHARS = {
+    "\u2028" => '\u2028',
+    "\u2029" => '\u2029',
+    ">" => '\u003e',
+    "<" => '\u003c',
+    "&" => '\u0026',
+  }
+  ESCAPE_PATTERN = Regexp.union(ESCAPED_CHARS.keys)
+
+  NO_MATCH_SHARED_STRING = ("a" * 100_000).freeze
+
+benchmark:
+  gsub_no_match_shared: |
+    str = NO_MATCH_SHARED_STRING.dup
+    str.gsub!("z", "x")
+    str
+
+  sub_no_match_shared: |
+    str = NO_MATCH_SHARED_STRING.dup
+    str.sub!("z", "x")
+    str
+
+  escape: |
+    str = STR.dup
+    str.gsub!(ESCAPE_PATTERN, ESCAPED_CHARS)
+    str
+
+  escape_bin: |
+    str = STR.b
+    str.gsub!(BINARY_PATTERN, ESCAPED_CHARS_BINARY)
+    str.force_encoding(Encoding::UTF_8)
+
+  escape_utf8: |
+    str = STR_UNICODE.dup
+    str.gsub!(ESCAPE_PATTERN, ESCAPED_CHARS)
+    str
+
+  escape_utf8_bin: |
+    str = STR_UNICODE.b
+    str.gsub!(BINARY_PATTERN, ESCAPED_CHARS_BINARY)
+    str.force_encoding(Encoding::UTF_8)
diff --git a/benchmark/string_inspect.yml b/benchmark/string_inspect.yml
new file mode 100644
index 0000000000..62a884e19d
--- /dev/null
+++ b/benchmark/string_inspect.yml
@@ -0,0 +1,13 @@
+prelude: |
+  ascii = "Hello, World! This is a benchmark test string." * 100
+  utf8 = "こんにちは世界。これはベンチマーク用のテスト文字列です。" * 100
+  mixed = ("Hello World! " + "テスト" + " is great! ") * 100
+  binary = ("\xE3\x81\x82" * 100).b
+  escapy = "\n\t\"\\\#" * 100
+
+benchmark:
+  inspect_ascii: ascii.inspect
+  inspect_utf8: utf8.inspect
+  inspect_mixed: mixed.inspect
+  inspect_binary: binary.inspect
+  inspect_escapy: escapy.inspect
diff --git a/benchmark/string_memsearch.yml b/benchmark/string_memsearch.yml
new file mode 100644
index 0000000000..cde363289a
--- /dev/null
+++ b/benchmark/string_memsearch.yml
@@ -0,0 +1,75 @@
+prelude: |
+  # Haystacks of various sizes
+  small_hay  = "a" * 256
+  medium_hay = "a" * 4096
+  large_hay  = "a" * 65536
+
+  # Short needles (2-8 bytes) that exercise rb_memsearch_ss
+  needle_2 = "xy"
+  needle_4 = "xyzw"
+  needle_8 = "xyzwabcd"
+
+  # Needle whose first byte is absent from the haystack (memchr fast-path)
+  # vs needle whose first byte is common (rolling hash comparison)
+  first_byte_absent  = "x" + "a" * 3
+  first_byte_common  = "a" + "x" * 3
+
+  # Haystack with match at the end
+  hay_match_end = "a" * 4095 + "xy"
+
+  # Haystack with match at the start
+  hay_match_start = "xy" + "a" * 4094
+
+  # Mixed content haystack (more realistic)
+  mixed_hay = (("abcdefghij" * 100) + "z") * 10
+
+benchmark:
+  # === First byte absent from haystack (biggest win for rolling hash) ===
+  index_first_byte_absent_small: |
+    small_hay.index(first_byte_absent)
+  index_first_byte_absent_medium: |
+    medium_hay.index(first_byte_absent)
+  index_first_byte_absent_large: |
+    large_hay.index(first_byte_absent)
+
+  # === First byte common in haystack (stresses comparison loop) ===
+  index_first_byte_common_small: |
+    small_hay.index(first_byte_common)
+  index_first_byte_common_medium: |
+    medium_hay.index(first_byte_common)
+  index_first_byte_common_large: |
+    large_hay.index(first_byte_common)
+
+  # === Needle length variations (all absent) ===
+  index_needle_2_absent: |
+    medium_hay.index(needle_2)
+  index_needle_4_absent: |
+    medium_hay.index(needle_4)
+  index_needle_8_absent: |
+    medium_hay.index(needle_8)
+
+  # === Match at end of haystack ===
+  index_match_at_end: |
+    hay_match_end.index(needle_2)
+
+  # === Match at start of haystack ===
+  index_match_at_start: |
+    hay_match_start.index(needle_2)
+
+  # === include? (same code path) ===
+  include_first_byte_absent: |
+    medium_hay.include?(first_byte_absent)
+  include_first_byte_common: |
+    medium_hay.include?(first_byte_common)
+
+  # === byteindex ===
+  byteindex_first_byte_absent: |
+    medium_hay.byteindex(first_byte_absent)
+  byteindex_first_byte_common: |
+    medium_hay.byteindex(first_byte_common)
+
+  # === Mixed/realistic haystack ===
+  index_mixed_absent: |
+    mixed_hay.index(needle_4)
+  index_mixed_present: |
+    mixed_hay.index("ijab")
diff --git a/benchmark/string_rpartition.yml b/benchmark/string_rpartition.yml
new file mode 100644
index 0000000000..37e9d1b071
--- /dev/null
+++ b/benchmark/string_rpartition.yml
@@ -0,0 +1,18 @@
+prelude: |
+  str1 = [*"a".."z",*"0".."9"].join("")
+  str10 = str1 * 10 + ":"
+  str100 = str1 * 100 + ":"
+  str1000 = str1 * 1000 + ":"
+  nonascii1 = [*"\u{e0}".."\u{ff}"].join("")
+  nonascii10 = nonascii1 * 10 + ":"
+  nonascii100 = nonascii1 * 100 + ":"
+  nonascii1000 = nonascii1 * 1000 + ":"
+benchmark:
+  rpartition-1: str1.rpartition(":")
+  rpartition-10: str10.rpartition(":")
+  rpartition-100: str100.rpartition(":")
+  rpartition-1000: str1000.rpartition(":")
+  rpartition-nonascii1: nonascii1.rpartition(":")
+  rpartition-nonascii10: nonascii10.rpartition(":")
+  rpartition-nonascii100: nonascii100.rpartition(":")
+  rpartition-nonascii1000: nonascii1000.rpartition(":")
diff --git a/benchmark/string_scrub.yml b/benchmark/string_scrub.yml
new file mode 100644
index 0000000000..4b5faaad8e
--- /dev/null
+++ b/benchmark/string_scrub.yml
@@ -0,0 +1,48 @@
+prelude: |
+
+  STRING_SIZE = 1024
+  def duplicate_to_length(str, target_length)
+    return "" if target_length <= 0
+    return str[0, target_length] if str.length >= target_length
+
+    (str * ((target_length / str.length) + 1))[0, target_length]
+  end
+  base = "Hello \u{1f600} world! \u{00e9}\u{00f1}"
+  padding = duplicate_to_length(base, STRING_SIZE)
+
+  valid_utf8 = (padding.b + "OK".b).force_encoding("UTF-8")
+  valid_utf8.valid_encoding?
+  unknown_but_valid_utf8 = valid_utf8.dup.b.force_encoding("UTF-8")
+  invalid_utf8 = (padding.b + "\x80\xFF".b).force_encoding("UTF-8")
+  invalid_utf8.valid_encoding?
+  unknown_but_invalid_utf8 = (padding.b + "\x80\xFF".b).force_encoding("UTF-8")
+
+  worst_case_utf8 = duplicate_to_length("\u{1f600}\u{00e9}\u{00f1}", STRING_SIZE).b.force_encoding("UTF-8")
+
+  unknown_but_valid_utf8_worst_case = worst_case_utf8.dup.b.force_encoding("UTF-8")
+  unknown_but_invalid_utf8_worst_case = (worst_case_utf8.b + "\x80\xFF".b).force_encoding("UTF-8")
+
+benchmark:
+  scrub_known_valid: |
+    string = valid_utf8.dup
+    string.scrub!
+
+  scrub_known_invalid: |
+    string = invalid_utf8.dup
+    string.scrub!
+
+  scrub_unknown_but_valid_coderange: |
+    string = unknown_but_valid_utf8.dup
+    string.scrub!
+
+  scrub_unknown_and_invalid_coderange: |
+    string = unknown_but_invalid_utf8.dup
+    string.scrub!
+
+  scrub_unknown_but_valid_coderange_worst_case: |
+    string = unknown_but_valid_utf8_worst_case.dup
+    string.scrub!
+
+  scrub_unknown_and_invalid_coderange_worst_case: |
+    string = unknown_but_invalid_utf8_worst_case.dup
+    string.scrub!
+\ No newline at end of file
diff --git a/benchmark/string_slice.yml b/benchmark/string_slice.yml
new file mode 100644
index 0000000000..fc2393c5d1
--- /dev/null
+++ b/benchmark/string_slice.yml
@@ -0,0 +1,11 @@
+prelude: |
+  long_string = "x"*1000+"-hår"
+benchmark:
+  regexp-short: |
+    "x-hår".slice!(/-(.)(.)(.)/, 3)
+  regexp-long: |
+    long_string.dup.slice!(/-(.)(.)(.)/, 3)
+  string-short: |
+    "x-hår".slice!("r")
+  string-long: |
+    long_string.dup.slice!("r")
diff --git a/benchmark/string_split.yml b/benchmark/string_split.yml
index 84ffe8f6a7..cc2c7d7855 100644
--- a/benchmark/string_split.yml
+++ b/benchmark/string_split.yml
@@ -1,7 +1,22 @@
 prelude: |
-  str0 = [*0..9].join("")
+  str1 = [*0..5].join(" ") + " "
+  str10 = str1 * 10
+  str100 = str10 * 10
+  str1000 = str100 * 10
 benchmark:
-  to_chars-1: str0.split('')
-  to_chars-10: (str0 * 10).split('')
-  to_chars-100: (str0 * 100).split('')
-  to_chars-1000: (str0 * 1000).split('')
+  to_chars-1: str1.split('')
+  to_chars-10: str10.split('')
+  to_chars-100: str100.split('')
+  to_chars-1000: str1000.split('')
+  to_words-1: str1.split(' ')
+  to_words-10: str10.split(' ')
+  to_words-100: str100.split(' ')
+  to_words-1000: str1000.split(' ')
+  re_chars-1: str1.split(//)
+  re_chars-10: str10.split(//)
+  re_chars-100: str100.split(//)
+  re_chars-1000: str1000.split(//)
+  re_space-1: str1.split(/ /)
+  re_space-10: str10.split(/ /)
+  re_space-100: str100.split(/ /)
+  re_space-1000: str1000.split(/ /)
diff --git a/benchmark/string_swapcase.yml b/benchmark/string_swapcase.yml
index afaae3f696..eeb5928907 100644
--- a/benchmark/string_swapcase.yml
+++ b/benchmark/string_swapcase.yml
@@ -3,8 +3,16 @@ prelude: |
   str10 = str1 * 10
   str100 = str10 * 10
   str1000 = str100 * 10
+  nonascii1 = [*"\u{c0}".."\u{cf}",*"\u{f0}".."\u{ff}"].join("")
+  nonascii10 = nonascii1 * 10
+  nonascii100 = nonascii10 * 10
+  nonascii1000 = nonascii100 * 10
 benchmark:
   swapcase-1: str1.swapcase
   swapcase-10: str10.swapcase
   swapcase-100: str100.swapcase
   swapcase-1000: str1000.swapcase
+  swapcase-nonascii1: nonascii1.swapcase
+  swapcase-nonascii10: nonascii10.swapcase
+  swapcase-nonascii100: nonascii100.swapcase
+  swapcase-nonascii1000: nonascii1000.swapcase
diff --git a/benchmark/string_upcase.yml b/benchmark/string_upcase.yml
index 456d213c74..dab84bbde2 100644
--- a/benchmark/string_upcase.yml
+++ b/benchmark/string_upcase.yml
@@ -3,8 +3,16 @@ prelude: |
   str10 = str1 * 10
   str100 = str10 * 10
   str1000 = str100 * 10
+  nonascii1 = [*"\u{e0}".."\u{ff}"].join("")
+  nonascii10 = nonascii1 * 10
+  nonascii100 = nonascii10 * 10
+  nonascii1000 = nonascii100 * 10
 benchmark:
   upcase-1: str1.upcase
   upcase-10: str10.upcase
   upcase-100: str100.upcase
   upcase-1000: str1000.upcase
+  upcase-nonascii1: nonascii1.upcase
+  upcase-nonascii10: nonascii10.upcase
+  upcase-nonascii100: nonascii100.upcase
+  upcase-nonascii1000: nonascii1000.upcase
diff --git a/benchmark/struct_accessor.yml b/benchmark/struct_accessor.yml
new file mode 100644
index 0000000000..d95240e2dd
--- /dev/null
+++ b/benchmark/struct_accessor.yml
@@ -0,0 +1,37 @@
+prelude: |
+  C = Struct.new(:x) do
+    def initialize(...)
+      super
+      @ivar = 42
+    end
+
+    attr_accessor :ivar
+
+    class_eval <<-END
+      def r
+        #{'x;'*256}
+      end
+      def w
+        #{'self.x = nil;'*256}
+      end
+      def rm
+        m = method(:x)
+        #{'m.call;'*256}
+      end
+      def wm
+        m = method(:x=)
+        #{'m.call(nil);'*256}
+      end
+      def r_ivar
+        #{'ivar;'*256}
+      end
+    END
+  end
+  C.new(nil) # ensure common shape is known
+  obj = C.new(nil)
+benchmark:
+  member_reader: "obj.r"
+  member_writer: "obj.w"
+  member_reader_method: "obj.rm"
+  member_writer_method: "obj.wm"
+  ivar_reader: "obj.r_ivar"
diff --git a/benchmark/time_at.yml b/benchmark/time_at.yml
new file mode 100644
index 0000000000..3247efbe77
--- /dev/null
+++ b/benchmark/time_at.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  - 'Time.at(0)'
+  - 'Time.at(0, 500)'
+  - 'Time.at(0, in: "+09:00")'
+  - 'Time.at(0, 500, in: "+09:00")'
diff --git a/benchmark/time_new.yml b/benchmark/time_new.yml
new file mode 100644
index 0000000000..5947dd3a41
--- /dev/null
+++ b/benchmark/time_new.yml
@@ -0,0 +1,4 @@
+benchmark:
+  - 'Time.new(2021)'
+  - 'Time.new(2021, 8, 22)'
+  - 'Time.new(2021, 8, 22, in: "+09:00")'
diff --git a/benchmark/time_now.yml b/benchmark/time_now.yml
new file mode 100644
index 0000000000..9336877cd4
--- /dev/null
+++ b/benchmark/time_now.yml
@@ -0,0 +1,4 @@
+benchmark:
+  - 'Time.now'
+  - 'Time.now(in: "+09:00")'
+  - 'Time.now.year'
diff --git a/benchmark/time_parse.yml b/benchmark/time_parse.yml
new file mode 100644
index 0000000000..6060b58bc6
--- /dev/null
+++ b/benchmark/time_parse.yml
@@ -0,0 +1,10 @@
+prelude: |
+  require 'time'
+  inspect = "2021-08-23 09:57:02 +0900"
+  iso8601 = "2021-08-23T09:57:02+09:00"
+benchmark:
+  - Time.iso8601(iso8601)
+  - Time.parse(iso8601)
+  - Time.parse(inspect)
+  - Time.new(iso8601) rescue Time.iso8601(iso8601)
+  - Time.new(inspect) rescue Time.parse(inspect)
diff --git a/benchmark/time_strftime.yml b/benchmark/time_strftime.yml
new file mode 100644
index 0000000000..28f62aec87
--- /dev/null
+++ b/benchmark/time_strftime.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+  time = Time.now
+benchmark:
+  - time.strftime("%FT%T")     # 19B
+  - time.strftime("%FT%T.%3N") # 23B
+  - time.strftime("%FT%T.%6N") # 26B
diff --git a/benchmark/time_xmlschema.yml b/benchmark/time_xmlschema.yml
new file mode 100644
index 0000000000..654e5cfcbc
--- /dev/null
+++ b/benchmark/time_xmlschema.yml
@@ -0,0 +1,27 @@
+prelude: |
+  # frozen_string_literal
+  unless Time.method_defined?(:xmlschema)
+    class Time
+      def xmlschema(fraction_digits=0)
+        fraction_digits = fraction_digits.to_i
+        s = strftime("%FT%T")
+        if fraction_digits > 0
+          s << strftime(".%#{fraction_digits}N")
+        end
+        s << (utc? ? 'Z' : strftime("%:z"))
+      end
+    end
+  end
+  time = Time.now
+  utc_time = Time.now.utc
+  fraction_sec = Time.at(123456789.quo(9999999999)).getlocal("+09:00")
+  future_time = Time.utc(10000)
+benchmark:
+  - time.xmlschema
+  - utc_time.xmlschema
+  - time.xmlschema(6)
+  - utc_time.xmlschema(6)
+  - time.xmlschema(9)
+  - utc_time.xmlschema(9)
+  - fraction_sec.xmlschema(10)
+  - future_time.xmlschema
diff --git a/benchmark/vm1_attr_ivar.yml b/benchmark/vm1_attr_ivar.yml
deleted file mode 100644
index f714dd9bd9..0000000000
--- a/benchmark/vm1_attr_ivar.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-prelude: |
-  class C
-    attr_reader :a, :b
-    def initialize
-      @a = nil
-      @b = nil
-    end
-  end
-  obj = C.new
-benchmark:
-  vm1_attr_ivar: |
-    j = obj.a
-    k = obj.b
-loop_count: 30000000
diff --git a/benchmark/vm1_attr_ivar_set.yml b/benchmark/vm1_attr_ivar_set.yml
deleted file mode 100644
index f383e59ef4..0000000000
--- a/benchmark/vm1_attr_ivar_set.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-prelude: |
-  class C
-    attr_accessor :a, :b
-    def initialize
-      @a = nil
-      @b = nil
-    end
-  end
-  obj = C.new
-benchmark:
-  vm1_attr_ivar_set: |
-    obj.a = 1
-    obj.b = 2
-loop_count: 30000000
diff --git a/benchmark/vm1_block.yml b/benchmark/vm1_block.yml
deleted file mode 100644
index ac7c940f93..0000000000
--- a/benchmark/vm1_block.yml
+++ /dev/null
@@ -1,9 +0,0 @@
-prelude: |
-  def m
-    yield
-  end
-benchmark:
-  vm1_block: |
-    m{
-    }
-loop_count: 30000000
diff --git a/benchmark/vm1_blockparam.yml b/benchmark/vm1_blockparam.yml
deleted file mode 100644
index 947b8c53d5..0000000000
--- a/benchmark/vm1_blockparam.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  def m &b
-  end
-benchmark:
-  vm1_blockparam: |
-    m{}
-loop_count: 30000000
diff --git a/benchmark/vm1_blockparam_call.yml b/benchmark/vm1_blockparam_call.yml
deleted file mode 100644
index e2817a3ce2..0000000000
--- a/benchmark/vm1_blockparam_call.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  def m &b
-    b.call
-  end
-benchmark:
-  vm1_blockparam_call: |
-    m{}
-loop_count: 30000000
diff --git a/benchmark/vm1_blockparam_pass.yml b/benchmark/vm1_blockparam_pass.yml
deleted file mode 100644
index ca1bef3369..0000000000
--- a/benchmark/vm1_blockparam_pass.yml
+++ /dev/null
@@ -1,12 +0,0 @@
-prelude: |
-  def bp_yield
-    yield
-  end
-
-  def bp_pass &b
-    bp_yield &b
-  end
-benchmark:
-  vm1_blockparam_pass: |
-    bp_pass{}
-loop_count: 30000000
diff --git a/benchmark/vm1_blockparam_yield.yml b/benchmark/vm1_blockparam_yield.yml
deleted file mode 100644
index 56ae617798..0000000000
--- a/benchmark/vm1_blockparam_yield.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  def bp_yield &b
-    yield
-  end
-benchmark:
-  vm1_blockparam_yield: |
-    bp_yield{}
-loop_count: 30000000
diff --git a/benchmark/vm1_const.yml b/benchmark/vm1_const.yml
deleted file mode 100644
index b98db1545c..0000000000
--- a/benchmark/vm1_const.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  Const = 1
-benchmark:
-  vm1_const: |
-    j = Const
-    k = Const
-loop_count: 30000000
diff --git a/benchmark/vm1_ensure.yml b/benchmark/vm1_ensure.yml
deleted file mode 100644
index afbbe38bec..0000000000
--- a/benchmark/vm1_ensure.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-# Not utilizing loop_count since using it for this is too unstable for now
-benchmark:
-  vm1_ensure: |
-    i = 0
-    while i<30_000_000
-      i += 1
-      begin
-        begin
-        ensure
-        end
-      ensure
-      end
-    end
-loop_count: 1
diff --git a/benchmark/vm1_float_simple.yml b/benchmark/vm1_float_simple.yml
deleted file mode 100644
index 4e9ad1852b..0000000000
--- a/benchmark/vm1_float_simple.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  f = 0.0
-benchmark:
-  vm1_float_simple: |
-    f += 0.1; f -= 0.1
-    f += 0.1; f -= 0.1
-    f += 0.1; f -= 0.1
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_short_lived.yml b/benchmark/vm1_gc_short_lived.yml
deleted file mode 100644
index 8fdcb7371d..0000000000
--- a/benchmark/vm1_gc_short_lived.yml
+++ /dev/null
@@ -1,9 +0,0 @@
-benchmark:
-  vm1_gc_short_lived: |
-    a = '' # short-lived String
-    b = ''
-    c = ''
-    d = ''
-    e = ''
-    f = ''
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_short_with_complex_long.yml b/benchmark/vm1_gc_short_with_complex_long.yml
deleted file mode 100644
index c22ea74a60..0000000000
--- a/benchmark/vm1_gc_short_with_complex_long.yml
+++ /dev/null
@@ -1,25 +0,0 @@
-prelude: |
-  def nested_hash h, n
-    if n == 0
-      ''
-    else
-      10.times{
-        h[Object.new] = nested_hash(h, n-1)
-      }
-    end
-  end
-
-  long_lived = Hash.new
-  nested_hash long_lived, 6
-
-  GC.start
-  GC.start
-benchmark:
-  vm1_gc_short_with_complex_long: |
-    a = '' # short-lived String
-    b = ''
-    c = ''
-    d = ''
-    e = ''
-    f = ''
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_short_with_long.yml b/benchmark/vm1_gc_short_with_long.yml
deleted file mode 100644
index c731aae548..0000000000
--- a/benchmark/vm1_gc_short_with_long.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-prelude: |
-  long_lived = Array.new(1_000_000){|i| "#{i}"}
-  GC.start
-  GC.start
-benchmark:
-  vm1_gc_short_with_long: |
-    a = '' # short-lived String
-    b = ''
-    c = ''
-    d = ''
-    e = ''
-    f = ''
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_short_with_symbol.yml b/benchmark/vm1_gc_short_with_symbol.yml
deleted file mode 100644
index 7fc1abedd8..0000000000
--- a/benchmark/vm1_gc_short_with_symbol.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-prelude: |
-  50_000.times{|i| sym = "sym#{i}".to_sym}
-  GC.start
-  GC.start
-benchmark:
-  vm1_gc_short_with_symbol: |
-    a = '' # short-lived String
-    b = ''
-    c = ''
-    d = ''
-    e = ''
-    f = ''
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_wb_ary.yml b/benchmark/vm1_gc_wb_ary.yml
deleted file mode 100644
index 50fb4b6f84..0000000000
--- a/benchmark/vm1_gc_wb_ary.yml
+++ /dev/null
@@ -1,12 +0,0 @@
-prelude: |
-  short_lived_ary = []
-
-  if RUBY_VERSION >= "2.2.0"
-    GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true)
-  end
-
-  short_lived = ''
-benchmark:
-  vm1_gc_wb_ary: |
-    short_lived_ary[0] = short_lived # write barrier
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_wb_ary_promoted.yml b/benchmark/vm1_gc_wb_ary_promoted.yml
deleted file mode 100644
index cf9b5de005..0000000000
--- a/benchmark/vm1_gc_wb_ary_promoted.yml
+++ /dev/null
@@ -1,15 +0,0 @@
-prelude: |
-  long_lived = []
-
-  if RUBY_VERSION > "2.2.0"
-    3.times{ GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true) }
-  elsif
-    GC.start
-  end
-
-  short_lived = ''
-
-benchmark:
-  vm1_gc_wb_ary_promoted: |
-    long_lived[0] = short_lived # write barrier
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_wb_obj.yml b/benchmark/vm1_gc_wb_obj.yml
deleted file mode 100644
index 9dc08e7e1a..0000000000
--- a/benchmark/vm1_gc_wb_obj.yml
+++ /dev/null
@@ -1,15 +0,0 @@
-prelude: |
-  class C
-    attr_accessor :foo
-  end
-  short_lived_obj = C.new
-
-  if RUBY_VERSION >= "2.2.0"
-    GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true)
-  end
-
-  short_lived = ''
-benchmark:
-  vm1_gc_wb_obj: |
-    short_lived_obj.foo = short_lived # write barrier
-loop_count: 30000000
diff --git a/benchmark/vm1_gc_wb_obj_promoted.yml b/benchmark/vm1_gc_wb_obj_promoted.yml
deleted file mode 100644
index 26859d2a52..0000000000
--- a/benchmark/vm1_gc_wb_obj_promoted.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-prelude: |
-  class C
-    attr_accessor :foo
-  end
-  long_lived = C.new
-
-  if RUBY_VERSION >= "2.2.0"
-    3.times{ GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true) }
-  elsif
-    GC.start
-  end
-
-  short_lived = ''
-benchmark:
-  vm1_gc_wb_obj_promoted: |
-    long_lived.foo = short_lived # write barrier
-loop_count: 30000000
diff --git a/benchmark/vm1_ivar.yml b/benchmark/vm1_ivar.yml
deleted file mode 100644
index 7aa6fac729..0000000000
--- a/benchmark/vm1_ivar.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-prelude: "@a = 1\n"
-benchmark:
-  vm1_ivar: |
-    j = @a
-    k = @a
-loop_count: 30000000
diff --git a/benchmark/vm1_ivar_set.yml b/benchmark/vm1_ivar_set.yml
deleted file mode 100644
index 6f19412d16..0000000000
--- a/benchmark/vm1_ivar_set.yml
+++ /dev/null
@@ -1,5 +0,0 @@
-benchmark:
-  vm1_ivar_set: |
-    @a = 1
-    @b = 2
-loop_count: 30000000
diff --git a/benchmark/vm1_length.yml b/benchmark/vm1_length.yml
deleted file mode 100644
index a18e2ca2e6..0000000000
--- a/benchmark/vm1_length.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  a = 'abc'
-  b = [1, 2, 3]
-benchmark:
-  vm1_length: |
-    a.length
-    b.length
-loop_count: 30000000
diff --git a/benchmark/vm1_lvar_init.yml b/benchmark/vm1_lvar_init.yml
deleted file mode 100644
index 10e2becef9..0000000000
--- a/benchmark/vm1_lvar_init.yml
+++ /dev/null
@@ -1,21 +0,0 @@
-# while loop cost is not removed because `i` is used in the script
-benchmark:
-  vm1_lvar_init: |
-    def m v
-      unless v
-        # unreachable code
-        v1 = v2 = v3 = v4 = v5 = v6 = v7 = v8 = v9 = v10 =
-        v11 = v12 = v13 = v14 = v15 = v16 = v17 = v18 = v19 = v20 =
-        v21 = v22 = v23 = v24 = v25 = v26 = v27 = v28 = v29 = v30 =
-        v31 = v32 = v33 = v34 = v35 = v36 = v37 = v38 = v39 = v40 =
-        v41 = v42 = v43 = v44 = v45 = v46 = v47 = v48 = v49 = v50 = 1
-      end
-    end
-
-    i = 0
-
-    while i<30_000_000
-      i += 1
-      m i
-    end
-loop_count: 1
diff --git a/benchmark/vm1_lvar_set.yml b/benchmark/vm1_lvar_set.yml
deleted file mode 100644
index df8f6b6ea4..0000000000
--- a/benchmark/vm1_lvar_set.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm1_lvar_set: |
-    a = b = c = d = e = f = g = h = j = k = l = m = n = o = p = q = r = 1
-loop_count: 30000000
diff --git a/benchmark/vm1_neq.yml b/benchmark/vm1_neq.yml
deleted file mode 100644
index 65a8128dda..0000000000
--- a/benchmark/vm1_neq.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  obj1 = Object.new
-  obj2 = Object.new
-benchmark:
-  vm1_neq: |
-    obj1 != obj2
-loop_count: 30000000
diff --git a/benchmark/vm1_not.yml b/benchmark/vm1_not.yml
deleted file mode 100644
index 0fb7b282a9..0000000000
--- a/benchmark/vm1_not.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-prelude: |
-  obj = Object.new
-benchmark:
-  vm1_not: |
-    !obj
-loop_count: 30000000
diff --git a/benchmark/vm1_rescue.yml b/benchmark/vm1_rescue.yml
deleted file mode 100644
index a175b823af..0000000000
--- a/benchmark/vm1_rescue.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-benchmark:
-  vm1_rescue: |
-    begin
-    rescue
-    end
-loop_count: 30000000
diff --git a/benchmark/vm1_simplereturn.yml b/benchmark/vm1_simplereturn.yml
deleted file mode 100644
index 3564aac7e2..0000000000
--- a/benchmark/vm1_simplereturn.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  def m
-    return 1
-  end
-benchmark:
-  vm1_simplereturn: m
-loop_count: 30000000
diff --git a/benchmark/vm1_swap.yml b/benchmark/vm1_swap.yml
deleted file mode 100644
index fed87ccd62..0000000000
--- a/benchmark/vm1_swap.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  a = 1
-  b = 2
-benchmark:
-  vm1_swap: |
-    a, b = b, a
-loop_count: 30000000
diff --git a/benchmark/vm1_yield.yml b/benchmark/vm1_yield.yml
deleted file mode 100644
index ae1f9316f9..0000000000
--- a/benchmark/vm1_yield.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-# while loop cost is not removed due to benchmark_driver.gem's limitation
-benchmark:
-  vm1_yield: |
-    def m
-      i = 0
-      while i<30_000_000
-        i += 1
-        yield
-      end
-    end
-
-    m{}
-loop_count: 1
diff --git a/benchmark/vm2_array.yml b/benchmark/vm2_array.yml
deleted file mode 100644
index 7373098d5e..0000000000
--- a/benchmark/vm2_array.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm2_array: |
-    a = [1,2,3,4,5,6,7,8,9,10]
-loop_count: 6000000
diff --git a/benchmark/vm2_bigarray.yml b/benchmark/vm2_bigarray.yml
deleted file mode 100644
index 2ad6da3905..0000000000
--- a/benchmark/vm2_bigarray.yml
+++ /dev/null
@@ -1,105 +0,0 @@
-benchmark:
-  vm2_bigarray: |
-    a = [
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-      1,2,3,4,5,6,7,8,9,10,
-    ]
-loop_count: 6000000
diff --git a/benchmark/vm2_bighash.yml b/benchmark/vm2_bighash.yml
deleted file mode 100644
index e9154e4ba9..0000000000
--- a/benchmark/vm2_bighash.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm2_bighash: |
-    a = {0=>0, 1=>1, 2=>2, 3=>3, 4=>4, 5=>5, 6=>6, 7=>7, 8=>8, 9=>9, 10=>10, 11=>11, 12=>12, 13=>13, 14=>14, 15=>15, 16=>16, 17=>17, 18=>18, 19=>19, 20=>20, 21=>21, 22=>22, 23=>23, 24=>24, 25=>25, 26=>26, 27=>27, 28=>28, 29=>29, 30=>30, 31=>31, 32=>32, 33=>33, 34=>34, 35=>35, 36=>36, 37=>37, 38=>38, 39=>39, 40=>40, 41=>41, 42=>42, 43=>43, 44=>44, 45=>45, 46=>46, 47=>47, 48=>48, 49=>49, 50=>50, 51=>51, 52=>52, 53=>53, 54=>54, 55=>55, 56=>56, 57=>57, 58=>58, 59=>59, 60=>60, 61=>61, 62=>62, 63=>63, 64=>64, 65=>65, 66=>66, 67=>67, 68=>68, 69=>69, 70=>70, 71=>71, 72=>72, 73=>73, 74=>74, 75=>75, 76=>76, 77=>77, 78=>78, 79=>79, 80=>80, 81=>81, 82=>82, 83=>83, 84=>84, 85=>85, 86=>86, 87=>87, 88=>88, 89=>89, 90=>90, 91=>91, 92=>92, 93=>93, 94=>94, 95=>95, 96=>96, 97=>97, 98=>98, 99=>99, 100=>100, 101=>101, 102=>102, 103=>103, 104=>104, 105=>105, 106=>106, 107=>107, 108=>108, 109=>109, 110=>110, 111=>111, 112=>112, 113=>113, 114=>114, 115=>115, 116=>116, 117=>117, 118=>118, 119=>119, 120=>120, 121=>121, 122=>122, 123=>123, 124=>124, 125=>125, 126=>126, 127=>127, 128=>128, 129=>129, 130=>130, 131=>131, 132=>132, 133=>133, 134=>134, 135=>135, 136=>136, 137=>137, 138=>138, 139=>139, 140=>140, 141=>141, 142=>142, 143=>143, 144=>144, 145=>145, 146=>146, 147=>147, 148=>148, 149=>149, 150=>150, 151=>151, 152=>152, 153=>153, 154=>154, 155=>155, 156=>156, 157=>157, 158=>158, 159=>159, 160=>160, 161=>161, 162=>162, 163=>163, 164=>164, 165=>165, 166=>166, 167=>167, 168=>168, 169=>169, 170=>170, 171=>171, 172=>172, 173=>173, 174=>174, 175=>175, 176=>176, 177=>177, 178=>178, 179=>179, 180=>180, 181=>181, 182=>182, 183=>183, 184=>184, 185=>185, 186=>186, 187=>187, 188=>188, 189=>189, 190=>190, 191=>191, 192=>192, 193=>193, 194=>194, 195=>195, 196=>196, 197=>197, 198=>198, 199=>199, 200=>200, 201=>201, 202=>202, 203=>203, 204=>204, 205=>205, 206=>206, 207=>207, 208=>208, 209=>209, 210=>210, 211=>211, 212=>212, 213=>213, 214=>214, 215=>215, 216=>216, 217=>217, 218=>218, 219=>219, 220=>220, 221=>221, 222=>222, 223=>223, 224=>224, 225=>225, 226=>226, 227=>227, 228=>228, 229=>229, 230=>230, 231=>231, 232=>232, 233=>233, 234=>234, 235=>235, 236=>236, 237=>237, 238=>238, 239=>239, 240=>240, 241=>241, 242=>242, 243=>243, 244=>244, 245=>245, 246=>246, 247=>247, 248=>248, 249=>249, 250=>250, 251=>251, 252=>252, 253=>253, 254=>254, 255=>255, 256=>256, 257=>257, 258=>258, 259=>259, 260=>260, 261=>261, 262=>262, 263=>263, 264=>264, 265=>265, 266=>266, 267=>267, 268=>268, 269=>269, 270=>270, 271=>271, 272=>272, 273=>273, 274=>274, 275=>275, 276=>276, 277=>277, 278=>278, 279=>279, 280=>280, 281=>281, 282=>282, 283=>283, 284=>284, 285=>285, 286=>286, 287=>287, 288=>288, 289=>289, 290=>290, 291=>291, 292=>292, 293=>293, 294=>294, 295=>295, 296=>296, 297=>297, 298=>298, 299=>299, 300=>300, 301=>301, 302=>302, 303=>303, 304=>304, 305=>305, 306=>306, 307=>307, 308=>308, 309=>309, 310=>310, 311=>311, 312=>312, 313=>313, 314=>314, 315=>315, 316=>316, 317=>317, 318=>318, 319=>319, 320=>320, 321=>321, 322=>322, 323=>323, 324=>324, 325=>325, 326=>326, 327=>327, 328=>328, 329=>329, 330=>330, 331=>331, 332=>332, 333=>333, 334=>334, 335=>335, 336=>336, 337=>337, 338=>338, 339=>339, 340=>340, 341=>341, 342=>342, 343=>343, 344=>344, 345=>345, 346=>346, 347=>347, 348=>348, 349=>349, 350=>350, 351=>351, 352=>352, 353=>353, 354=>354, 355=>355, 356=>356, 357=>357, 358=>358, 359=>359, 360=>360, 361=>361, 362=>362, 363=>363, 364=>364, 365=>365, 366=>366, 367=>367, 368=>368, 369=>369, 370=>370, 371=>371, 372=>372, 373=>373, 374=>374, 375=>375, 376=>376, 377=>377, 378=>378, 379=>379, 380=>380, 381=>381, 382=>382, 383=>383, 384=>384, 385=>385, 386=>386, 387=>387, 388=>388, 389=>389, 390=>390, 391=>391, 392=>392, 393=>393, 394=>394, 395=>395, 396=>396, 397=>397, 398=>398, 399=>399, 400=>400, 401=>401, 402=>402, 403=>403, 404=>404, 405=>405, 406=>406, 407=>407, 408=>408, 409=>409, 410=>410, 411=>411, 412=>412, 413=>413, 414=>414, 415=>415, 416=>416, 417=>417, 418=>418, 419=>419, 420=>420, 421=>421, 422=>422, 423=>423, 424=>424, 425=>425, 426=>426, 427=>427, 428=>428, 429=>429, 430=>430, 431=>431, 432=>432, 433=>433, 434=>434, 435=>435, 436=>436, 437=>437, 438=>438, 439=>439, 440=>440, 441=>441, 442=>442, 443=>443, 444=>444, 445=>445, 446=>446, 447=>447, 448=>448, 449=>449, 450=>450, 451=>451, 452=>452, 453=>453, 454=>454, 455=>455, 456=>456, 457=>457, 458=>458, 459=>459, 460=>460, 461=>461, 462=>462, 463=>463, 464=>464, 465=>465, 466=>466, 467=>467, 468=>468, 469=>469, 470=>470, 471=>471, 472=>472, 473=>473, 474=>474, 475=>475, 476=>476, 477=>477, 478=>478, 479=>479, 480=>480, 481=>481, 482=>482, 483=>483, 484=>484, 485=>485, 486=>486, 487=>487, 488=>488, 489=>489, 490=>490, 491=>491, 492=>492, 493=>493, 494=>494, 495=>495, 496=>496, 497=>497, 498=>498, 499=>499, 500=>500,}
-loop_count: 60000
diff --git a/benchmark/vm2_case.yml b/benchmark/vm2_case.yml
deleted file mode 100644
index 7716783c09..0000000000
--- a/benchmark/vm2_case.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-benchmark:
-  vm2_case: |
-    case :foo
-    when :bar
-      raise
-    when :baz
-      raise
-    when :boo
-      raise
-    when :foo
-      # noop
-    end
-loop_count: 6000000
diff --git a/benchmark/vm2_case_lit.yml b/benchmark/vm2_case_lit.yml
deleted file mode 100644
index c49b8dfe5e..0000000000
--- a/benchmark/vm2_case_lit.yml
+++ /dev/null
@@ -1,23 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_case_lit: |
-    i = 0
-    @ret = [ "foo", true, false, :sym, 6, nil, 0.1, 0xffffffffffffffff ]
-    def foo(i)
-      @ret[i % @ret.size]
-    end
-
-    while i<6_000_000
-      case foo(i)
-      when "foo" then :foo
-      when true then true
-      when false then false
-      when :sym then :sym
-      when 6 then :fix
-      when nil then nil
-      when 0.1 then :float
-      when 0xffffffffffffffff then :big
-      end
-      i += 1
-    end
-loop_count: 1
diff --git a/benchmark/vm2_defined_method.yml b/benchmark/vm2_defined_method.yml
deleted file mode 100644
index e1b0d55674..0000000000
--- a/benchmark/vm2_defined_method.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  class Object
-    define_method(:m){}
-  end
-benchmark:
-  vm2_defined_method: |
-    m; m; m; m; m; m; m; m;
-loop_count: 6000000
diff --git a/benchmark/vm2_dstr.yml b/benchmark/vm2_dstr.yml
deleted file mode 100644
index f8bd6e0133..0000000000
--- a/benchmark/vm2_dstr.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-prelude: |
-  x = y = 'z'
-benchmark:
-  vm2_dstr: |
-    str = "foo#{x}bar#{y}baz"
-loop_count: 6000000
diff --git a/benchmark/vm2_eval.yml b/benchmark/vm2_eval.yml
deleted file mode 100644
index d506a9c079..0000000000
--- a/benchmark/vm2_eval.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm2_eval: |
-    eval("1")
-loop_count: 6000000
diff --git a/benchmark/vm2_fiber_allocate.yml b/benchmark/vm2_fiber_allocate.yml
deleted file mode 100644
index f29705f694..0000000000
--- a/benchmark/vm2_fiber_allocate.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  # Disable GC to see raw throughput:
-  GC.disable
-benchmark:
-  vm2_fiber_allocate: |
-    fiber = Fiber.new{Fiber.yield}
-    fiber.resume
-loop_count: 100000
diff --git a/benchmark/vm2_fiber_count.yml b/benchmark/vm2_fiber_count.yml
deleted file mode 100644
index 3ecf6bdcb2..0000000000
--- a/benchmark/vm2_fiber_count.yml
+++ /dev/null
@@ -1,10 +0,0 @@
-# On Linux, you will need to increase the maximum number of memory maps:
-# sudo sysctl -w vm.max_map_count=200000
-prelude: |
-  fibers = []
-benchmark:
-  vm2_fiber_count: |
-    fiber = Fiber.new{Fiber.yield}
-    fibers << fiber
-    fiber.resume
-loop_count: 100000
diff --git a/benchmark/vm2_fiber_reuse.yml b/benchmark/vm2_fiber_reuse.yml
deleted file mode 100644
index 0170650638..0000000000
--- a/benchmark/vm2_fiber_reuse.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-prelude: |
-  GC.disable
-  fibers = []
-benchmark:
-  vm2_fiber_reuse: |
-    1024.times do
-      fiber = Fiber.new{Fiber.yield}
-      fibers << fiber
-      fiber.resume
-    end
-
-    fibers.clear
-    GC.start
-loop_count: 200
diff --git a/benchmark/vm2_fiber_reuse_gc.yml b/benchmark/vm2_fiber_reuse_gc.yml
deleted file mode 100644
index 8fb91a84eb..0000000000
--- a/benchmark/vm2_fiber_reuse_gc.yml
+++ /dev/null
@@ -1,12 +0,0 @@
-# https://bugs.ruby-lang.org/issues/16009
-prelude: |
-  fibers = []
-benchmark:
-  vm2_fiber_reuse_gc: |
-    2000.times do
-      fiber = Fiber.new{Fiber.yield}
-      fibers << fiber
-      fiber.resume
-    end
-    fibers.clear
-loop_count: 100
diff --git a/benchmark/vm2_fiber_switch.yml b/benchmark/vm2_fiber_switch.yml
deleted file mode 100644
index fbf7283c29..0000000000
--- a/benchmark/vm2_fiber_switch.yml
+++ /dev/null
@@ -1,9 +0,0 @@
-prelude: |
-  # based on benchmark for [ruby-core:65518] [Feature #10341] by Knut Franke
-  fib = Fiber.new do
-    loop { Fiber.yield }
-  end
-benchmark:
-  vm2_fiber_switch: |
-    fib.resume
-loop_count: 20000000
diff --git a/benchmark/vm2_freezestring.yml b/benchmark/vm2_freezestring.yml
deleted file mode 100644
index b78af91a20..0000000000
--- a/benchmark/vm2_freezestring.yml
+++ /dev/null
@@ -1,10 +0,0 @@
-prelude: |
-  class String
-    def freeze
-      -self
-    end
-  end
-benchmark:
-  vm2_freezestring: |
-    "tXnL1BP5T1WPXMjuFNLQtallEtRcay1t2lHtJSrlVsDgvunlbtfpr/DGdH0NGYE9".freeze
-loop_count: 6000000
diff --git a/benchmark/vm2_method.yml b/benchmark/vm2_method.yml
deleted file mode 100644
index cc7b9b28ff..0000000000
--- a/benchmark/vm2_method.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  def m
-    nil
-  end
-benchmark:
-  vm2_method: |
-    m; m; m; m; m; m; m; m;
-loop_count: 6000000
diff --git a/benchmark/vm2_method_missing.yml b/benchmark/vm2_method_missing.yml
deleted file mode 100644
index cbfb794b25..0000000000
--- a/benchmark/vm2_method_missing.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-prelude: |
-  class C
-    def method_missing mid
-    end
-  end
-
-  obj = C.new
-benchmark:
-  vm2_method_missing: |
-    obj.m; obj.m; obj.m; obj.m; obj.m; obj.m; obj.m; obj.m;
-loop_count: 6000000
diff --git a/benchmark/vm2_method_with_block.yml b/benchmark/vm2_method_with_block.yml
deleted file mode 100644
index 6e522adccc..0000000000
--- a/benchmark/vm2_method_with_block.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  def m
-    nil
-  end
-benchmark:
-  vm2_method_with_block: |
-    m{}; m{}; m{}; m{}; m{}; m{}; m{}; m{};
-loop_count: 6000000
diff --git a/benchmark/vm2_module_ann_const_set.yml b/benchmark/vm2_module_ann_const_set.yml
deleted file mode 100644
index b0becd9d3d..0000000000
--- a/benchmark/vm2_module_ann_const_set.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm2_module_ann_const_set: |
-    Module.new.const_set(:X, Module.new)
-loop_count: 6000000
diff --git a/benchmark/vm2_module_const_set.yml b/benchmark/vm2_module_const_set.yml
deleted file mode 100644
index 05a640069c..0000000000
--- a/benchmark/vm2_module_const_set.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  module M
-  end
-  $VERBOSE = nil
-benchmark:
-  vm2_module_const_set: |
-    M.const_set(:X, Module.new)
-loop_count: 6000000
diff --git a/benchmark/vm2_mutex.yml b/benchmark/vm2_mutex.yml
deleted file mode 100644
index c40a90444a..0000000000
--- a/benchmark/vm2_mutex.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  require 'thread'
-
-  m = Thread::Mutex.new
-benchmark:
-  vm2_mutex: |
-    m.synchronize{}
-loop_count: 6000000
diff --git a/benchmark/vm2_newlambda.yml b/benchmark/vm2_newlambda.yml
deleted file mode 100644
index 93133f9f30..0000000000
--- a/benchmark/vm2_newlambda.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm2_newlambda: |
-    lambda {}
-loop_count: 6000000
diff --git a/benchmark/vm2_poly_method.yml b/benchmark/vm2_poly_method.yml
deleted file mode 100644
index 0104bdfb66..0000000000
--- a/benchmark/vm2_poly_method.yml
+++ /dev/null
@@ -1,24 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_poly_method: |
-    class C1
-      def m
-        1
-      end
-    end
-    class C2
-      def m
-        2
-      end
-    end
-
-    o1 = C1.new
-    o2 = C2.new
-
-    i = 0
-    while i<6_000_000
-      o = (i % 2 == 0) ? o1 : o2
-      o.m; o.m; o.m; o.m; o.m; o.m; o.m; o.m
-      i += 1
-    end
-loop_count: 1
diff --git a/benchmark/vm2_poly_method_ov.yml b/benchmark/vm2_poly_method_ov.yml
deleted file mode 100644
index 3748073ba2..0000000000
--- a/benchmark/vm2_poly_method_ov.yml
+++ /dev/null
@@ -1,24 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_poly_method_ov: |
-    class C1
-      def m
-        1
-      end
-    end
-    class C2
-      def m
-        2
-      end
-    end
-
-    o1 = C1.new
-    o2 = C2.new
-
-    i = 0
-    while i<6_000_000
-      o = (i % 2 == 0) ? o1 : o2
-    #  o.m; o.m; o.m; o.m; o.m; o.m; o.m; o.m
-      i += 1
-    end
-loop_count: 1
diff --git a/benchmark/vm2_poly_same_method.yml b/benchmark/vm2_poly_same_method.yml
deleted file mode 100644
index 867c433cf8..0000000000
--- a/benchmark/vm2_poly_same_method.yml
+++ /dev/null
@@ -1,25 +0,0 @@
-prelude: |
-  module AR; end
-  class AR::Base
-    def create_or_update
-      nil
-    end
-    def save
-      create_or_update
-    end
-  end
-  class Foo < AR::Base; end
-  class Bar < AR::Base; end
-  o1 = Foo.new
-  o2 = Bar.new
-benchmark:
-  vm2_poly_same_method: |
-    o1.save; o2.save;
-    o1.save; o2.save;
-    o1.save; o2.save;
-    o1.save; o2.save;
-    o1.save; o2.save;
-    o1.save; o2.save;
-    o1.save; o2.save;
-    o1.save; o2.save;
-loop_count: 6000000
diff --git a/benchmark/vm2_poly_singleton.yml b/benchmark/vm2_poly_singleton.yml
deleted file mode 100644
index e58d7bfb37..0000000000
--- a/benchmark/vm2_poly_singleton.yml
+++ /dev/null
@@ -1,18 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_poly_singleton: |
-    class C1
-      def m; 1; end
-    end
-
-    o1 = C1.new
-    o2 = C1.new
-    o2.singleton_class
-
-    i = 0
-    while i<6_000_000 # benchmark loop 2
-      o = (i % 2 == 0) ? o1 : o2
-      o.m; o.m; o.m; o.m; o.m; o.m; o.m; o.m
-      i += 1
-    end
-loop_count: 1
diff --git a/benchmark/vm2_proc.yml b/benchmark/vm2_proc.yml
deleted file mode 100644
index 5c36e936d9..0000000000
--- a/benchmark/vm2_proc.yml
+++ /dev/null
@@ -1,12 +0,0 @@
-prelude: |
-  def m &b
-    b
-  end
-
-  pr = m{
-    a = 1
-  }
-benchmark:
-  vm2_proc: |
-    pr.call
-loop_count: 6000000
diff --git a/benchmark/vm2_raise1.yml b/benchmark/vm2_raise1.yml
deleted file mode 100644
index f6eb308968..0000000000
--- a/benchmark/vm2_raise1.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-prelude: |
-  def rec n
-    if n > 0
-      rec n-1
-    else
-      raise
-    end
-  end
-benchmark:
-  vm2_raise1: |
-    begin
-      rec 1
-    rescue
-      # ignore
-    end
-loop_count: 6000000
diff --git a/benchmark/vm2_raise2.yml b/benchmark/vm2_raise2.yml
deleted file mode 100644
index 7d51b1b314..0000000000
--- a/benchmark/vm2_raise2.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-prelude: |
-  def rec n
-    if n > 0
-      rec n-1
-    else
-      raise
-    end
-  end
-benchmark:
-  vm2_raise2: |
-    begin
-      rec 10
-    rescue
-      # ignore
-    end
-loop_count: 6000000
diff --git a/benchmark/vm2_regexp.yml b/benchmark/vm2_regexp.yml
deleted file mode 100644
index e53341f43b..0000000000
--- a/benchmark/vm2_regexp.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-prelude: |
-  str = 'xxxhogexxx'
-benchmark:
-  vm2_regexp: |
-    /hoge/ =~ str
-  vm2_regexp_invert: |
-    str =~ /hoge/
-loop_count: 6000000
diff --git a/benchmark/vm2_send.yml b/benchmark/vm2_send.yml
deleted file mode 100644
index 44a12a27d9..0000000000
--- a/benchmark/vm2_send.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-prelude: |
-  class C
-    def m
-    end
-  end
-
-  o = C.new
-benchmark:
-  vm2_send: |
-    o.__send__ :m
-loop_count: 6000000
diff --git a/benchmark/vm2_string_literal.yml b/benchmark/vm2_string_literal.yml
deleted file mode 100644
index 54b0aec1fe..0000000000
--- a/benchmark/vm2_string_literal.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-benchmark:
-  vm2_string_literal: |
-    x = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_big_aref_hi.yml b/benchmark/vm2_struct_big_aref_hi.yml
deleted file mode 100644
index eed1846d28..0000000000
--- a/benchmark/vm2_struct_big_aref_hi.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
-  x = s.new
-benchmark:
-  vm2_struct_big_aref_hi: |
-    x.z # x[25]
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_big_aref_lo.yml b/benchmark/vm2_struct_big_aref_lo.yml
deleted file mode 100644
index 0915435b76..0000000000
--- a/benchmark/vm2_struct_big_aref_lo.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
-  x = s.new
-benchmark:
-  vm2_struct_big_aref_lo: |
-    x.k # x[10]
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_big_aset.yml b/benchmark/vm2_struct_big_aset.yml
deleted file mode 100644
index 6af50103d3..0000000000
--- a/benchmark/vm2_struct_big_aset.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_struct_big_aset: |
-    s = Struct.new(*('a'..'z').map { |x| x.to_sym })
-    x = s.new
-    i = 0
-    while i<6_000_000
-      i += 1
-      x.k = i # x[10] = i
-    end
-loop_count: 1
diff --git a/benchmark/vm2_struct_big_href_hi.yml b/benchmark/vm2_struct_big_href_hi.yml
deleted file mode 100644
index 60aa7fddf3..0000000000
--- a/benchmark/vm2_struct_big_href_hi.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
-  x = s.new
-benchmark:
-  vm2_struct_big_href_hi: |
-    x[:z]
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_big_href_lo.yml b/benchmark/vm2_struct_big_href_lo.yml
deleted file mode 100644
index c55c0bd16c..0000000000
--- a/benchmark/vm2_struct_big_href_lo.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
-  x = s.new
-benchmark:
-  vm2_struct_big_href_lo: |
-    x[:k]
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_big_hset.yml b/benchmark/vm2_struct_big_hset.yml
deleted file mode 100644
index d199c5bd47..0000000000
--- a/benchmark/vm2_struct_big_hset.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_struct_big_hset: |
-    s = Struct.new(*('a'..'z').map { |x| x.to_sym })
-    x = s.new
-    i = 0
-    while i<6_000_000
-      i += 1
-      x[:k] = i
-    end
-loop_count: 1
diff --git a/benchmark/vm2_struct_small_aref.yml b/benchmark/vm2_struct_small_aref.yml
deleted file mode 100644
index 83381bed3a..0000000000
--- a/benchmark/vm2_struct_small_aref.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(:a, :b, :c)
-  x = s.new
-benchmark:
-  vm2_struct_small_aref: |
-    x.a
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_small_aset.yml b/benchmark/vm2_struct_small_aset.yml
deleted file mode 100644
index 3e84a61dd0..0000000000
--- a/benchmark/vm2_struct_small_aset.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-# loop_count is not utilized since `i` is involved in the script
-benchmark:
-  vm2_struct_small_aset: |
-    s = Struct.new(:a, :b, :c)
-    x = s.new
-    i = 0
-    while i<6_000_000
-      i += 1
-      x.a = i
-    end
-loop_count: 1
diff --git a/benchmark/vm2_struct_small_href.yml b/benchmark/vm2_struct_small_href.yml
deleted file mode 100644
index b744f070d1..0000000000
--- a/benchmark/vm2_struct_small_href.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(:a, :b, :c)
-  x = s.new
-benchmark:
-  vm2_struct_small_href: |
-    x[:a]
-loop_count: 6000000
diff --git a/benchmark/vm2_struct_small_hset.yml b/benchmark/vm2_struct_small_hset.yml
deleted file mode 100644
index d43845d6e0..0000000000
--- a/benchmark/vm2_struct_small_hset.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  s = Struct.new(:a, :b, :c)
-  x = s.new
-benchmark:
-  vm2_struct_small_hset: |
-    x[:a] = 1
-loop_count: 6000000
diff --git a/benchmark/vm2_super.yml b/benchmark/vm2_super.yml
deleted file mode 100644
index 674743762a..0000000000
--- a/benchmark/vm2_super.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-prelude: |
-  class C
-    def m
-      1
-    end
-  end
-
-  class CC < C
-    def m
-      super()
-    end
-  end
-
-  obj = CC.new
-benchmark:
-  vm2_super: obj.m
-loop_count: 6000000
diff --git a/benchmark/vm2_unif1.yml b/benchmark/vm2_unif1.yml
deleted file mode 100644
index caef13279f..0000000000
--- a/benchmark/vm2_unif1.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-prelude: |
-  def m a, b
-  end
-benchmark:
-  vm2_unif1: |
-    m 100, 200
-loop_count: 6000000
diff --git a/benchmark/vm2_zsuper.yml b/benchmark/vm2_zsuper.yml
deleted file mode 100644
index f760cfd48e..0000000000
--- a/benchmark/vm2_zsuper.yml
+++ /dev/null
@@ -1,18 +0,0 @@
-prelude: |
-  class C
-    def m a
-      1
-    end
-  end
-
-  class CC < C
-    def m a
-      super
-    end
-  end
-
-  obj = CC.new
-benchmark:
-  vm2_zsuper: |
-    obj.m 10
-loop_count: 6000000
diff --git a/benchmark/vm_array.yml b/benchmark/vm_array.yml
new file mode 100644
index 0000000000..2a177237ef
--- /dev/null
+++ b/benchmark/vm_array.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_array: |
+    a = [1,2,3,4,5,6,7,8,9,10]
+loop_count: 6000000
diff --git a/benchmark/vm_attr_ivar.yml b/benchmark/vm_attr_ivar.yml
new file mode 100644
index 0000000000..75b803478e
--- /dev/null
+++ b/benchmark/vm_attr_ivar.yml
@@ -0,0 +1,14 @@
+prelude: |
+  class C
+    attr_reader :a, :b
+    def initialize
+      @a = nil
+      @b = nil
+    end
+  end
+  obj = C.new
+benchmark:
+  vm_attr_ivar: |
+    j = obj.a
+    k = obj.b
+loop_count: 30000000
diff --git a/benchmark/vm_attr_ivar_set.yml b/benchmark/vm_attr_ivar_set.yml
new file mode 100644
index 0000000000..a0d379b18a
--- /dev/null
+++ b/benchmark/vm_attr_ivar_set.yml
@@ -0,0 +1,14 @@
+prelude: |
+  class C
+    attr_accessor :a, :b
+    def initialize
+      @a = nil
+      @b = nil
+    end
+  end
+  obj = C.new
+benchmark:
+  vm_attr_ivar_set: |
+    obj.a = 1
+    obj.b = 2
+loop_count: 30000000
diff --git a/benchmark/vm3_backtrace.rb b/benchmark/vm_backtrace.rb
index 0fbf73e1ca..0fbf73e1ca 100644
--- a/benchmark/vm3_backtrace.rb
+++ b/benchmark/vm_backtrace.rb
diff --git a/benchmark/vm_bigarray.yml b/benchmark/vm_bigarray.yml
new file mode 100644
index 0000000000..8b2d3f3443
--- /dev/null
+++ b/benchmark/vm_bigarray.yml
@@ -0,0 +1,105 @@
+benchmark:
+  vm_bigarray: |
+    a = [
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+      1,2,3,4,5,6,7,8,9,10,
+    ]
+loop_count: 6000000
diff --git a/benchmark/vm_bighash.yml b/benchmark/vm_bighash.yml
new file mode 100644
index 0000000000..4dacfde793
--- /dev/null
+++ b/benchmark/vm_bighash.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_bighash: |
+    a = {0=>0, 1=>1, 2=>2, 3=>3, 4=>4, 5=>5, 6=>6, 7=>7, 8=>8, 9=>9, 10=>10, 11=>11, 12=>12, 13=>13, 14=>14, 15=>15, 16=>16, 17=>17, 18=>18, 19=>19, 20=>20, 21=>21, 22=>22, 23=>23, 24=>24, 25=>25, 26=>26, 27=>27, 28=>28, 29=>29, 30=>30, 31=>31, 32=>32, 33=>33, 34=>34, 35=>35, 36=>36, 37=>37, 38=>38, 39=>39, 40=>40, 41=>41, 42=>42, 43=>43, 44=>44, 45=>45, 46=>46, 47=>47, 48=>48, 49=>49, 50=>50, 51=>51, 52=>52, 53=>53, 54=>54, 55=>55, 56=>56, 57=>57, 58=>58, 59=>59, 60=>60, 61=>61, 62=>62, 63=>63, 64=>64, 65=>65, 66=>66, 67=>67, 68=>68, 69=>69, 70=>70, 71=>71, 72=>72, 73=>73, 74=>74, 75=>75, 76=>76, 77=>77, 78=>78, 79=>79, 80=>80, 81=>81, 82=>82, 83=>83, 84=>84, 85=>85, 86=>86, 87=>87, 88=>88, 89=>89, 90=>90, 91=>91, 92=>92, 93=>93, 94=>94, 95=>95, 96=>96, 97=>97, 98=>98, 99=>99, 100=>100, 101=>101, 102=>102, 103=>103, 104=>104, 105=>105, 106=>106, 107=>107, 108=>108, 109=>109, 110=>110, 111=>111, 112=>112, 113=>113, 114=>114, 115=>115, 116=>116, 117=>117, 118=>118, 119=>119, 120=>120, 121=>121, 122=>122, 123=>123, 124=>124, 125=>125, 126=>126, 127=>127, 128=>128, 129=>129, 130=>130, 131=>131, 132=>132, 133=>133, 134=>134, 135=>135, 136=>136, 137=>137, 138=>138, 139=>139, 140=>140, 141=>141, 142=>142, 143=>143, 144=>144, 145=>145, 146=>146, 147=>147, 148=>148, 149=>149, 150=>150, 151=>151, 152=>152, 153=>153, 154=>154, 155=>155, 156=>156, 157=>157, 158=>158, 159=>159, 160=>160, 161=>161, 162=>162, 163=>163, 164=>164, 165=>165, 166=>166, 167=>167, 168=>168, 169=>169, 170=>170, 171=>171, 172=>172, 173=>173, 174=>174, 175=>175, 176=>176, 177=>177, 178=>178, 179=>179, 180=>180, 181=>181, 182=>182, 183=>183, 184=>184, 185=>185, 186=>186, 187=>187, 188=>188, 189=>189, 190=>190, 191=>191, 192=>192, 193=>193, 194=>194, 195=>195, 196=>196, 197=>197, 198=>198, 199=>199, 200=>200, 201=>201, 202=>202, 203=>203, 204=>204, 205=>205, 206=>206, 207=>207, 208=>208, 209=>209, 210=>210, 211=>211, 212=>212, 213=>213, 214=>214, 215=>215, 216=>216, 217=>217, 218=>218, 219=>219, 220=>220, 221=>221, 222=>222, 223=>223, 224=>224, 225=>225, 226=>226, 227=>227, 228=>228, 229=>229, 230=>230, 231=>231, 232=>232, 233=>233, 234=>234, 235=>235, 236=>236, 237=>237, 238=>238, 239=>239, 240=>240, 241=>241, 242=>242, 243=>243, 244=>244, 245=>245, 246=>246, 247=>247, 248=>248, 249=>249, 250=>250, 251=>251, 252=>252, 253=>253, 254=>254, 255=>255, 256=>256, 257=>257, 258=>258, 259=>259, 260=>260, 261=>261, 262=>262, 263=>263, 264=>264, 265=>265, 266=>266, 267=>267, 268=>268, 269=>269, 270=>270, 271=>271, 272=>272, 273=>273, 274=>274, 275=>275, 276=>276, 277=>277, 278=>278, 279=>279, 280=>280, 281=>281, 282=>282, 283=>283, 284=>284, 285=>285, 286=>286, 287=>287, 288=>288, 289=>289, 290=>290, 291=>291, 292=>292, 293=>293, 294=>294, 295=>295, 296=>296, 297=>297, 298=>298, 299=>299, 300=>300, 301=>301, 302=>302, 303=>303, 304=>304, 305=>305, 306=>306, 307=>307, 308=>308, 309=>309, 310=>310, 311=>311, 312=>312, 313=>313, 314=>314, 315=>315, 316=>316, 317=>317, 318=>318, 319=>319, 320=>320, 321=>321, 322=>322, 323=>323, 324=>324, 325=>325, 326=>326, 327=>327, 328=>328, 329=>329, 330=>330, 331=>331, 332=>332, 333=>333, 334=>334, 335=>335, 336=>336, 337=>337, 338=>338, 339=>339, 340=>340, 341=>341, 342=>342, 343=>343, 344=>344, 345=>345, 346=>346, 347=>347, 348=>348, 349=>349, 350=>350, 351=>351, 352=>352, 353=>353, 354=>354, 355=>355, 356=>356, 357=>357, 358=>358, 359=>359, 360=>360, 361=>361, 362=>362, 363=>363, 364=>364, 365=>365, 366=>366, 367=>367, 368=>368, 369=>369, 370=>370, 371=>371, 372=>372, 373=>373, 374=>374, 375=>375, 376=>376, 377=>377, 378=>378, 379=>379, 380=>380, 381=>381, 382=>382, 383=>383, 384=>384, 385=>385, 386=>386, 387=>387, 388=>388, 389=>389, 390=>390, 391=>391, 392=>392, 393=>393, 394=>394, 395=>395, 396=>396, 397=>397, 398=>398, 399=>399, 400=>400, 401=>401, 402=>402, 403=>403, 404=>404, 405=>405, 406=>406, 407=>407, 408=>408, 409=>409, 410=>410, 411=>411, 412=>412, 413=>413, 414=>414, 415=>415, 416=>416, 417=>417, 418=>418, 419=>419, 420=>420, 421=>421, 422=>422, 423=>423, 424=>424, 425=>425, 426=>426, 427=>427, 428=>428, 429=>429, 430=>430, 431=>431, 432=>432, 433=>433, 434=>434, 435=>435, 436=>436, 437=>437, 438=>438, 439=>439, 440=>440, 441=>441, 442=>442, 443=>443, 444=>444, 445=>445, 446=>446, 447=>447, 448=>448, 449=>449, 450=>450, 451=>451, 452=>452, 453=>453, 454=>454, 455=>455, 456=>456, 457=>457, 458=>458, 459=>459, 460=>460, 461=>461, 462=>462, 463=>463, 464=>464, 465=>465, 466=>466, 467=>467, 468=>468, 469=>469, 470=>470, 471=>471, 472=>472, 473=>473, 474=>474, 475=>475, 476=>476, 477=>477, 478=>478, 479=>479, 480=>480, 481=>481, 482=>482, 483=>483, 484=>484, 485=>485, 486=>486, 487=>487, 488=>488, 489=>489, 490=>490, 491=>491, 492=>492, 493=>493, 494=>494, 495=>495, 496=>496, 497=>497, 498=>498, 499=>499, 500=>500,}
+loop_count: 60000
diff --git a/benchmark/vm_block.yml b/benchmark/vm_block.yml
new file mode 100644
index 0000000000..68b3e40bf5
--- /dev/null
+++ b/benchmark/vm_block.yml
@@ -0,0 +1,9 @@
+prelude: |
+  def m
+    yield
+  end
+benchmark:
+  vm_block: |
+    m{
+    }
+loop_count: 30000000
diff --git a/benchmark/vm_block_handler.yml b/benchmark/vm_block_handler.yml
new file mode 100644
index 0000000000..461d7953ad
--- /dev/null
+++ b/benchmark/vm_block_handler.yml
@@ -0,0 +1,27 @@
+# :FIXME: is there a way to benchmark block_handler_type_ifunc?
+
+prelude: |
+  p = proc{_1}
+  o = Object.new
+  def o.each
+    i = 0
+    while i < 3_000_000 do
+      yield i
+      i += 1
+    end
+  end
+
+benchmark:
+  - name: block_handler_type_iseq
+    script: |
+      o.each{_1}
+
+  - name: block_handler_type_symbol
+    script: |
+      o.each(&:itself)
+
+  - name: block_handler_type_proc
+    script: |
+      o.each(&p)
+
+loop_count: 1
diff --git a/benchmark/vm_blockparam.yml b/benchmark/vm_blockparam.yml
new file mode 100644
index 0000000000..5e5a0170a2
--- /dev/null
+++ b/benchmark/vm_blockparam.yml
@@ -0,0 +1,7 @@
+prelude: |
+  def m &b
+  end
+benchmark:
+  vm_blockparam: |
+    m{}
+loop_count: 30000000
diff --git a/benchmark/vm_blockparam_call.yml b/benchmark/vm_blockparam_call.yml
new file mode 100644
index 0000000000..a7d8d366ea
--- /dev/null
+++ b/benchmark/vm_blockparam_call.yml
@@ -0,0 +1,8 @@
+prelude: |
+  def m &b
+    b.call
+  end
+benchmark:
+  vm_blockparam_call: |
+    m{}
+loop_count: 30000000
diff --git a/benchmark/vm_blockparam_pass.yml b/benchmark/vm_blockparam_pass.yml
new file mode 100644
index 0000000000..841f5e7a63
--- /dev/null
+++ b/benchmark/vm_blockparam_pass.yml
@@ -0,0 +1,12 @@
+prelude: |
+  def bp_yield
+    yield
+  end
+
+  def bp_pass &b
+    bp_yield &b
+  end
+benchmark:
+  vm_blockparam_pass: |
+    bp_pass{}
+loop_count: 30000000
diff --git a/benchmark/vm_blockparam_yield.yml b/benchmark/vm_blockparam_yield.yml
new file mode 100644
index 0000000000..8ea9b46ed2
--- /dev/null
+++ b/benchmark/vm_blockparam_yield.yml
@@ -0,0 +1,8 @@
+prelude: |
+  def bp_yield &b
+    yield
+  end
+benchmark:
+  vm_blockparam_yield: |
+    bp_yield{}
+loop_count: 30000000
diff --git a/benchmark/vm_call_bmethod.yml b/benchmark/vm_call_bmethod.yml
new file mode 100644
index 0000000000..40136e5aa4
--- /dev/null
+++ b/benchmark/vm_call_bmethod.yml
@@ -0,0 +1,37 @@
+prelude: |
+  define_method(:a0){}
+  define_method(:a1){|a| a}
+  define_method(:s){|*a| a}
+  define_method(:b){|kw: 1| kw}
+
+  t0 = 0.times.to_a
+  t1 = 1.times.to_a
+  t10 = 10.times.to_a
+  t100 = 100.times.to_a
+  kw = {kw: 2}
+benchmark:
+  bmethod_simple_0: |
+    a0
+  bmethod_simple_1: |
+    a1(1)
+  bmethod_simple_0_splat: |
+    a0(*t0)
+  bmethod_simple_1_splat: |
+    a1(*t1)
+  bmethod_no_splat: |
+    s
+  bmethod_0_splat: |
+    s(*t0)
+  bmethod_1_splat: |
+    s(*t1)
+  bmethod_10_splat: |
+    s(*t10)
+  bmethod_100_splat: |
+    s(*t100)
+  bmethod_kw: |
+    b(kw: 1)
+  bmethod_no_kw: |
+    b
+  bmethod_kw_splat: |
+    b(**kw)
+loop_count: 6000000
diff --git a/benchmark/vm_call_kw_and_kw_splat.yml b/benchmark/vm_call_kw_and_kw_splat.yml
new file mode 100644
index 0000000000..aa6e549e0c
--- /dev/null
+++ b/benchmark/vm_call_kw_and_kw_splat.yml
@@ -0,0 +1,25 @@
+prelude: |
+  h1, h10, h100, h1000 = [1, 10, 100, 1000].map do |n|
+    h = {kw: 1}
+    n.times{|i| h[i.to_s.to_sym] = i}
+    h
+  end
+  eh = {}
+  def kw(kw: nil, **kws) end
+benchmark:
+  1: |
+    kw(**h1)
+  1_mutable: |
+    kw(**eh, **h1)
+  10: |
+    kw(**h10)
+  10_mutable: |
+    kw(**eh, **h10)
+  100: |
+    kw(**h100)
+  100_mutable: |
+    kw(**eh, **h100)
+  1000: |
+    kw(**h1000)
+  1000_mutable: |
+    kw(**eh, **h1000)
diff --git a/benchmark/vm_call_method_missing.yml b/benchmark/vm_call_method_missing.yml
new file mode 100644
index 0000000000..f890796f11
--- /dev/null
+++ b/benchmark/vm_call_method_missing.yml
@@ -0,0 +1,62 @@
+prelude: |
+  class A0
+    def method_missing(m); m end
+  end
+  class A1
+    def method_missing(m, a) a; end
+  end
+  class S
+    def method_missing(m, *a) a; end
+  end
+  class B
+    def method_missing(m, kw: 1) kw end
+  end
+  class SB
+    def method_missing(m, *a, kw: 1) kw end
+  end
+
+  t0 = 0.times.to_a
+  t1 = 1.times.to_a
+  t10 = 10.times.to_a
+  t200 = 200.times.to_a
+  kw = {kw: 2}
+
+  a0 = A0.new
+  a1 = A1.new
+  s = S.new
+  b = B.new
+  sb = SB.new
+benchmark:
+  method_missing_simple_0: |
+    a0.()
+  method_missing_simple_1: |
+    a1.x(1)
+  method_missing_simple_0_splat: |
+    a0.(*t0)
+  method_missing_simple_1_splat: |
+    a1.(*t1)
+  method_missing_no_splat: |
+    s.()
+  method_missing_0_splat: |
+    s.(*t0)
+  method_missing_1_splat: |
+    s.(*t1)
+  method_missing_10_splat: |
+    s.(*t10)
+  method_missing_200_splat: |
+    s.(*t200)
+  method_missing_kw: |
+    b.(kw: 1)
+  method_missing_no_kw: |
+    b.()
+  method_missing_kw_splat: |
+    b.(**kw)
+  method_missing_0_splat_kw: |
+    sb.(*t0, **kw)
+  method_missing_1_splat_kw: |
+    sb.(*t1, **kw)
+  method_missing_10_splat_kw: |
+    sb.(*t10, **kw)
+  method_missing_200_splat_kw: |
+    sb.(*t200, **kw)
+loop_count: 1000000
diff --git a/benchmark/vm_call_send_iseq.yml b/benchmark/vm_call_send_iseq.yml
new file mode 100644
index 0000000000..60ff23c475
--- /dev/null
+++ b/benchmark/vm_call_send_iseq.yml
@@ -0,0 +1,77 @@
+prelude: |
+  def a0; end
+  def a1(a) a; end
+  def s(*a) a; end
+  def b(kw: 1) kw end
+  def sb(*a, kw: 1) kw end
+
+  t0 = 0.times.to_a
+  t1 = 1.times.to_a
+  t10 = 10.times.to_a
+  t200 = 200.times.to_a
+
+  a0_t0 = [:a0, *t0]
+  a1_t1 = [:a1, *t1]
+  s_t0 = [:s, *t0]
+  s_t1 = [:s, *t1]
+  s_t10 = [:s, *t10]
+  s_t200 = [:s, *t200]
+  sb_t0 = [:sb, *t0]
+  sb_t1 = [:sb, *t1]
+  sb_t10 = [:sb, *t10]
+  sb_t200 = [:sb, *t200]
+  kw = {kw: 2}
+benchmark:
+  send_simple_0: |
+    send(:a0)
+  send_simple_1: |
+    send(:a1, 1)
+  send_simple_0_splat: |
+    send(:a0, *t0)
+  send_simple_1_splat: |
+    send(:a1, *t1)
+  send_simple_0_splat_comb: |
+    send(*a0_t0)
+  send_simple_1_splat_comb: |
+    send(*a1_t1)
+  send_no_splat: |
+    send(:s)
+  send_0_splat: |
+    send(:s, *t0)
+  send_1_splat: |
+    send(:s, *t1)
+  send_10_splat: |
+    send(:s, *t10)
+  send_200_splat: |
+    send(:s, *t200)
+  send_0_splat_comb: |
+    send(*s_t0)
+  send_1_splat_comb: |
+    send(*s_t1)
+  send_10_splat_comb: |
+    send(*s_t10)
+  send_200_splat_comb: |
+    send(*s_t200)
+  send_kw: |
+    send(:b, kw: 1)
+  send_no_kw: |
+    send(:b)
+  send_kw_splat: |
+    send(:b, **kw)
+  send_0_splat_kw: |
+    send(:sb, *t0, **kw)
+  send_1_splat_kw: |
+    send(:sb, *t1, **kw)
+  send_10_splat_kw: |
+    send(:sb, *t10, **kw)
+  send_200_splat_kw: |
+    send(:sb, *t200, **kw)
+  send_0_splat_comb_kw: |
+    send(*sb_t0, **kw)
+  send_1_splat_comb_kw: |
+    send(*sb_t1, **kw)
+  send_10_splat_comb_kw: |
+    send(*sb_t10, **kw)
+  send_200_splat_comb_kw: |
+    send(*sb_t200, **kw)
+loop_count: 3000000
diff --git a/benchmark/vm_call_symproc.yml b/benchmark/vm_call_symproc.yml
new file mode 100644
index 0000000000..16e0ac579e
--- /dev/null
+++ b/benchmark/vm_call_symproc.yml
@@ -0,0 +1,83 @@
+prelude: |
+  def self.a0; end
+  def self.a1(a) a; end
+  def self.s(*a) a; end
+  def self.b(kw: 1) kw end
+  def self.sb(*a, kw: 1) kw end
+
+  t0 = 0.times.to_a
+  t1 = 1.times.to_a
+  t10 = 10.times.to_a
+  t200 = 200.times.to_a
+
+  a0_t0 = [self, *t0]
+  a1_t1 = [self, *t1]
+  s_t0 = [self, *t0]
+  s_t1 = [self, *t1]
+  s_t10 = [self, *t10]
+  s_t200 = [self, *t200]
+  sb_t0 = [self, *t0]
+  sb_t1 = [self, *t1]
+  sb_t10 = [self, *t10]
+  sb_t200 = [self, *t200]
+  kw = {kw: 2}
+
+  a0 = :a0.to_proc
+  a1 = :a1.to_proc
+  s = :s.to_proc
+  b = :b.to_proc
+  sb = :sb.to_proc
+benchmark:
+  symproc_simple_0: |
+    a0.(self)
+  symproc_simple_1: |
+    a1.(self, 1)
+  symproc_simple_0_splat: |
+    a0.(self, *t0)
+  symproc_simple_1_splat: |
+    a1.(self, *t1)
+  symproc_simple_0_splat_comb: |
+    a0.(*a0_t0)
+  symproc_simple_1_splat_comb: |
+    a1.(*a1_t1)
+  symproc_no_splat: |
+    s.(self)
+  symproc_0_splat: |
+    s.(self, *t0)
+  symproc_1_splat: |
+    s.(self, *t1)
+  symproc_10_splat: |
+    s.(self, *t10)
+  symproc_200_splat: |
+    s.(self, *t200)
+  symproc_0_splat_comb: |
+    s.(*s_t0)
+  symproc_1_splat_comb: |
+    s.(*s_t1)
+  symproc_10_splat_comb: |
+    s.(*s_t10)
+  symproc_200_splat_comb: |
+    s.(*s_t200)
+  symproc_kw: |
+    b.(self, kw: 1)
+  symproc_no_kw: |
+    b.(self)
+  symproc_kw_splat: |
+    b.(self, **kw)
+  symproc_0_splat_kw: |
+    sb.(self, *t0, **kw)
+  symproc_1_splat_kw: |
+    sb.(self, *t1, **kw)
+  symproc_10_splat_kw: |
+    sb.(self, *t10, **kw)
+  symproc_200_splat_kw: |
+    sb.(self, *t200, **kw)
+  symproc_0_splat_comb_kw: |
+    sb.(*sb_t0, **kw)
+  symproc_1_splat_comb_kw: |
+    sb.(*sb_t1, **kw)
+  symproc_10_splat_comb_kw: |
+    sb.(*sb_t10, **kw)
+  symproc_200_splat_comb_kw: |
+    sb.(*sb_t200, **kw)
+loop_count: 1000000
diff --git a/benchmark/vm_case.yml b/benchmark/vm_case.yml
new file mode 100644
index 0000000000..b26a491a15
--- /dev/null
+++ b/benchmark/vm_case.yml
@@ -0,0 +1,13 @@
+benchmark:
+  vm_case: |
+    case :foo
+    when :bar
+      raise
+    when :baz
+      raise
+    when :boo
+      raise
+    when :foo
+      # noop
+    end
+loop_count: 6000000
diff --git a/benchmark/vm_case_classes.yml b/benchmark/vm_case_classes.yml
new file mode 100644
index 0000000000..cacc4f0464
--- /dev/null
+++ b/benchmark/vm_case_classes.yml
@@ -0,0 +1,9 @@
+benchmark:
+  vm_case_classes: |
+    case :foo
+    when Hash
+      raise
+    when Array
+      raise
+    end
+loop_count: 6000000
diff --git a/benchmark/vm_case_lit.yml b/benchmark/vm_case_lit.yml
new file mode 100644
index 0000000000..9f91801544
--- /dev/null
+++ b/benchmark/vm_case_lit.yml
@@ -0,0 +1,23 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_case_lit: |
+    i = 0
+    @ret = [ "foo", true, false, :sym, 6, nil, 0.1, 0xffffffffffffffff ]
+    def foo(i)
+      @ret[i % @ret.size]
+    end
+
+    while i<6_000_000
+      case foo(i)
+      when "foo" then :foo
+      when true then true
+      when false then false
+      when :sym then :sym
+      when 6 then :fix
+      when nil then nil
+      when 0.1 then :float
+      when 0xffffffffffffffff then :big
+      end
+      i += 1
+    end
+loop_count: 1
diff --git a/benchmark/vm3_clearmethodcache.rb b/benchmark/vm_clearmethodcache.rb
index 9661323cd2..9661323cd2 100644
--- a/benchmark/vm3_clearmethodcache.rb
+++ b/benchmark/vm_clearmethodcache.rb
diff --git a/benchmark/vm_const.yml b/benchmark/vm_const.yml
new file mode 100644
index 0000000000..8939ca0cd3
--- /dev/null
+++ b/benchmark/vm_const.yml
@@ -0,0 +1,13 @@
+prelude: |
+  Const = 1
+  A = B = C = D = E = F = G = H = I = J = K = L = M = N = O = P = Q = R = S = T = U = V = W = X = Y = Z = 1
+  def foo
+    A; B; C; D; E; F; G; H; I; J; K; L; M; N; O; P; Q; R; S; T; U; V; W; X; Y; Z
+  end
+benchmark:
+  vm_const: |
+    j = Const
+    k = Const
+  vm_const_many: |
+    foo
+loop_count: 30000000
diff --git a/benchmark/vm_cvar.yml b/benchmark/vm_cvar.yml
new file mode 100644
index 0000000000..1d0e161829
--- /dev/null
+++ b/benchmark/vm_cvar.yml
@@ -0,0 +1,20 @@
+prelude: |
+  class A
+    @@foo = 1
+
+    def self.foo
+      @@foo
+    end
+
+    ("A".."Z").each do |module_name|
+      eval <<-EOM
+        module #{module_name}
+        end
+
+        include #{module_name}
+      EOM
+    end
+  end
+benchmark:
+  vm_cvar: A.foo
+loop_count: 600000
diff --git a/benchmark/vm_defined_method.yml b/benchmark/vm_defined_method.yml
new file mode 100644
index 0000000000..347e0cfd33
--- /dev/null
+++ b/benchmark/vm_defined_method.yml
@@ -0,0 +1,8 @@
+prelude: |
+  class Object
+    define_method(:m){}
+  end
+benchmark:
+  vm_defined_method: |
+    m; m; m; m; m; m; m; m;
+loop_count: 6000000
diff --git a/benchmark/vm_dstr.yml b/benchmark/vm_dstr.yml
new file mode 100644
index 0000000000..30c7a3193c
--- /dev/null
+++ b/benchmark/vm_dstr.yml
@@ -0,0 +1,6 @@
+prelude: |
+  x = y = 'z'
+benchmark:
+  vm_dstr: |
+    str = "foo#{x}bar#{y}baz"
+loop_count: 6000000
diff --git a/benchmark/vm_dstr_ary.rb b/benchmark/vm_dstr_ary.rb
new file mode 100644
index 0000000000..1d3aa3b97b
--- /dev/null
+++ b/benchmark/vm_dstr_ary.rb
@@ -0,0 +1,6 @@
+i = 0
+x = y = []
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_bool.rb b/benchmark/vm_dstr_bool.rb
new file mode 100644
index 0000000000..631ca54755
--- /dev/null
+++ b/benchmark/vm_dstr_bool.rb
@@ -0,0 +1,7 @@
+i = 0
+x = true
+y = false
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_class_module.rb b/benchmark/vm_dstr_class_module.rb
new file mode 100644
index 0000000000..becf0861c7
--- /dev/null
+++ b/benchmark/vm_dstr_class_module.rb
@@ -0,0 +1,10 @@
+i = 0
+class A; end unless defined?(A)
+module B; end unless defined?(B)
+x = A
+y = B
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
+
diff --git a/benchmark/vm_dstr_digit.rb b/benchmark/vm_dstr_digit.rb
new file mode 100644
index 0000000000..caaa395192
--- /dev/null
+++ b/benchmark/vm_dstr_digit.rb
@@ -0,0 +1,7 @@
+i = 0
+x = 0
+y = 9
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_int.rb b/benchmark/vm_dstr_int.rb
new file mode 100644
index 0000000000..ed380d7595
--- /dev/null
+++ b/benchmark/vm_dstr_int.rb
@@ -0,0 +1,5 @@
+i = 0
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{i}bar#{i}baz"
+end
diff --git a/benchmark/vm_dstr_nil.rb b/benchmark/vm_dstr_nil.rb
new file mode 100644
index 0000000000..ec4f5d6c67
--- /dev/null
+++ b/benchmark/vm_dstr_nil.rb
@@ -0,0 +1,6 @@
+i = 0
+x = y = nil
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_obj.rb b/benchmark/vm_dstr_obj.rb
new file mode 100644
index 0000000000..fb78637ead
--- /dev/null
+++ b/benchmark/vm_dstr_obj.rb
@@ -0,0 +1,6 @@
+i = 0
+x = y = Object.new
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_obj_def.rb b/benchmark/vm_dstr_obj_def.rb
new file mode 100644
index 0000000000..99ff7b98fb
--- /dev/null
+++ b/benchmark/vm_dstr_obj_def.rb
@@ -0,0 +1,8 @@
+i = 0
+o = Object.new
+def o.to_s; -""; end
+x = y = o
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_str.rb b/benchmark/vm_dstr_str.rb
new file mode 100644
index 0000000000..45fc107892
--- /dev/null
+++ b/benchmark/vm_dstr_str.rb
@@ -0,0 +1,6 @@
+i = 0
+x = y = ""
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_dstr_sym.rb b/benchmark/vm_dstr_sym.rb
new file mode 100644
index 0000000000..484b8f8150
--- /dev/null
+++ b/benchmark/vm_dstr_sym.rb
@@ -0,0 +1,6 @@
+i = 0
+x = y = :z
+while i<6_000_000 # benchmark loop 2
+  i += 1
+  str = "foo#{x}bar#{y}baz"
+end
diff --git a/benchmark/vm_ensure.yml b/benchmark/vm_ensure.yml
new file mode 100644
index 0000000000..4ea62f30de
--- /dev/null
+++ b/benchmark/vm_ensure.yml
@@ -0,0 +1,14 @@
+# Not utilizing loop_count since using it for this is too unstable for now
+benchmark:
+  vm_ensure: |
+    i = 0
+    while i<30_000_000
+      i += 1
+      begin
+        begin
+        ensure
+        end
+      ensure
+      end
+    end
+loop_count: 1
diff --git a/benchmark/vm_eval.yml b/benchmark/vm_eval.yml
new file mode 100644
index 0000000000..7ba1a8d1de
--- /dev/null
+++ b/benchmark/vm_eval.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_eval: |
+    eval("1")
+loop_count: 6000000
diff --git a/benchmark/vm_fiber_allocate.yml b/benchmark/vm_fiber_allocate.yml
new file mode 100644
index 0000000000..b5a54e1ddf
--- /dev/null
+++ b/benchmark/vm_fiber_allocate.yml
@@ -0,0 +1,8 @@
+prelude: |
+  # Disable GC to see raw throughput:
+  GC.disable
+benchmark:
+  vm_fiber_allocate: |
+    fiber = Fiber.new{Fiber.yield}
+    fiber.resume
+loop_count: 100000
diff --git a/benchmark/vm_fiber_count.yml b/benchmark/vm_fiber_count.yml
new file mode 100644
index 0000000000..b83d3152d4
--- /dev/null
+++ b/benchmark/vm_fiber_count.yml
@@ -0,0 +1,10 @@
+# On Linux, you will need to increase the maximum number of memory maps:
+# sudo sysctl -w vm.max_map_count=200000
+prelude: |
+  fibers = []
+benchmark:
+  vm_fiber_count: |
+    fiber = Fiber.new{Fiber.yield}
+    fibers << fiber
+    fiber.resume
+loop_count: 100000
diff --git a/benchmark/vm_fiber_reuse.yml b/benchmark/vm_fiber_reuse.yml
new file mode 100644
index 0000000000..4ca41085b1
--- /dev/null
+++ b/benchmark/vm_fiber_reuse.yml
@@ -0,0 +1,14 @@
+prelude: |
+  GC.disable
+  fibers = []
+benchmark:
+  vm_fiber_reuse: |
+    1024.times do
+      fiber = Fiber.new{Fiber.yield}
+      fibers << fiber
+      fiber.resume
+    end
+
+    fibers.clear
+    GC.start
+loop_count: 200
diff --git a/benchmark/vm_fiber_reuse_gc.yml b/benchmark/vm_fiber_reuse_gc.yml
new file mode 100644
index 0000000000..892622f121
--- /dev/null
+++ b/benchmark/vm_fiber_reuse_gc.yml
@@ -0,0 +1,12 @@
+# https://bugs.ruby-lang.org/issues/16009
+prelude: |
+  fibers = []
+benchmark:
+  vm_fiber_reuse_gc: |
+    2000.times do
+      fiber = Fiber.new{Fiber.yield}
+      fibers << fiber
+      fiber.resume
+    end
+    fibers.clear
+loop_count: 100
diff --git a/benchmark/vm_fiber_switch.yml b/benchmark/vm_fiber_switch.yml
new file mode 100644
index 0000000000..3de36b66eb
--- /dev/null
+++ b/benchmark/vm_fiber_switch.yml
@@ -0,0 +1,9 @@
+prelude: |
+  # based on benchmark for [ruby-core:65518] [Feature #10341] by Knut Franke
+  fib = Fiber.new do
+    loop { Fiber.yield }
+  end
+benchmark:
+  vm_fiber_switch: |
+    fib.resume
+loop_count: 20000000
diff --git a/benchmark/vm_float_simple.yml b/benchmark/vm_float_simple.yml
new file mode 100644
index 0000000000..92f5fd52ab
--- /dev/null
+++ b/benchmark/vm_float_simple.yml
@@ -0,0 +1,8 @@
+prelude: |
+  f = 0.0
+benchmark:
+  vm_float_simple: |
+    f += 0.1; f -= 0.1
+    f += 0.1; f -= 0.1
+    f += 0.1; f -= 0.1
+loop_count: 30000000
diff --git a/benchmark/vm_freezeobj.yml b/benchmark/vm_freezeobj.yml
new file mode 100644
index 0000000000..69a795a354
--- /dev/null
+++ b/benchmark/vm_freezeobj.yml
@@ -0,0 +1,6 @@
+prelude: |
+ objs = 100000.times.map { Object.new }
+benchmark:
+  vm_freeze_obj: |
+    objs.map(&:freeze)
+loop_count: 600
diff --git a/benchmark/vm_freezestring.yml b/benchmark/vm_freezestring.yml
new file mode 100644
index 0000000000..facc9aa043
--- /dev/null
+++ b/benchmark/vm_freezestring.yml
@@ -0,0 +1,10 @@
+prelude: |
+  class String
+    def freeze
+      -self
+    end
+  end
+benchmark:
+  vm_freezestring: |
+    "tXnL1BP5T1WPXMjuFNLQtallEtRcay1t2lHtJSrlVsDgvunlbtfpr/DGdH0NGYE9".freeze
+loop_count: 6000000
diff --git a/benchmark/vm3_gc.rb b/benchmark/vm_gc.rb
index e668026915..e668026915 100644
--- a/benchmark/vm3_gc.rb
+++ b/benchmark/vm_gc.rb
diff --git a/benchmark/vm3_gc_old_full.rb b/benchmark/vm_gc_old_full.rb
index cfdfc8c5a5..cfdfc8c5a5 100644
--- a/benchmark/vm3_gc_old_full.rb
+++ b/benchmark/vm_gc_old_full.rb
diff --git a/benchmark/vm3_gc_old_immediate.rb b/benchmark/vm_gc_old_immediate.rb
index ad22feb655..ad22feb655 100644
--- a/benchmark/vm3_gc_old_immediate.rb
+++ b/benchmark/vm_gc_old_immediate.rb
diff --git a/benchmark/vm3_gc_old_lazy.rb b/benchmark/vm_gc_old_lazy.rb
index b74d44baf1..b74d44baf1 100644
--- a/benchmark/vm3_gc_old_lazy.rb
+++ b/benchmark/vm_gc_old_lazy.rb
diff --git a/benchmark/vm_gc_short_lived.yml b/benchmark/vm_gc_short_lived.yml
new file mode 100644
index 0000000000..29c803fee3
--- /dev/null
+++ b/benchmark/vm_gc_short_lived.yml
@@ -0,0 +1,9 @@
+benchmark:
+  vm_gc_short_lived: |
+    a = '' # short-lived String
+    b = ''
+    c = ''
+    d = ''
+    e = ''
+    f = ''
+loop_count: 30000000
diff --git a/benchmark/vm_gc_short_with_complex_long.yml b/benchmark/vm_gc_short_with_complex_long.yml
new file mode 100644
index 0000000000..4b6c3ed7b9
--- /dev/null
+++ b/benchmark/vm_gc_short_with_complex_long.yml
@@ -0,0 +1,25 @@
+prelude: |
+  def nested_hash h, n
+    if n == 0
+      ''
+    else
+      10.times{
+        h[Object.new] = nested_hash(h, n-1)
+      }
+    end
+  end
+
+  long_lived = Hash.new
+  nested_hash long_lived, 6
+
+  GC.start
+  GC.start
+benchmark:
+  vm_gc_short_with_complex_long: |
+    a = '' # short-lived String
+    b = ''
+    c = ''
+    d = ''
+    e = ''
+    f = ''
+loop_count: 30000000
diff --git a/benchmark/vm_gc_short_with_long.yml b/benchmark/vm_gc_short_with_long.yml
new file mode 100644
index 0000000000..03ba0f95a9
--- /dev/null
+++ b/benchmark/vm_gc_short_with_long.yml
@@ -0,0 +1,13 @@
+prelude: |
+  long_lived = Array.new(1_000_000){|i| "#{i}"}
+  GC.start
+  GC.start
+benchmark:
+  vm_gc_short_with_long: |
+    a = '' # short-lived String
+    b = ''
+    c = ''
+    d = ''
+    e = ''
+    f = ''
+loop_count: 30000000
diff --git a/benchmark/vm_gc_short_with_symbol.yml b/benchmark/vm_gc_short_with_symbol.yml
new file mode 100644
index 0000000000..129b8bf4ed
--- /dev/null
+++ b/benchmark/vm_gc_short_with_symbol.yml
@@ -0,0 +1,13 @@
+prelude: |
+  50_000.times{|i| sym = "sym#{i}".to_sym}
+  GC.start
+  GC.start
+benchmark:
+  vm_gc_short_with_symbol: |
+    a = '' # short-lived String
+    b = ''
+    c = ''
+    d = ''
+    e = ''
+    f = ''
+loop_count: 30000000
diff --git a/benchmark/vm_gc_wb_ary.yml b/benchmark/vm_gc_wb_ary.yml
new file mode 100644
index 0000000000..e3293e72d0
--- /dev/null
+++ b/benchmark/vm_gc_wb_ary.yml
@@ -0,0 +1,12 @@
+prelude: |
+  short_lived_ary = []
+
+  if RUBY_VERSION >= "2.2.0"
+    GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true)
+  end
+
+  short_lived = ''
+benchmark:
+  vm_gc_wb_ary: |
+    short_lived_ary[0] = short_lived # write barrier
+loop_count: 30000000
diff --git a/benchmark/vm_gc_wb_ary_promoted.yml b/benchmark/vm_gc_wb_ary_promoted.yml
new file mode 100644
index 0000000000..003995945b
--- /dev/null
+++ b/benchmark/vm_gc_wb_ary_promoted.yml
@@ -0,0 +1,15 @@
+prelude: |
+  long_lived = []
+
+  if RUBY_VERSION > "2.2.0"
+    3.times{ GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true) }
+  elsif
+    GC.start
+  end
+
+  short_lived = ''
+
+benchmark:
+  vm_gc_wb_ary_promoted: |
+    long_lived[0] = short_lived # write barrier
+loop_count: 30000000
diff --git a/benchmark/vm_gc_wb_obj.yml b/benchmark/vm_gc_wb_obj.yml
new file mode 100644
index 0000000000..a2a2ce2d18
--- /dev/null
+++ b/benchmark/vm_gc_wb_obj.yml
@@ -0,0 +1,15 @@
+prelude: |
+  class C
+    attr_accessor :foo
+  end
+  short_lived_obj = C.new
+
+  if RUBY_VERSION >= "2.2.0"
+    GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true)
+  end
+
+  short_lived = ''
+benchmark:
+  vm_gc_wb_obj: |
+    short_lived_obj.foo = short_lived # write barrier
+loop_count: 30000000
diff --git a/benchmark/vm_gc_wb_obj_promoted.yml b/benchmark/vm_gc_wb_obj_promoted.yml
new file mode 100644
index 0000000000..00a454ba72
--- /dev/null
+++ b/benchmark/vm_gc_wb_obj_promoted.yml
@@ -0,0 +1,17 @@
+prelude: |
+  class C
+    attr_accessor :foo
+  end
+  long_lived = C.new
+
+  if RUBY_VERSION >= "2.2.0"
+    3.times{ GC.start(full_mark: false, immediate_mark: true, immediate_sweep: true) }
+  elsif
+    GC.start
+  end
+
+  short_lived = ''
+benchmark:
+  vm_gc_wb_obj_promoted: |
+    long_lived.foo = short_lived # write barrier
+loop_count: 30000000
diff --git a/benchmark/vm_iclass_super.yml b/benchmark/vm_iclass_super.yml
new file mode 100644
index 0000000000..21bb7db247
--- /dev/null
+++ b/benchmark/vm_iclass_super.yml
@@ -0,0 +1,20 @@
+prelude: |
+  class C
+    def m
+      1
+    end
+
+    ("A".."M").each do |module_name|
+      eval <<-EOM
+          module #{module_name}
+            def m; super; end
+          end
+          prepend #{module_name}
+      EOM
+    end
+  end
+
+  obj = C.new
+benchmark:
+  vm_iclass_super: obj.m
+loop_count: 6000000
diff --git a/benchmark/vm_ivar.yml b/benchmark/vm_ivar.yml
new file mode 100644
index 0000000000..119531d5ef
--- /dev/null
+++ b/benchmark/vm_ivar.yml
@@ -0,0 +1,6 @@
+prelude: "@a = 1\n"
+benchmark:
+  vm_ivar: |
+    j = @a
+    k = @a
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_embedded_obj_init.yml b/benchmark/vm_ivar_embedded_obj_init.yml
new file mode 100644
index 0000000000..74fe20a630
--- /dev/null
+++ b/benchmark/vm_ivar_embedded_obj_init.yml
@@ -0,0 +1,14 @@
+prelude: |
+  class C
+    def set_ivars
+      @a = nil
+      @b = nil
+      @c = nil
+    end
+  end
+
+  c = C.new
+benchmark:
+  vm_ivar_embedded_obj_init: |
+    c.set_ivars
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_extended_obj_init.yml b/benchmark/vm_ivar_extended_obj_init.yml
new file mode 100644
index 0000000000..f054bab282
--- /dev/null
+++ b/benchmark/vm_ivar_extended_obj_init.yml
@@ -0,0 +1,16 @@
+prelude: |
+  class C
+    def set_ivars
+      @a = nil
+      @b = nil
+      @c = nil
+      @d = nil
+      @e = nil
+    end
+  end
+
+  c = C.new
+benchmark:
+  vm_ivar_extended_obj_init: |
+    c.set_ivars
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_generic_get.yml b/benchmark/vm_ivar_generic_get.yml
new file mode 100644
index 0000000000..dae2d37671
--- /dev/null
+++ b/benchmark/vm_ivar_generic_get.yml
@@ -0,0 +1,17 @@
+prelude: |
+  class C < Array
+    attr_reader :a, :b, :c
+    def initialize
+      @a = nil
+      @b = nil
+      @c = nil
+    end
+  end
+
+  c = C.new
+benchmark:
+  vm_ivar_generic_get: |
+    c.a
+    c.b
+    c.c
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_generic_set.yml b/benchmark/vm_ivar_generic_set.yml
new file mode 100644
index 0000000000..102a6577fb
--- /dev/null
+++ b/benchmark/vm_ivar_generic_set.yml
@@ -0,0 +1,14 @@
+prelude: |
+  class C < Array
+    def set_ivars
+      @a = nil
+      @b = nil
+      @c = nil
+    end
+  end
+
+  c = C.new
+benchmark:
+  vm_ivar_generic_set: |
+    c.set_ivars
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_get.yml b/benchmark/vm_ivar_get.yml
new file mode 100644
index 0000000000..1e0dad665f
--- /dev/null
+++ b/benchmark/vm_ivar_get.yml
@@ -0,0 +1,100 @@
+prelude: |
+  class Example
+    def initialize
+      @levar = 1
+      @v0 = 1
+      @v1 = 2
+      @v3 = 3
+    end
+
+    def get_value_loop
+      sum = 0
+
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        i += 1
+      end
+
+      return sum
+    end
+
+    @levar = 1
+    @v0 = 1
+    @v1 = 2
+    @v3 = 3
+
+    def self.get_value_loop
+      sum = 0
+
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        i += 1
+      end
+
+      return sum
+    end
+  end
+
+  class GenExample < Time
+    def initialize
+      @levar = 1
+      @v0 = 1
+      @v1 = 2
+      @v3 = 3
+    end
+
+    def get_value_loop
+      sum = 0
+
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        i += 1
+      end
+
+      return sum
+    end
+  end
+
+  obj = Example.new
+  gen = GenExample.new
+benchmark:
+  vm_ivar_get_on_obj: |
+    obj.get_value_loop
+  vm_ivar_get_on_class: |
+    Example.get_value_loop
+  vm_ivar_get_on_generic: |
+    gen.get_value_loop
+loop_count: 100
diff --git a/benchmark/vm_ivar_get_unintialized.yml b/benchmark/vm_ivar_get_unintialized.yml
new file mode 100644
index 0000000000..a1ccfb06ce
--- /dev/null
+++ b/benchmark/vm_ivar_get_unintialized.yml
@@ -0,0 +1,12 @@
+prelude: |
+  class Example
+    def read
+      @uninitialized
+    end
+  end
+
+  obj = Example.new
+benchmark:
+  vm_ivar_get_uninitialized: |
+    obj.read
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_ic_miss.yml b/benchmark/vm_ivar_ic_miss.yml
new file mode 100644
index 0000000000..944fb1a9e6
--- /dev/null
+++ b/benchmark/vm_ivar_ic_miss.yml
@@ -0,0 +1,20 @@
+prelude: |
+  class Foo
+    def initialize diverge
+      if diverge
+        @a = 1
+      end
+
+      @a0 = @a1 = @a2 = @a3 = @a4 = @a5 = @a6 = @a7 = @a8 = @a9 = @a10 = @a11 = @a12 = @a13 = @a14 = @a15 = @a16 = @a17 = @a18 = @a19 = @a20 = @a21 = @a22 = @a23 = @a24 = @a25 = @a26 = @a27 = @a28 = @a29 = @a30 = @a31 = @a32 = @a33 = @a34 = @a35 = @a36 = @a37 = @a38 = @a39 = @a40 = @a41 = @a42 = @a43 = @a44 = @a45 = @a46 = @a47 = @a48 = @a49 = @a50 = @a51 = @a52 = @a53 = @a54 = @a55 = @a56 = @a57 = @a58 = @a59 = @a60 = @a61 = @a62 = @a63 = @a64 = @a65 = @a66 = @a67 = @a68 = @a69 = @a70 = @a71 = @a72 = @a73 = @a74 = @b = 1
+    end
+
+    def b; @b; end
+  end
+
+  a = Foo.new false
+  b = Foo.new true
+benchmark:
+  vm_ivar_ic_miss: |
+    a.b
+    b.b
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_lazy_set.yml b/benchmark/vm_ivar_lazy_set.yml
new file mode 100644
index 0000000000..7372ffcfbc
--- /dev/null
+++ b/benchmark/vm_ivar_lazy_set.yml
@@ -0,0 +1,12 @@
+prelude: |
+  class Example
+    def lazy_set
+      @uninitialized ||= 123
+    end
+  end
+
+  objs = 10000000.times.map { Example.new }
+benchmark:
+  vm_ivar_lazy_set: |
+    objs.each(&:lazy_set)
+loop_count: 1
diff --git a/benchmark/vm_ivar_memoize.yml b/benchmark/vm_ivar_memoize.yml
new file mode 100644
index 0000000000..90f6b07f05
--- /dev/null
+++ b/benchmark/vm_ivar_memoize.yml
@@ -0,0 +1,85 @@
+prelude: |
+  IVARS = 60
+  class Record
+    def initialize(offset = false)
+      @offset = 1 if offset
+      @first = 0
+      IVARS.times do |i|
+        instance_variable_set("@ivar_#{i}", i)
+      end
+    end
+
+    def first
+      @first
+    end
+
+    def lazy_set
+      @lazy_set ||= 123
+    end
+
+    def undef
+      @undef
+    end
+  end
+
+  Record.new # Need one alloc to right size
+
+  BASE = Record.new
+  LAZY = Record.new
+  LAZY.lazy_set
+
+  class Miss < Record
+    @first = 0
+    IVARS.times do |i|
+      instance_variable_set("@i_#{i}", i)
+    end
+  end
+
+  Miss.new # Need one alloc to right size
+  MISS = Miss.new
+
+  DIVERGENT = Record.new(true)
+
+benchmark:
+  vm_ivar_stable_shape: |
+    BASE.first
+    BASE.first
+    BASE.first
+    BASE.first
+    BASE.first
+    BASE.first
+  vm_ivar_memoize_unstable_shape: |
+    BASE.first
+    LAZY.first
+    BASE.first
+    LAZY.first
+    BASE.first
+    LAZY.first
+  vm_ivar_memoize_unstable_shape_miss: |
+    BASE.first
+    MISS.first
+    BASE.first
+    MISS.first
+    BASE.first
+    MISS.first
+  vm_ivar_unstable_undef: |
+    BASE.undef
+    LAZY.undef
+    BASE.undef
+    LAZY.undef
+    BASE.undef
+    LAZY.undef
+  vm_ivar_divergent_shape: |
+    BASE.first
+    DIVERGENT.first
+    BASE.first
+    DIVERGENT.first
+    BASE.first
+    DIVERGENT.first
+  vm_ivar_divergent_shape_imbalanced: |
+    BASE.first
+    DIVERGENT.first
+    DIVERGENT.first
+    DIVERGENT.first
+    DIVERGENT.first
+    DIVERGENT.first
diff --git a/benchmark/vm_ivar_of_class.yml b/benchmark/vm_ivar_of_class.yml
new file mode 100644
index 0000000000..172e28b2fd
--- /dev/null
+++ b/benchmark/vm_ivar_of_class.yml
@@ -0,0 +1,12 @@
+prelude: |
+  class C
+    @a = 1
+    def self.a
+      _a = @a; _a = @a; _a = @a; _a = @a; _a = @a;
+      _a = @a; _a = @a; _a = @a; _a = @a; _a = @a;
+    end
+  end
+benchmark:
+  vm_ivar_of_class: |
+    a = C.a
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_of_class_set.yml b/benchmark/vm_ivar_of_class_set.yml
new file mode 100644
index 0000000000..2ea5199423
--- /dev/null
+++ b/benchmark/vm_ivar_of_class_set.yml
@@ -0,0 +1,11 @@
+prelude: |
+  class C
+    @a = 1
+    def self.a o
+      @a = o; @a = o; @a = o; @a = o; @a = o; @a = o;
+    end
+  end
+benchmark:
+  vm_ivar_of_class_set: |
+    a = C.a(nil)
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_set.yml b/benchmark/vm_ivar_set.yml
new file mode 100644
index 0000000000..8bbb60043b
--- /dev/null
+++ b/benchmark/vm_ivar_set.yml
@@ -0,0 +1,5 @@
+benchmark:
+  vm_ivar_set: |
+    @a = 1
+    @b = 2
+loop_count: 30000000
diff --git a/benchmark/vm_ivar_set_on_instance.yml b/benchmark/vm_ivar_set_on_instance.yml
new file mode 100644
index 0000000000..6ce53a86ec
--- /dev/null
+++ b/benchmark/vm_ivar_set_on_instance.yml
@@ -0,0 +1,94 @@
+prelude: |
+  class TheClass
+    def initialize
+      @levar = 1
+      @v0 = 1
+      @v1 = 2
+      @v3 = 3
+    end
+
+    def set_value_loop
+      # 100k
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        i += 1
+      end
+    end
+  end
+
+  class Generic < Time
+    def initialize
+      @levar = 1
+      @v0 = 1
+      @v1 = 2
+      @v3 = 3
+    end
+
+    def set_value_loop
+      # 100k
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        i += 1
+      end
+    end
+  end
+
+  obj = TheClass.new
+  gen_obj = Generic.new
+
+  class SomeClass
+    @levar = 1
+    @v0 = 1
+    @v1 = 2
+    @v3 = 3
+
+    def self.set_value_loop
+      # 100k
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        i += 1
+      end
+    end
+  end
+
+benchmark:
+  vm_ivar_set_on_instance: |
+    obj.set_value_loop
+  vm_ivar_set_on_generic: |
+    gen_obj.set_value_loop
+  vm_ivar_set_on_class: |
+    SomeClass.set_value_loop
+loop_count: 100
diff --git a/benchmark/vm_ivar_set_subclass.yml b/benchmark/vm_ivar_set_subclass.yml
new file mode 100644
index 0000000000..bc8bf5bf6b
--- /dev/null
+++ b/benchmark/vm_ivar_set_subclass.yml
@@ -0,0 +1,20 @@
+prelude: |
+  class A
+    def set_ivars
+      @a = nil
+      @b = nil
+      @c = nil
+      @d = nil
+      @e = nil
+    end
+  end
+  class B < A; end
+  class C < A; end
+
+  b = B.new
+  c = C.new
+benchmark:
+  vm_ivar_init_subclass: |
+    b.set_ivars
+    c.set_ivars
+loop_count: 3000000
diff --git a/benchmark/vm_length.yml b/benchmark/vm_length.yml
new file mode 100644
index 0000000000..5fd94e7d86
--- /dev/null
+++ b/benchmark/vm_length.yml
@@ -0,0 +1,8 @@
+prelude: |
+  a = 'abc'
+  b = [1, 2, 3]
+benchmark:
+  vm_length: |
+    a.length
+    b.length
+loop_count: 30000000
diff --git a/benchmark/vm_lvar_cond_set.yml b/benchmark/vm_lvar_cond_set.yml
new file mode 100644
index 0000000000..1845f9d12e
--- /dev/null
+++ b/benchmark/vm_lvar_cond_set.yml
@@ -0,0 +1,8 @@
+benchmark:
+  vm_lvar_cond_set: |
+    a ||= 1
+    b ||= 1
+    c ||= 1
+    d ||= 1
+    nil
+loop_count: 30000000
diff --git a/benchmark/vm_lvar_init.yml b/benchmark/vm_lvar_init.yml
new file mode 100644
index 0000000000..70a9b1c0ca
--- /dev/null
+++ b/benchmark/vm_lvar_init.yml
@@ -0,0 +1,21 @@
+# while loop cost is not removed because `i` is used in the script
+benchmark:
+  vm_lvar_init: |
+    def m v
+      unless v
+        # unreachable code
+        v1 = v2 = v3 = v4 = v5 = v6 = v7 = v8 = v9 = v10 =
+        v11 = v12 = v13 = v14 = v15 = v16 = v17 = v18 = v19 = v20 =
+        v21 = v22 = v23 = v24 = v25 = v26 = v27 = v28 = v29 = v30 =
+        v31 = v32 = v33 = v34 = v35 = v36 = v37 = v38 = v39 = v40 =
+        v41 = v42 = v43 = v44 = v45 = v46 = v47 = v48 = v49 = v50 = 1
+      end
+    end
+
+    i = 0
+
+    while i<30_000_000
+      i += 1
+      m i
+    end
+loop_count: 1
diff --git a/benchmark/vm_lvar_set.yml b/benchmark/vm_lvar_set.yml
new file mode 100644
index 0000000000..f29f763d81
--- /dev/null
+++ b/benchmark/vm_lvar_set.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_lvar_set: |
+    a = b = c = d = e = f = g = h = j = k = l = m = n = o = p = q = r = 1
+loop_count: 30000000
diff --git a/benchmark/vm_method.yml b/benchmark/vm_method.yml
new file mode 100644
index 0000000000..d45e4ec572
--- /dev/null
+++ b/benchmark/vm_method.yml
@@ -0,0 +1,8 @@
+prelude: |
+  def m
+    nil
+  end
+benchmark:
+  vm_method: |
+    m; m; m; m; m; m; m; m;
+loop_count: 6000000
diff --git a/benchmark/vm_method_missing.yml b/benchmark/vm_method_missing.yml
new file mode 100644
index 0000000000..3da456c0bb
--- /dev/null
+++ b/benchmark/vm_method_missing.yml
@@ -0,0 +1,11 @@
+prelude: |
+  class C
+    def method_missing mid
+    end
+  end
+
+  obj = C.new
+benchmark:
+  vm_method_missing: |
+    obj.m; obj.m; obj.m; obj.m; obj.m; obj.m; obj.m; obj.m;
+loop_count: 6000000
diff --git a/benchmark/vm_method_splat_calls.yml b/benchmark/vm_method_splat_calls.yml
new file mode 100644
index 0000000000..f2f366e99c
--- /dev/null
+++ b/benchmark/vm_method_splat_calls.yml
@@ -0,0 +1,13 @@
+prelude: |
+  def f(x=0, y: 0) end
+  a = [1]
+  ea = []
+  kw = {y: 1}
+  b = lambda{}
+benchmark:
+  arg_splat: "f(1, *ea)"
+  arg_splat_block: "f(1, *ea, &b)"
+  splat_kw_splat: "f(*a, **kw)"
+  splat_kw_splat_block: "f(*a, **kw, &b)"
+  splat_kw: "f(*a, y: 1)"
+  splat_kw_block: "f(*a, y: 1, &b)"
diff --git a/benchmark/vm_method_splat_calls2.yml b/benchmark/vm_method_splat_calls2.yml
new file mode 100644
index 0000000000..d33dcd7e8b
--- /dev/null
+++ b/benchmark/vm_method_splat_calls2.yml
@@ -0,0 +1,27 @@
+prelude: |
+  def named_arg_splat(*a) end
+  def named_arg_kw_splat(*a, **kw) end
+  def anon_arg_splat(*) end
+  def anon_kw_splat(**) end
+  def anon_arg_kw_splat(*, **) end
+  def anon_fw_to_named(*, **) named_arg_kw_splat(*, **) end
+  def fw_to_named(...) named_arg_kw_splat(...) end
+  def fw_to_anon_to_named(...) anon_fw_to_named(...) end
+  def fw_no_kw(...) named_arg_splat(...) end
+  a = [1]
+  kw = {y: 1}
+benchmark:
+  named_multi_arg_splat: "named_arg_splat(*a, *a)"
+  named_post_splat: "named_arg_splat(*a, a)"
+  anon_arg_splat: "anon_arg_splat(*a)"
+  anon_arg_kw_splat: "anon_arg_kw_splat(*a, **kw)"
+  anon_multi_arg_splat: "anon_arg_splat(*a, *a)"
+  anon_post_splat: "anon_arg_splat(*a, a)"
+  anon_kw_splat: "anon_kw_splat(**kw)"
+  anon_fw_to_named_splat: "anon_fw_to_named(*a, **kw)"
+  anon_fw_to_named_no_splat: "anon_fw_to_named(1, y: 1)"
+  fw_to_named_splat: "fw_to_named(*a, **kw)"
+  fw_to_named_no_splat: "fw_to_named(1, y: 1)"
+  fw_to_anon_to_named_splat: "fw_to_anon_to_named(*a, **kw)"
+  fw_to_anon_to_named_no_splat: "fw_to_anon_to_named(1, y: 1)"
+  fw_no_kw: "fw_no_kw(1, 2)"
diff --git a/benchmark/vm_method_with_block.yml b/benchmark/vm_method_with_block.yml
new file mode 100644
index 0000000000..281a481394
--- /dev/null
+++ b/benchmark/vm_method_with_block.yml
@@ -0,0 +1,8 @@
+prelude: |
+  def m
+    nil
+  end
+benchmark:
+  vm_method_with_block: |
+    m{}; m{}; m{}; m{}; m{}; m{}; m{}; m{};
+loop_count: 6000000
diff --git a/benchmark/vm_module_ann_const_set.yml b/benchmark/vm_module_ann_const_set.yml
new file mode 100644
index 0000000000..243229ba4a
--- /dev/null
+++ b/benchmark/vm_module_ann_const_set.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_module_ann_const_set: |
+    Module.new.const_set(:X, Module.new)
+loop_count: 6000000
diff --git a/benchmark/vm_module_const_set.yml b/benchmark/vm_module_const_set.yml
new file mode 100644
index 0000000000..e5a24181a9
--- /dev/null
+++ b/benchmark/vm_module_const_set.yml
@@ -0,0 +1,8 @@
+prelude: |
+  module M
+  end
+  $VERBOSE = nil
+benchmark:
+  vm_module_const_set: |
+    M.const_set(:X, Module.new)
+loop_count: 6000000
diff --git a/benchmark/vm_mutex.yml b/benchmark/vm_mutex.yml
new file mode 100644
index 0000000000..abcf1e28ce
--- /dev/null
+++ b/benchmark/vm_mutex.yml
@@ -0,0 +1,8 @@
+prelude: |
+  require 'thread'
+
+  m = Thread::Mutex.new
+benchmark:
+  vm_mutex: |
+    m.synchronize{}
+loop_count: 6000000
diff --git a/benchmark/vm_neq.yml b/benchmark/vm_neq.yml
new file mode 100644
index 0000000000..fb04d15ae8
--- /dev/null
+++ b/benchmark/vm_neq.yml
@@ -0,0 +1,7 @@
+prelude: |
+  obj1 = Object.new
+  obj2 = Object.new
+benchmark:
+  vm_neq: |
+    obj1 != obj2
+loop_count: 30000000
diff --git a/benchmark/vm_newlambda.yml b/benchmark/vm_newlambda.yml
new file mode 100644
index 0000000000..0b9787d91a
--- /dev/null
+++ b/benchmark/vm_newlambda.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_newlambda: |
+    lambda {}
+loop_count: 6000000
diff --git a/benchmark/vm_not.yml b/benchmark/vm_not.yml
new file mode 100644
index 0000000000..c68dde3c50
--- /dev/null
+++ b/benchmark/vm_not.yml
@@ -0,0 +1,6 @@
+prelude: |
+  obj = Object.new
+benchmark:
+  vm_not: |
+    !obj
+loop_count: 30000000
diff --git a/benchmark/vm_poly_method.yml b/benchmark/vm_poly_method.yml
new file mode 100644
index 0000000000..dd2f4e71de
--- /dev/null
+++ b/benchmark/vm_poly_method.yml
@@ -0,0 +1,24 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_poly_method: |
+    class C1
+      def m
+        1
+      end
+    end
+    class C2
+      def m
+        2
+      end
+    end
+
+    o1 = C1.new
+    o2 = C2.new
+
+    i = 0
+    while i<6_000_000
+      o = (i % 2 == 0) ? o1 : o2
+      o.m; o.m; o.m; o.m; o.m; o.m; o.m; o.m
+      i += 1
+    end
+loop_count: 1
diff --git a/benchmark/vm_poly_method_ov.yml b/benchmark/vm_poly_method_ov.yml
new file mode 100644
index 0000000000..bca1b62729
--- /dev/null
+++ b/benchmark/vm_poly_method_ov.yml
@@ -0,0 +1,24 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_poly_method_ov: |
+    class C1
+      def m
+        1
+      end
+    end
+    class C2
+      def m
+        2
+      end
+    end
+
+    o1 = C1.new
+    o2 = C2.new
+
+    i = 0
+    while i<6_000_000
+      o = (i % 2 == 0) ? o1 : o2
+    #  o.m; o.m; o.m; o.m; o.m; o.m; o.m; o.m
+      i += 1
+    end
+loop_count: 1
diff --git a/benchmark/vm_poly_same_method.yml b/benchmark/vm_poly_same_method.yml
new file mode 100644
index 0000000000..6c5404ac84
--- /dev/null
+++ b/benchmark/vm_poly_same_method.yml
@@ -0,0 +1,25 @@
+prelude: |
+  module AR; end
+  class AR::Base
+    def create_or_update
+      nil
+    end
+    def save
+      create_or_update
+    end
+  end
+  class Foo < AR::Base; end
+  class Bar < AR::Base; end
+  o1 = Foo.new
+  o2 = Bar.new
+benchmark:
+  vm_poly_same_method: |
+    o1.save; o2.save;
+    o1.save; o2.save;
+    o1.save; o2.save;
+    o1.save; o2.save;
+    o1.save; o2.save;
+    o1.save; o2.save;
+    o1.save; o2.save;
+    o1.save; o2.save;
+loop_count: 6000000
diff --git a/benchmark/vm_poly_singleton.yml b/benchmark/vm_poly_singleton.yml
new file mode 100644
index 0000000000..c7923160fb
--- /dev/null
+++ b/benchmark/vm_poly_singleton.yml
@@ -0,0 +1,18 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_poly_singleton: |
+    class C1
+      def m; 1; end
+    end
+
+    o1 = C1.new
+    o2 = C1.new
+    o2.singleton_class
+
+    i = 0
+    while i<6_000_000 # benchmark loop 2
+      o = (i % 2 == 0) ? o1 : o2
+      o.m; o.m; o.m; o.m; o.m; o.m; o.m; o.m
+      i += 1
+    end
+loop_count: 1
diff --git a/benchmark/vm_proc.yml b/benchmark/vm_proc.yml
new file mode 100644
index 0000000000..2f8de6c272
--- /dev/null
+++ b/benchmark/vm_proc.yml
@@ -0,0 +1,12 @@
+prelude: |
+  def m &b
+    b
+  end
+
+  pr = m{
+    a = 1
+  }
+benchmark:
+  vm_proc: |
+    pr.call
+loop_count: 6000000
diff --git a/benchmark/vm_raise1.yml b/benchmark/vm_raise1.yml
new file mode 100644
index 0000000000..247d9f70ee
--- /dev/null
+++ b/benchmark/vm_raise1.yml
@@ -0,0 +1,16 @@
+prelude: |
+  def rec n
+    if n > 0
+      rec n-1
+    else
+      raise
+    end
+  end
+benchmark:
+  vm_raise1: |
+    begin
+      rec 1
+    rescue
+      # ignore
+    end
+loop_count: 6000000
diff --git a/benchmark/vm_raise2.yml b/benchmark/vm_raise2.yml
new file mode 100644
index 0000000000..f0fa047b3c
--- /dev/null
+++ b/benchmark/vm_raise2.yml
@@ -0,0 +1,16 @@
+prelude: |
+  def rec n
+    if n > 0
+      rec n-1
+    else
+      raise
+    end
+  end
+benchmark:
+  vm_raise2: |
+    begin
+      rec 10
+    rescue
+      # ignore
+    end
+loop_count: 6000000
diff --git a/benchmark/vm_regexp.yml b/benchmark/vm_regexp.yml
new file mode 100644
index 0000000000..80541332b1
--- /dev/null
+++ b/benchmark/vm_regexp.yml
@@ -0,0 +1,14 @@
+prelude: |
+  str = 'xxxhogexxx'
+benchmark:
+  vm_regexp: |
+    /hoge/ =~ str
+  vm_regexp_alternating: |
+    /hoge/ =~ str
+    /huge/ =~ str
+  vm_regexp_invert: |
+    str =~ /hoge/
+  vm_regexp_invert_alternating: |
+    str =~ /hoge/
+    str =~ /huge/
+loop_count: 6000000
diff --git a/benchmark/vm_rescue.yml b/benchmark/vm_rescue.yml
new file mode 100644
index 0000000000..b4a0af521f
--- /dev/null
+++ b/benchmark/vm_rescue.yml
@@ -0,0 +1,6 @@
+benchmark:
+  vm_rescue: |
+    begin
+    rescue
+    end
+loop_count: 30000000
diff --git a/benchmark/vm_send.yml b/benchmark/vm_send.yml
new file mode 100644
index 0000000000..f31bc7ac89
--- /dev/null
+++ b/benchmark/vm_send.yml
@@ -0,0 +1,14 @@
+prelude: |
+  class C
+    def m
+    end
+  end
+
+  o = C.new
+  m = :m
+benchmark:
+  vm_send: |
+    o.__send__ :m
+  vm_send_var: |
+    o.__send__ m
+loop_count: 6000000
diff --git a/benchmark/vm_send_cfunc.yml b/benchmark/vm_send_cfunc.yml
new file mode 100644
index 0000000000..6f12b65176
--- /dev/null
+++ b/benchmark/vm_send_cfunc.yml
@@ -0,0 +1,14 @@
+prelude: |
+  ary = []
+  kw = {a: 1}
+  empty_kw = {}
+  kw_ary = [Hash.ruby2_keywords_hash(a: 1)]
+  empty_kw_ary = [Hash.ruby2_keywords_hash({})]
+benchmark:
+  vm_send_cfunc: itself
+  vm_send_cfunc_splat: itself(*ary)
+  vm_send_cfunc_splat_kw_hash: equal?(*kw_ary)
+  vm_send_cfunc_splat_empty_kw_hash: itself(*empty_kw_ary)
+  vm_send_cfunc_splat_kw: equal?(*ary, **kw)
+  vm_send_cfunc_splat_empty_kw: itself(*ary, **empty_kw)
+loop_count: 20000000
diff --git a/benchmark/vm_simplereturn.yml b/benchmark/vm_simplereturn.yml
new file mode 100644
index 0000000000..c9829cff0b
--- /dev/null
+++ b/benchmark/vm_simplereturn.yml
@@ -0,0 +1,7 @@
+prelude: |
+  def m
+    return 1
+  end
+benchmark:
+  vm_simplereturn: m
+loop_count: 30000000
diff --git a/benchmark/vm_string_literal.yml b/benchmark/vm_string_literal.yml
new file mode 100644
index 0000000000..64439c7980
--- /dev/null
+++ b/benchmark/vm_string_literal.yml
@@ -0,0 +1,4 @@
+benchmark:
+  vm_string_literal: |
+    x = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+loop_count: 6000000
diff --git a/benchmark/vm_struct_big_aref_hi.yml b/benchmark/vm_struct_big_aref_hi.yml
new file mode 100644
index 0000000000..4cf78970cb
--- /dev/null
+++ b/benchmark/vm_struct_big_aref_hi.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
+  x = s.new
+benchmark:
+  vm_struct_big_aref_hi: |
+    x.z # x[25]
+loop_count: 6000000
diff --git a/benchmark/vm_struct_big_aref_lo.yml b/benchmark/vm_struct_big_aref_lo.yml
new file mode 100644
index 0000000000..c91af27fa5
--- /dev/null
+++ b/benchmark/vm_struct_big_aref_lo.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
+  x = s.new
+benchmark:
+  vm_struct_big_aref_lo: |
+    x.k # x[10]
+loop_count: 6000000
diff --git a/benchmark/vm_struct_big_aset.yml b/benchmark/vm_struct_big_aset.yml
new file mode 100644
index 0000000000..69550d14ea
--- /dev/null
+++ b/benchmark/vm_struct_big_aset.yml
@@ -0,0 +1,11 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_struct_big_aset: |
+    s = Struct.new(*('a'..'z').map { |x| x.to_sym })
+    x = s.new
+    i = 0
+    while i<6_000_000
+      i += 1
+      x.k = i # x[10] = i
+    end
+loop_count: 1
diff --git a/benchmark/vm_struct_big_href_hi.yml b/benchmark/vm_struct_big_href_hi.yml
new file mode 100644
index 0000000000..09b764dd13
--- /dev/null
+++ b/benchmark/vm_struct_big_href_hi.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
+  x = s.new
+benchmark:
+  vm_struct_big_href_hi: |
+    x[:z]
+loop_count: 6000000
diff --git a/benchmark/vm_struct_big_href_lo.yml b/benchmark/vm_struct_big_href_lo.yml
new file mode 100644
index 0000000000..d2f00b220f
--- /dev/null
+++ b/benchmark/vm_struct_big_href_lo.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(*('a'..'z').map { |x| x.to_sym })
+  x = s.new
+benchmark:
+  vm_struct_big_href_lo: |
+    x[:k]
+loop_count: 6000000
diff --git a/benchmark/vm_struct_big_hset.yml b/benchmark/vm_struct_big_hset.yml
new file mode 100644
index 0000000000..fc45cbee9c
--- /dev/null
+++ b/benchmark/vm_struct_big_hset.yml
@@ -0,0 +1,11 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_struct_big_hset: |
+    s = Struct.new(*('a'..'z').map { |x| x.to_sym })
+    x = s.new
+    i = 0
+    while i<6_000_000
+      i += 1
+      x[:k] = i
+    end
+loop_count: 1
diff --git a/benchmark/vm_struct_small_aref.yml b/benchmark/vm_struct_small_aref.yml
new file mode 100644
index 0000000000..5a83251d1e
--- /dev/null
+++ b/benchmark/vm_struct_small_aref.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(:a, :b, :c)
+  x = s.new
+benchmark:
+  vm_struct_small_aref: |
+    x.a
+loop_count: 6000000
diff --git a/benchmark/vm_struct_small_aset.yml b/benchmark/vm_struct_small_aset.yml
new file mode 100644
index 0000000000..74f435f126
--- /dev/null
+++ b/benchmark/vm_struct_small_aset.yml
@@ -0,0 +1,11 @@
+# loop_count is not utilized since `i` is involved in the script
+benchmark:
+  vm_struct_small_aset: |
+    s = Struct.new(:a, :b, :c)
+    x = s.new
+    i = 0
+    while i<6_000_000
+      i += 1
+      x.a = i
+    end
+loop_count: 1
diff --git a/benchmark/vm_struct_small_href.yml b/benchmark/vm_struct_small_href.yml
new file mode 100644
index 0000000000..6b7d7f39e7
--- /dev/null
+++ b/benchmark/vm_struct_small_href.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(:a, :b, :c)
+  x = s.new
+benchmark:
+  vm_struct_small_href: |
+    x[:a]
+loop_count: 6000000
diff --git a/benchmark/vm_struct_small_hset.yml b/benchmark/vm_struct_small_hset.yml
new file mode 100644
index 0000000000..5d43b150de
--- /dev/null
+++ b/benchmark/vm_struct_small_hset.yml
@@ -0,0 +1,7 @@
+prelude: |
+  s = Struct.new(:a, :b, :c)
+  x = s.new
+benchmark:
+  vm_struct_small_hset: |
+    x[:a] = 1
+loop_count: 6000000
diff --git a/benchmark/vm_super.yml b/benchmark/vm_super.yml
new file mode 100644
index 0000000000..0d1e965c6e
--- /dev/null
+++ b/benchmark/vm_super.yml
@@ -0,0 +1,17 @@
+prelude: |
+  class C
+    def m
+      1
+    end
+  end
+
+  class CC < C
+    def m
+      super()
+    end
+  end
+
+  obj = CC.new
+benchmark:
+  vm_super: obj.m
+loop_count: 6000000
diff --git a/benchmark/vm_super_splat_calls.yml b/benchmark/vm_super_splat_calls.yml
new file mode 100644
index 0000000000..795e44e4da
--- /dev/null
+++ b/benchmark/vm_super_splat_calls.yml
@@ -0,0 +1,25 @@
+prelude: |
+  @a = [1].freeze
+  @ea = [].freeze
+  @kw = {y: 1}.freeze
+  @b = lambda{}
+  extend(Module.new{def arg_splat(x=0, y: 0) end})
+  extend(Module.new{def arg_splat_block(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat_block(x=0, y: 0) end})
+  extend(Module.new{def splat_kw(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_block(x=0, y: 0) end})
+
+  extend(Module.new{def arg_splat; super(1, *@ea) end})
+  extend(Module.new{def arg_splat_block; super(1, *@ea, &@b) end})
+  extend(Module.new{def splat_kw_splat; super(*@a, **@kw) end})
+  extend(Module.new{def splat_kw_splat_block; super(*@a, **@kw, &@b) end})
+  extend(Module.new{def splat_kw; super(*@a, y: 1) end})
+  extend(Module.new{def splat_kw_block; super(*@a, y: 1, &@b) end})
+benchmark:
+  arg_splat: "arg_splat"
+  arg_splat_block: "arg_splat_block"
+  splat_kw_splat: "splat_kw_splat"
+  splat_kw_splat_block: "splat_kw_splat_block"
+  splat_kw: "splat_kw"
+  splat_kw_block: "splat_kw_block"
diff --git a/benchmark/vm_swap.yml b/benchmark/vm_swap.yml
new file mode 100644
index 0000000000..e824a65e0a
--- /dev/null
+++ b/benchmark/vm_swap.yml
@@ -0,0 +1,7 @@
+prelude: |
+  a = 1
+  b = 2
+benchmark:
+  vm_swap: |
+    a, b = b, a
+loop_count: 30000000
diff --git a/benchmark/vm_thread_condvar1.rb b/benchmark/vm_thread_condvar1.rb
index cf5706b23e..feed27c3ad 100644
--- a/benchmark/vm_thread_condvar1.rb
+++ b/benchmark/vm_thread_condvar1.rb
@@ -1,9 +1,9 @@
 # two threads, two mutex, two condvar ping-pong
 require 'thread'
-m1 = Mutex.new
-m2 = Mutex.new
-cv1 = ConditionVariable.new
-cv2 = ConditionVariable.new
+m1 = Thread::Mutex.new
+m2 = Thread::Mutex.new
+cv1 = Thread::ConditionVariable.new
+cv2 = Thread::ConditionVariable.new
 max = 100000
 i = 0
 wait = nil
diff --git a/benchmark/vm_thread_condvar2.rb b/benchmark/vm_thread_condvar2.rb
index 7c8dc19481..6590c4134b 100644
--- a/benchmark/vm_thread_condvar2.rb
+++ b/benchmark/vm_thread_condvar2.rb
@@ -1,16 +1,16 @@
 # many threads, one mutex, many condvars
 require 'thread'
-m = Mutex.new
-cv1 = ConditionVariable.new
-cv2 = ConditionVariable.new
+m = Thread::Mutex.new
+cv1 = Thread::ConditionVariable.new
+cv2 = Thread::ConditionVariable.new
 max = 1000
 n = 100
 waiting = 0
 scvs = []
 waiters = n.times.map do |i|
-  start_cv = ConditionVariable.new
+  start_cv = Thread::ConditionVariable.new
   scvs << start_cv
-  start_mtx = Mutex.new
+  start_mtx = Thread::Mutex.new
   start_mtx.synchronize do
     th = Thread.new(start_mtx, start_cv) do |sm, scv|
       m.synchronize do
diff --git a/benchmark/vm_unif1.yml b/benchmark/vm_unif1.yml
new file mode 100644
index 0000000000..04187bb0e2
--- /dev/null
+++ b/benchmark/vm_unif1.yml
@@ -0,0 +1,7 @@
+prelude: |
+  def m a, b
+  end
+benchmark:
+  vm_unif1: |
+    m 100, 200
+loop_count: 6000000
diff --git a/benchmark/vm_yield.yml b/benchmark/vm_yield.yml
new file mode 100644
index 0000000000..230be3d84f
--- /dev/null
+++ b/benchmark/vm_yield.yml
@@ -0,0 +1,13 @@
+# while loop cost is not removed due to benchmark_driver.gem's limitation
+benchmark:
+  vm_yield: |
+    def m
+      i = 0
+      while i<30_000_000
+        i += 1
+        yield
+      end
+    end
+
+    m{}
+loop_count: 1
diff --git a/benchmark/vm_zsuper.yml b/benchmark/vm_zsuper.yml
new file mode 100644
index 0000000000..bfb5837578
--- /dev/null
+++ b/benchmark/vm_zsuper.yml
@@ -0,0 +1,18 @@
+prelude: |
+  class C
+    def m a
+      1
+    end
+  end
+
+  class CC < C
+    def m a
+      super
+    end
+  end
+
+  obj = CC.new
+benchmark:
+  vm_zsuper: |
+    obj.m 10
+loop_count: 6000000
diff --git a/benchmark/vm_zsuper_splat_calls.yml b/benchmark/vm_zsuper_splat_calls.yml
new file mode 100644
index 0000000000..82dc22349d
--- /dev/null
+++ b/benchmark/vm_zsuper_splat_calls.yml
@@ -0,0 +1,28 @@
+prelude: |
+  a = [1].freeze
+  ea = [].freeze
+  kw = {y: 1}.freeze
+  b = lambda{}
+  extend(Module.new{def arg_splat(x=0, y: 0) end})
+  extend(Module.new{def arg_splat_block(x=0, y: 0) end})
+  extend(Module.new{def arg_splat_post(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat_block(x=0, y: 0) end})
+  extend(Module.new{def splat_kw(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_block(x=0, y: 0) end})
+
+  extend(Module.new{def arg_splat(x, *a) super end})
+  extend(Module.new{def arg_splat_block(x, *a, &b) super end})
+  extend(Module.new{def arg_splat_post(*a, x) super end})
+  extend(Module.new{def splat_kw_splat(*a, **kw) super end})
+  extend(Module.new{def splat_kw_splat_block(*a, **kw, &b) super end})
+  extend(Module.new{def splat_kw(*a, y: 1) super end})
+  extend(Module.new{def splat_kw_block(*a, y: 1, &b) super end})
+benchmark:
+  arg_splat: "arg_splat(1, *ea)"
+  arg_splat_block: "arg_splat_block(1, *ea, &b)"
+  arg_splat_post: "arg_splat_post(1, *ea, &b)"
+  splat_kw_splat: "splat_kw_splat(*a, **kw)"
+  splat_kw_splat_block: "splat_kw_splat_block(*a, **kw, &b)"
+  splat_kw: "splat_kw(*a, y: 1)"
+  splat_kw_block: "splat_kw_block(*a, y: 1, &b)"
diff --git a/bignum.c b/bignum.c
index f379b10489..28924b4eb9 100644
--- a/bignum.c
+++ b/bignum.c
@@ -9,34 +9,76 @@
 
 **********************************************************************/
 
-#include "internal.h"
-#include "ruby/thread.h"
-#include "ruby/util.h"
-#include "id.h"
+#include "ruby/internal/config.h"
+
+#include <ctype.h>
+#include <float.h>
+#include <math.h>
 
 #ifdef HAVE_STRINGS_H
-#include <strings.h>
+# include <strings.h>
 #endif
-#include <math.h>
-#include <float.h>
-#include <ctype.h>
+
 #ifdef HAVE_IEEEFP_H
-#include <ieeefp.h>
+# include <ieeefp.h>
 #endif
-#include "ruby_assert.h"
 
+#if !defined(USE_GMP)
 #if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
-#define USE_GMP
-#include <gmp.h>
+# define USE_GMP 1
+#else
+# define USE_GMP 0
+#endif
 #endif
 
-#define RB_BIGNUM_TYPE_P(x) RB_TYPE_P((x), T_BIGNUM)
+#include "id.h"
+#include "internal.h"
+#include "internal/bignum.h"
+#include "internal/complex.h"
+#include "internal/gc.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/sanitizers.h"
+#include "internal/variable.h"
+#include "internal/warnings.h"
+#include "ruby/thread.h"
+#include "ruby/util.h"
+#include "ruby_assert.h"
 
-#ifndef RUBY_INTEGER_UNIFICATION
-VALUE rb_cBignum;
+#if USE_GMP
+RBIMPL_WARNING_PUSH()
+# ifdef _MSC_VER
+RBIMPL_WARNING_IGNORED(4146) /* for mpn_neg() */
+# endif
+# include <gmp.h>
+RBIMPL_WARNING_POP()
 #endif
+
+static const bool debug_integer_pack = (
+#ifdef DEBUG_INTEGER_PACK
+    DEBUG_INTEGER_PACK+0
+#else
+    RUBY_DEBUG
+#endif
+    ) != 0;
+
 const char ruby_digitmap[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 
+/* Two-digit decimal lookup table.  Offset 2*n holds the ASCII pair for
+ * n in the range 0..99.  Used by both rb_fix2str in numeric.c and
+ * big2str_2bdigits below to emit two base-10 digits per iteration. */
+const char ruby_decimal_digit_pairs[201] =
+    "00010203040506070809"
+    "10111213141516171819"
+    "20212223242526272829"
+    "30313233343536373839"
+    "40414243444546474849"
+    "50515253545556575859"
+    "60616263646566676869"
+    "70717273747576777879"
+    "80818283848586878889"
+    "90919293949596979899";
+
 #ifndef SIZEOF_BDIGIT_DBL
 # if SIZEOF_INT*2 <= SIZEOF_LONG_LONG
 #  define SIZEOF_BDIGIT_DBL SIZEOF_LONG_LONG
@@ -52,7 +94,6 @@ STATIC_ASSERT(sizeof_bdigit_and_dbl, SIZEOF_BDIGIT*2 <= SIZEOF_BDIGIT_DBL);
 STATIC_ASSERT(bdigit_signedness, 0 < (BDIGIT)-1);
 STATIC_ASSERT(bdigit_dbl_signedness, 0 < (BDIGIT_DBL)-1);
 STATIC_ASSERT(bdigit_dbl_signed_signedness, 0 > (BDIGIT_DBL_SIGNED)-1);
-STATIC_ASSERT(rbignum_embed_len_max, BIGNUM_EMBED_LEN_MAX <= (BIGNUM_EMBED_LEN_MASK >> BIGNUM_EMBED_LEN_SHIFT));
 
 #if SIZEOF_BDIGIT < SIZEOF_LONG
 STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_LONG % SIZEOF_BDIGIT == 0);
@@ -65,7 +106,7 @@ STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_BDIGIT % SIZEOF_LONG == 0);
 #else
 #   define HOST_BIGENDIAN_P 0
 #endif
-/* (!LSHIFTABLE(d, n) ? 0 : (n)) is same as n but suppress a warning, C4293, by Visual Studio.  */
+/* (!LSHIFTABLE(d, n) ? 0 : (n)) is the same as n but suppress a warning, C4293, by Visual Studio.  */
 #define LSHIFTABLE(d, n) ((n) < sizeof(d) * CHAR_BIT)
 #define LSHIFTX(d, n) (!LSHIFTABLE(d, n) ? 0 : ((d) << (!LSHIFTABLE(d, n) ? 0 : (n))))
 #define CLEAR_LOWBITS(d, numbits) ((d) & LSHIFTX(~((d)*0), (numbits)))
@@ -92,8 +133,8 @@ STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_BDIGIT % SIZEOF_LONG == 0);
 #endif
 
 #define BIGZEROP(x) (BIGNUM_LEN(x) == 0 || \
-		     (BDIGITS(x)[0] == 0 && \
-		      (BIGNUM_LEN(x) == 1 || bigzero_p(x))))
+                     (BDIGITS(x)[0] == 0 && \
+                      (BIGNUM_LEN(x) == 1 || bigzero_p(x))))
 #define BIGSIZE(x) (BIGNUM_LEN(x) == 0 ? (size_t)0 : \
     BDIGITS(x)[BIGNUM_LEN(x)-1] ? \
         (size_t)(BIGNUM_LEN(x)*SIZEOF_BDIGIT - nlz(BDIGITS(x)[BIGNUM_LEN(x)-1])/CHAR_BIT) : \
@@ -138,7 +179,7 @@ STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_BDIGIT % SIZEOF_LONG == 0);
 #define GMP_DIV_DIGITS 20
 #define GMP_BIG2STR_DIGITS 20
 #define GMP_STR2BIG_DIGITS 20
-#ifdef USE_GMP
+#if USE_GMP
 # define NAIVE_MUL_DIGITS GMP_MUL_DIGITS
 #else
 # define NAIVE_MUL_DIGITS KARATSUBA_MUL_DIGITS
@@ -149,15 +190,11 @@ typedef void (mulfunc_t)(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, c
 static mulfunc_t bary_mul_toom3_start;
 static mulfunc_t bary_mul_karatsuba_start;
 static BDIGIT bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y);
-static void bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn);
 
-static VALUE bigmul0(VALUE x, VALUE y);
-static void bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn);
 static VALUE bignew_1(VALUE klass, size_t len, int sign);
 static inline VALUE bigtrunc(VALUE x);
 
 static VALUE bigsq(VALUE x);
-static void bigdivmod(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp);
 static inline VALUE power_cache_get_power(int base, int power_level, size_t *numdigits_ret);
 
 #if SIZEOF_BDIGIT <= SIZEOF_INT
@@ -332,7 +369,7 @@ maxpow_in_bdigit_dbl(int base, int *exp_ret)
     BDIGIT_DBL maxpow;
     int exponent;
 
-    assert(2 <= base && base <= 36);
+    RUBY_ASSERT(2 <= base && base <= 36);
 
     {
 #if SIZEOF_BDIGIT_DBL == 2
@@ -364,7 +401,7 @@ maxpow_in_bdigit_dbl(int base, int *exp_ret)
 static inline BDIGIT_DBL
 bary2bdigitdbl(const BDIGIT *ds, size_t n)
 {
-    assert(n <= 2);
+    RUBY_ASSERT(n <= 2);
 
     if (n == 2)
         return ds[0] | BIGUP(ds[1]);
@@ -376,7 +413,7 @@ bary2bdigitdbl(const BDIGIT *ds, size_t n)
 static inline void
 bdigitdbl2bary(BDIGIT *ds, size_t n, BDIGIT_DBL num)
 {
-    assert(n == 2);
+    RUBY_ASSERT(n == 2);
 
     ds[0] = BIGLO(num);
     ds[1] = (BDIGIT)BIGDN(num);
@@ -407,12 +444,12 @@ bary_small_lshift(BDIGIT *zds, const BDIGIT *xds, size_t n, int shift)
 {
     size_t i;
     BDIGIT_DBL num = 0;
-    assert(0 <= shift && shift < BITSPERDIG);
+    RUBY_ASSERT(0 <= shift && shift < BITSPERDIG);
 
     for (i=0; i<n; i++) {
-	num = num | (BDIGIT_DBL)*xds++ << shift;
-	*zds++ = BIGLO(num);
-	num = BIGDN(num);
+        num = num | (BDIGIT_DBL)*xds++ << shift;
+        *zds++ = BIGLO(num);
+        num = BIGDN(num);
     }
     return BIGLO(num);
 }
@@ -423,14 +460,14 @@ bary_small_rshift(BDIGIT *zds, const BDIGIT *xds, size_t n, int shift, BDIGIT hi
     size_t i;
     BDIGIT_DBL num = 0;
 
-    assert(0 <= shift && shift < BITSPERDIG);
+    RUBY_ASSERT(0 <= shift && shift < BITSPERDIG);
 
     num = BIGUP(higher_bdigit);
     for (i = 0; i < n; i++) {
         BDIGIT x = xds[n - i - 1];
-	num = (num | x) >> shift;
+        num = (num | x) >> shift;
         zds[n - i - 1] = BIGLO(num);
-	num = BIGUP(x);
+        num = BIGUP(x);
     }
 }
 
@@ -440,7 +477,7 @@ bary_zero_p(const BDIGIT *xds, size_t xn)
     if (xn == 0)
         return 1;
     do {
-	if (xds[--xn]) return 0;
+        if (xds[--xn]) return 0;
     } while (xn);
     return 1;
 }
@@ -457,7 +494,6 @@ static int
 bary_2comp(BDIGIT *ds, size_t n)
 {
     size_t i;
-    i = 0;
     for (i = 0; i < n; i++) {
         if (ds[i] != 0) {
             goto non_zero;
@@ -969,7 +1005,7 @@ integer_unpack_num_bdigits_small(size_t numwords, size_t wordsize, size_t nails,
 {
     /* nlp_bits stands for number of leading padding bits */
     size_t num_bits = (wordsize * CHAR_BIT - nails) * numwords;
-    size_t num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG;
+    size_t num_bdigits = roomof(num_bits, BITSPERDIG);
     *nlp_bits_ret = (int)(num_bdigits * BITSPERDIG - num_bits);
     return num_bdigits;
 }
@@ -979,7 +1015,7 @@ integer_unpack_num_bdigits_generic(size_t numwords, size_t wordsize, size_t nail
 {
     /* BITSPERDIG = SIZEOF_BDIGIT * CHAR_BIT */
     /* num_bits = (wordsize * CHAR_BIT - nails) * numwords */
-    /* num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG */
+    /* num_bdigits = roomof(num_bits, BITSPERDIG) */
 
     /* num_bits = CHAR_BIT * (wordsize * numwords) - nails * numwords = CHAR_BIT * num_bytes1 - nails * numwords */
     size_t num_bytes1 = wordsize * numwords;
@@ -1041,14 +1077,13 @@ integer_unpack_num_bdigits(size_t numwords, size_t wordsize, size_t nails, int *
 
     if (numwords <= (SIZE_MAX - (BITSPERDIG-1)) / CHAR_BIT / wordsize) {
         num_bdigits = integer_unpack_num_bdigits_small(numwords, wordsize, nails, nlp_bits_ret);
-#ifdef DEBUG_INTEGER_PACK
-        {
+        if (debug_integer_pack) {
             int nlp_bits1;
             size_t num_bdigits1 = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, &nlp_bits1);
-            assert(num_bdigits == num_bdigits1);
-            assert(*nlp_bits_ret == nlp_bits1);
+            RUBY_ASSERT(num_bdigits == num_bdigits1);
+            RUBY_ASSERT(*nlp_bits_ret == nlp_bits1);
+            (void)num_bdigits1;
         }
-#endif
     }
     else {
         num_bdigits = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, nlp_bits_ret);
@@ -1256,7 +1291,7 @@ bary_unpack_internal(BDIGIT *bdigits, size_t num_bdigits, const void *words, siz
         }
         if (dd)
             *dp++ = (BDIGIT)dd;
-        assert(dp <= de);
+        RUBY_ASSERT(dp <= de);
         while (dp < de)
             *dp++ = 0;
 #undef PUSH_BITS
@@ -1315,7 +1350,7 @@ bary_unpack(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwo
 
     num_bdigits0 = integer_unpack_num_bdigits(numwords, wordsize, nails, &nlp_bits);
 
-    assert(num_bdigits0 <= num_bdigits);
+    RUBY_ASSERT(num_bdigits0 <= num_bdigits);
 
     sign = bary_unpack_internal(bdigits, num_bdigits0, words, numwords, wordsize, nails, flags, nlp_bits);
 
@@ -1334,16 +1369,16 @@ bary_subb(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     size_t i;
     size_t sn;
 
-    assert(xn <= zn);
-    assert(yn <= zn);
+    RUBY_ASSERT(xn <= zn);
+    RUBY_ASSERT(yn <= zn);
 
     sn = xn < yn ? xn : yn;
 
     num = borrow ? -1 : 0;
     for (i = 0; i < sn; i++) {
-	num += (BDIGIT_DBL_SIGNED)xds[i] - yds[i];
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        num += (BDIGIT_DBL_SIGNED)xds[i] - yds[i];
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
     if (yn <= xn) {
         for (; i < xn; i++) {
@@ -1362,7 +1397,7 @@ bary_subb(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     }
     if (num == 0) goto num_is_zero;
     for (; i < zn; i++) {
-	zds[i] = BDIGMAX;
+        zds[i] = BDIGMAX;
     }
     return 1;
 
@@ -1370,10 +1405,10 @@ bary_subb(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     if (xds == zds && xn == zn)
         return 0;
     for (; i < xn; i++) {
-	zds[i] = xds[i];
+        zds[i] = xds[i];
     }
     for (; i < zn; i++) {
-	zds[i] = 0;
+        zds[i] = 0;
     }
     return 0;
 }
@@ -1396,31 +1431,31 @@ bary_addc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     BDIGIT_DBL num;
     size_t i;
 
-    assert(xn <= zn);
-    assert(yn <= zn);
+    RUBY_ASSERT(xn <= zn);
+    RUBY_ASSERT(yn <= zn);
 
     if (xn > yn) {
-	const BDIGIT *tds;
-	tds = xds; xds = yds; yds = tds;
-	i = xn; xn = yn; yn = i;
+        const BDIGIT *tds;
+        tds = xds; xds = yds; yds = tds;
+        i = xn; xn = yn; yn = i;
     }
 
     num = carry ? 1 : 0;
     for (i = 0; i < xn; i++) {
-	num += (BDIGIT_DBL)xds[i] + yds[i];
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        num += (BDIGIT_DBL)xds[i] + yds[i];
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
     for (; i < yn; i++) {
         if (num == 0) goto num_is_zero;
-	num += yds[i];
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        num += yds[i];
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
     for (; i < zn; i++) {
         if (num == 0) goto num_is_zero;
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
     return num != 0;
 
@@ -1428,10 +1463,10 @@ bary_addc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     if (yds == zds && yn == zn)
         return 0;
     for (; i < yn; i++) {
-	zds[i] = yds[i];
+        zds[i] = yds[i];
     }
     for (; i < zn; i++) {
-	zds[i] = 0;
+        zds[i] = 0;
     }
     return 0;
 }
@@ -1461,7 +1496,7 @@ bary_mul_single(BDIGIT *zds, size_t zn, BDIGIT x, BDIGIT y)
 {
     BDIGIT_DBL n;
 
-    assert(2 <= zn);
+    RUBY_ASSERT(2 <= zn);
 
     n = (BDIGIT_DBL)x * y;
     bdigitdbl2bary(zds, 2, n);
@@ -1475,7 +1510,7 @@ bary_muladd_1xN(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
     BDIGIT_DBL dd;
     size_t j;
 
-    assert(zn > yn);
+    RUBY_ASSERT(zn > yn);
 
     if (x == 0)
         return 0;
@@ -1510,7 +1545,7 @@ bigdivrem_mulsub(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
     BDIGIT_DBL t2;
     BDIGIT_DBL_SIGNED num;
 
-    assert(zn == yn + 1);
+    RUBY_ASSERT(zn == yn + 1);
 
     num = 0;
     t2 = 0;
@@ -1535,7 +1570,7 @@ bary_mulsub_1xN(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
 {
     BDIGIT_DBL_SIGNED num;
 
-    assert(zn == yn + 1);
+    RUBY_ASSERT(zn == yn + 1);
 
     num = bigdivrem_mulsub(zds, zn, x, yds, yn);
     zds[yn] = BIGLO(num);
@@ -1549,7 +1584,7 @@ bary_mul_normal(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIG
 {
     size_t i;
 
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     BDIGITS_ZERO(zds, zn);
     for (i = 0; i < xn; i++) {
@@ -1570,7 +1605,7 @@ rb_big_mul_normal(VALUE x, VALUE y)
 
 /* efficient squaring (2 times faster than normal multiplication)
  * ref: Handbook of Applied Cryptography, Algorithm 14.16
- *      http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf
+ *      https://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf
  */
 static void
 bary_sq_fast(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn)
@@ -1580,7 +1615,7 @@ bary_sq_fast(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn)
     BDIGIT vl;
     int vh;
 
-    assert(xn * 2 <= zn);
+    RUBY_ASSERT(xn * 2 <= zn);
 
     BDIGITS_ZERO(zds, zn);
 
@@ -1588,30 +1623,30 @@ bary_sq_fast(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn)
         return;
 
     for (i = 0; i < xn-1; i++) {
-	v = (BDIGIT_DBL)xds[i];
-	if (!v)
+        v = (BDIGIT_DBL)xds[i];
+        if (!v)
             continue;
-	c = (BDIGIT_DBL)zds[i + i] + v * v;
-	zds[i + i] = BIGLO(c);
-	c = BIGDN(c);
-	v *= 2;
+        c = (BDIGIT_DBL)zds[i + i] + v * v;
+        zds[i + i] = BIGLO(c);
+        c = BIGDN(c);
+        v *= 2;
         vl = BIGLO(v);
         vh = (int)BIGDN(v);
-	for (j = i + 1; j < xn; j++) {
-	    w = (BDIGIT_DBL)xds[j];
-	    c += (BDIGIT_DBL)zds[i + j] + vl * w;
-	    zds[i + j] = BIGLO(c);
-	    c = BIGDN(c);
-	    if (vh)
+        for (j = i + 1; j < xn; j++) {
+            w = (BDIGIT_DBL)xds[j];
+            c += (BDIGIT_DBL)zds[i + j] + vl * w;
+            zds[i + j] = BIGLO(c);
+            c = BIGDN(c);
+            if (vh)
                 c += w;
-	}
-	if (c) {
-	    c += (BDIGIT_DBL)zds[i + xn];
-	    zds[i + xn] = BIGLO(c);
-	    c = BIGDN(c);
+        }
+        if (c) {
+            c += (BDIGIT_DBL)zds[i + xn];
+            zds[i + xn] = BIGLO(c);
+            c = BIGDN(c);
             if (c)
                 zds[i + xn + 1] += (BDIGIT)c;
-	}
+        }
     }
 
     /* i == xn-1 */
@@ -1636,28 +1671,48 @@ rb_big_sq_fast(VALUE x)
     return z;
 }
 
+static inline size_t
+max_size(size_t a, size_t b)
+{
+    return (a > b ? a : b);
+}
+
 /* balancing multiplication by slicing larger argument */
 static void
-bary_mul_balance_with_mulfunc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn, mulfunc_t *mulfunc)
+bary_mul_balance_with_mulfunc(BDIGIT *const zds, const size_t zn,
+                              const BDIGIT *const xds, const size_t xn,
+                              const BDIGIT *const yds, const size_t yn,
+                              BDIGIT *wds, size_t wn, mulfunc_t *const mulfunc)
 {
     VALUE work = 0;
-    size_t yn0 = yn;
-    size_t r, n;
+    size_t n;
 
-    assert(xn + yn <= zn);
-    assert(xn <= yn);
-    assert(!KARATSUBA_BALANCED(xn, yn) || !TOOM3_BALANCED(xn, yn));
+    RUBY_ASSERT(xn + yn <= zn);
+    RUBY_ASSERT(xn <= yn);
+    RUBY_ASSERT(!KARATSUBA_BALANCED(xn, yn) || !TOOM3_BALANCED(xn, yn));
 
     BDIGITS_ZERO(zds, xn);
 
+    if (wn < xn) {
+        /* The condition when a new buffer is needed:
+         * 1. (2(xn+r) > zn-(yn-r)) => (2xn+r > zn-yn), at the last
+         *    iteration (or r == 0)
+         * 2. (2(xn+xn) > zn-(yn-r-xn)) => (3xn-r > zn-yn), at the
+         *    previous iteration.
+         */
+        const size_t r = yn % xn;
+        if (2*xn + yn + max_size(xn-r, r) > zn) {
+            wn = xn;
+            wds = ALLOCV_N(BDIGIT, work, wn);
+        }
+    }
+
     n = 0;
-    while (yn > 0) {
-        BDIGIT *tds;
-        size_t tn;
-	r = xn > yn ? yn : xn;
-        tn = xn + r;
+    while (yn > n) {
+        const size_t r = (xn > (yn - n) ? (yn - n) : xn);
+        const size_t tn = (xn + r);
         if (2 * (xn + r) <= zn - n) {
-            tds = zds + n + xn + r;
+            BDIGIT *const tds = zds + n + xn + r;
             mulfunc(tds, tn, xds, xn, yds + n, r, wds, wn);
             BDIGITS_ZERO(zds + n + xn, r);
             bary_add(zds + n, tn,
@@ -1665,21 +1720,25 @@ bary_mul_balance_with_mulfunc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t
                      tds, tn);
         }
         else {
+            BDIGIT *const tds = zds + n;
             if (wn < xn) {
+                /* xn is invariant, only once here */
+#if 0
                 wn = xn;
                 wds = ALLOCV_N(BDIGIT, work, wn);
+#else
+                rb_bug("wds is not enough: %" PRIdSIZE " for %" PRIdSIZE, wn, xn);
+#endif
             }
-            tds = zds + n;
             MEMCPY(wds, zds + n, BDIGIT, xn);
             mulfunc(tds, tn, xds, xn, yds + n, r, wds+xn, wn-xn);
             bary_add(zds + n, tn,
                      zds + n, tn,
                      wds, xn);
         }
-	yn -= r;
-	n += r;
+        n += r;
     }
-    BDIGITS_ZERO(zds+xn+yn0, zn - (xn+yn0));
+    BDIGITS_ZERO(zds+xn+yn, zn - (xn+yn));
 
     if (work)
         ALLOCV_END(work);
@@ -1712,9 +1771,9 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const B
     const BDIGIT *xds0, *xds1, *yds0, *yds1;
     BDIGIT *zds0, *zds1, *zds2, *zds3;
 
-    assert(xn + yn <= zn);
-    assert(xn <= yn);
-    assert(yn < 2 * xn);
+    RUBY_ASSERT(xn + yn <= zn);
+    RUBY_ASSERT(xn <= yn);
+    RUBY_ASSERT(yn < 2 * xn);
 
     sq = xds == yds && xn == yn;
 
@@ -1729,7 +1788,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const B
 
     n = yn / 2;
 
-    assert(n < xn);
+    RUBY_ASSERT(n < xn);
 
     if (wn < n) {
         /* This function itself needs only n BDIGITs for work area.
@@ -1850,7 +1909,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const B
         for (x = 0, i = xn-1; 0 <= i; i--) { x <<= SIZEOF_BDIGIT*CHAR_BIT; x |= xds[i]; }
         for (y = 0, i = yn-1; 0 <= i; i--) { y <<= SIZEOF_BDIGIT*CHAR_BIT; y |= yds[i]; }
         for (z = 0, i = zn-1; 0 <= i; i--) { z <<= SIZEOF_BDIGIT*CHAR_BIT; z |= zds[i]; }
-        assert(z == x * y);
+        RUBY_ASSERT(z == x * y);
     }
     */
 
@@ -1918,11 +1977,11 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
 
     int sq = xds == yds && xn == yn;
 
-    assert(xn <= yn);  /* assume y >= x */
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn <= yn);  /* assume y >= x */
+    RUBY_ASSERT(xn + yn <= zn);
 
     n = (yn + 2) / 3;
-    assert(2*n < xn);
+    RUBY_ASSERT(2*n < xn);
 
     wnc = 0;
 
@@ -1996,7 +2055,7 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
     }
 
     /*
-     * ref. http://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication
+     * ref. https://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication
      *
      * x(b) = x0 * b^0 + x1 * b^1 + x2 * b^2
      * y(b) = y0 * b^0 + y1 * b^1 + y2 * b^2
@@ -2069,21 +2128,21 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
         v3n = u3n; v3ds = u3ds; v3p = u3p;
     }
     else {
-	/* v1 <- y0 + y2 */
+        /* v1 <- y0 + y2 */
         bary_add(v1ds, v1n, y0ds, y0n, y2ds, y2n);
         v1p = 1;
 
-	/* y(-1) : v2 <- v1 - y1 = y0 - y1 + y2 */
+        /* y(-1) : v2 <- v1 - y1 = y0 - y1 + y2 */
         v2p = 1;
         if (bary_sub(v2ds, v2n, v1ds, v1n, y1ds, y1n)) {
             bary_2comp(v2ds, v2n);
             v2p = 0;
         }
 
-	/* y(1) : v1 <- v1 + y1 = y0 + y1 + y2 */
+        /* y(1) : v1 <- v1 + y1 = y0 + y1 + y2 */
         bary_add(v1ds, v1n, v1ds, v1n, y1ds, y1n);
 
-	/* y(-2) : v3 <- 2 * (v2 + y2) - y0 = y0 - 2 * (y1 - 2 * y2) */
+        /* y(-2) : v3 <- 2 * (v2 + y2) - y0 = y0 - 2 * (y1 - 2 * y2) */
         v3p = 1;
         if (v2p) {
             bary_add(v3ds, v3n, v2ds, v2n, y2ds, y2n);
@@ -2109,19 +2168,19 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
     /* z(1) : t1 <- u1 * v1 */
     bary_mul_toom3_start(t1ds, t1n, u1ds, u1n, v1ds, v1n, wds, wn);
     t1p = u1p == v1p;
-    assert(t1ds[t1n-1] == 0);
+    RUBY_ASSERT(t1ds[t1n-1] == 0);
     t1n--;
 
     /* z(-1) : t2 <- u2 * v2 */
     bary_mul_toom3_start(t2ds, t2n, u2ds, u2n, v2ds, v2n, wds, wn);
     t2p = u2p == v2p;
-    assert(t2ds[t2n-1] == 0);
+    RUBY_ASSERT(t2ds[t2n-1] == 0);
     t2n--;
 
     /* z(-2) : t3 <- u3 * v3 */
     bary_mul_toom3_start(t3ds, t3n, u3ds, u3n, v3ds, v3n, wds, wn);
     t3p = u3p == v3p;
-    assert(t3ds[t3n-1] == 0);
+    RUBY_ASSERT(t3ds[t3n-1] == 0);
     t3n--;
 
     /* z(inf) : t4 <- x2 * y2 */
@@ -2276,28 +2335,41 @@ rb_big_mul_toom3(VALUE x, VALUE y)
     return z;
 }
 
-#ifdef USE_GMP
+#if USE_GMP
+static inline void
+bdigits_to_mpz(mpz_t mp, const BDIGIT *digits, size_t len)
+{
+    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
+    mpz_import(mp, len, -1, sizeof(BDIGIT), 0, nails, digits);
+}
+
+static inline void
+bdigits_from_mpz(mpz_t mp, BDIGIT *digits, size_t *len)
+{
+    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
+    mpz_export(digits, len, -1, sizeof(BDIGIT), 0, nails, mp);
+}
+
 static void
 bary_mul_gmp(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
     mpz_t x, y, z;
     size_t count;
 
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     mpz_init(x);
     mpz_init(y);
     mpz_init(z);
-    mpz_import(x, xn, -1, sizeof(BDIGIT), 0, nails, xds);
+    bdigits_to_mpz(x, xds, xn);
     if (xds == yds && xn == yn) {
         mpz_mul(z, x, x);
     }
     else {
-        mpz_import(y, yn, -1, sizeof(BDIGIT), 0, nails, yds);
+        bdigits_to_mpz(y, yds, yn);
         mpz_mul(z, x, y);
     }
-    mpz_export(zds, &count, -1, sizeof(BDIGIT), 0, nails, z);
+    bdigits_from_mpz(z, zds, &count);
     BDIGITS_ZERO(zds+count, zn-count);
     mpz_clear(x);
     mpz_clear(y);
@@ -2319,7 +2391,7 @@ rb_big_mul_gmp(VALUE x, VALUE y)
 static void
 bary_short_mul(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     if (xn == 1 && yn == 1) {
         bary_mul_single(zds, zn, xds[0], yds[0]);
@@ -2336,9 +2408,9 @@ bary_sparse_p(const BDIGIT *ds, size_t n)
 {
     long c = 0;
 
-    if (          ds[rb_genrand_ulong_limited(n / 2) + n / 4]) c++;
-    if (c <= 1 && ds[rb_genrand_ulong_limited(n / 2) + n / 4]) c++;
-    if (c <= 1 && ds[rb_genrand_ulong_limited(n / 2) + n / 4]) c++;
+    if (          ds[2 * n / 5]) c++;
+    if (c <= 1 && ds[    n / 2]) c++;
+    if (c <= 1 && ds[3 * n / 5]) c++;
 
     return (c <= 1) ? 1 : 0;
 }
@@ -2355,7 +2427,7 @@ bary_mul_precheck(BDIGIT **zdsp, size_t *znp, const BDIGIT **xdsp, size_t *xnp,
     const BDIGIT *yds = *ydsp;
     size_t yn = *ynp;
 
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     nlsz = 0;
 
@@ -2401,10 +2473,10 @@ bary_mul_precheck(BDIGIT **zdsp, size_t *znp, const BDIGIT **xdsp, size_t *xnp,
     if (xn > yn) {
         const BDIGIT *tds;
         size_t tn;
-	tds = xds; xds = yds; yds = tds;
-	tn = xn; xn = yn; yn = tn;
+        tds = xds; xds = yds; yds = tds;
+        tn = xn; xn = yn; yn = tn;
     }
-    assert(xn <= yn);
+    RUBY_ASSERT(xn <= yn);
 
     if (xn <= 1) {
         if (xn == 0) {
@@ -2446,12 +2518,7 @@ bary_mul_karatsuba_branch(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn,
 {
     /* normal multiplication when x is small */
     if (xn < KARATSUBA_MUL_DIGITS) {
-      normal:
-        if (xds == yds && xn == yn)
-            bary_sq_fast(zds, zn, xds, xn);
-        else
-            bary_short_mul(zds, zn, xds, xn, yds, yn);
-        return;
+        goto normal;
     }
 
     /* normal multiplication when x or y is a sparse bignum */
@@ -2469,6 +2536,15 @@ bary_mul_karatsuba_branch(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn,
 
     /* multiplication by karatsuba method */
     bary_mul_karatsuba(zds, zn, xds, xn, yds, yn, wds, wn);
+    return;
+
+  normal:
+    if (xds == yds && xn == yn) {
+        bary_sq_fast(zds, zn, xds, xn);
+    }
+    else {
+        bary_short_mul(zds, zn, xds, xn, yds, yn);
+    }
 }
 
 static void
@@ -2524,7 +2600,7 @@ bary_mul(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds
         }
     }
 
-#ifdef USE_GMP
+#if USE_GMP
     bary_mul_gmp(zds, zn, xds, xn, yds, yn);
 #else
     bary_mul_toom3_start(zds, zn, xds, xn, yds, yn, NULL, 0);
@@ -2548,26 +2624,26 @@ bigdivrem1(void *ptr)
     BDIGIT q;
 
     do {
-	if (bds->stop) {
-	    bds->zn = zn;
-	    return 0;
+        if (bds->stop) {
+            bds->zn = zn;
+            return 0;
         }
-	if (zds[zn-1] == yds[yn-1]) q = BDIGMAX;
-	else q = (BDIGIT)((BIGUP(zds[zn-1]) + zds[zn-2])/yds[yn-1]);
-	if (q) {
+        if (zds[zn-1] == yds[yn-1]) q = BDIGMAX;
+        else q = (BDIGIT)((BIGUP(zds[zn-1]) + zds[zn-2])/yds[yn-1]);
+        if (q) {
             num = bigdivrem_mulsub(zds+zn-(yn+1), yn+1,
                                    q,
                                    yds, yn);
-	    while (num) { /* "add back" required */
-		q--;
+            while (num) { /* "add back" required */
+                q--;
                 num = bary_add(zds+zn-(yn+1), yn,
                                zds+zn-(yn+1), yn,
                                yds, yn);
                 num--;
-	    }
-	}
+            }
+        }
         zn--;
-	zds[zn] = q;
+        zds[zn] = q;
     } while (zn > yn);
     return 0;
 }
@@ -2583,8 +2659,8 @@ rb_big_stop(void *ptr)
 static BDIGIT
 bigdivrem_single1(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT x_higher_bdigit, BDIGIT y)
 {
-    assert(0 < xn);
-    assert(x_higher_bdigit < y);
+    RUBY_ASSERT(0 < xn);
+    RUBY_ASSERT(x_higher_bdigit < y);
     if (POW2_P(y)) {
         BDIGIT r;
         r = xds[0] & (y-1);
@@ -2616,9 +2692,9 @@ bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn)
     struct big_div_struct bds;
     size_t ynzero;
 
-    assert(yn < zn);
-    assert(BDIGIT_MSB(yds[yn-1]));
-    assert(zds[zn-1] < yds[yn-1]);
+    RUBY_ASSERT(yn < zn);
+    RUBY_ASSERT(BDIGIT_MSB(yds[yn-1]));
+    RUBY_ASSERT(zds[zn-1] < yds[yn-1]);
 
     for (ynzero = 0; !yds[ynzero]; ynzero++);
 
@@ -2636,16 +2712,16 @@ bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn)
     bds.zn = zn - ynzero;
     if (bds.zn > 10000 || bds.yn > 10000) {
       retry:
-	bds.stop = Qfalse;
-        rb_nogvl(bigdivrem1, &bds, rb_big_stop, &bds, RB_NOGVL_UBF_ASYNC_SAFE);
+        bds.stop = Qfalse;
+        rb_nogvl(bigdivrem1, &bds, rb_big_stop, &bds, RB_NOGVL_UBF_ASYNC_SAFE | RB_NOGVL_OFFLOAD_SAFE);
 
-	if (bds.stop == Qtrue) {
-	    /* execute trap handler, but exception was not raised. */
-	    goto retry;
-	}
+        if (bds.stop == Qtrue) {
+            /* execute trap handler, but exception was not raised. */
+            goto retry;
+        }
     }
     else {
-	bigdivrem1(&bds);
+        bigdivrem1(&bds);
     }
 }
 
@@ -2657,9 +2733,9 @@ bary_divmod_normal(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT
     size_t zn;
     VALUE tmpyz = 0;
 
-    assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
-    assert(qds ? (xn - yn + 1) <= qn : 1);
-    assert(rds ? yn <= rn : 1);
+    RUBY_ASSERT(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
+    RUBY_ASSERT(qds ? (xn - yn + 1) <= qn : 1);
+    RUBY_ASSERT(rds ? yn <= rn : 1);
 
     zn = xn + BIGDIVREM_EXTRA_WORDS;
 
@@ -2744,26 +2820,25 @@ rb_big_divrem_normal(VALUE x, VALUE y)
     return rb_assoc_new(q, r);
 }
 
-#ifdef USE_GMP
+#if USE_GMP
 static void
 bary_divmod_gmp(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
     mpz_t x, y, q, r;
     size_t count;
 
-    assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
-    assert(qds ? (xn - yn + 1) <= qn : 1);
-    assert(rds ? yn <= rn : 1);
-    assert(qds || rds);
+    RUBY_ASSERT(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
+    RUBY_ASSERT(qds ? (xn - yn + 1) <= qn : 1);
+    RUBY_ASSERT(rds ? yn <= rn : 1);
+    RUBY_ASSERT(qds || rds);
 
     mpz_init(x);
     mpz_init(y);
     if (qds) mpz_init(q);
     if (rds) mpz_init(r);
 
-    mpz_import(x, xn, -1, sizeof(BDIGIT), 0, nails, xds);
-    mpz_import(y, yn, -1, sizeof(BDIGIT), 0, nails, yds);
+    bdigits_to_mpz(x, xds, xn);
+    bdigits_to_mpz(y, yds, yn);
 
     if (!rds) {
         mpz_fdiv_q(q, x, y);
@@ -2779,13 +2854,13 @@ bary_divmod_gmp(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xd
     mpz_clear(y);
 
     if (qds) {
-        mpz_export(qds, &count, -1, sizeof(BDIGIT), 0, nails, q);
+        bdigits_from_mpz(q, qds, &count);
         BDIGITS_ZERO(qds+count, qn-count);
         mpz_clear(q);
     }
 
     if (rds) {
-        mpz_export(rds, &count, -1, sizeof(BDIGIT), 0, nails, r);
+        bdigits_from_mpz(r, rds, &count);
         BDIGITS_ZERO(rds+count, rn-count);
         mpz_clear(r);
     }
@@ -2829,7 +2904,7 @@ rb_big_divrem_gmp(VALUE x, VALUE y)
 static void
 bary_divmod_branch(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-#ifdef USE_GMP
+#if USE_GMP
     if (GMP_DIV_DIGITS < xn) {
         bary_divmod_gmp(qds, qn, rds, rn, xds, xn, yds, yn);
         return;
@@ -2841,8 +2916,8 @@ bary_divmod_branch(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT
 static void
 bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-    assert(xn <= qn);
-    assert(yn <= rn);
+    RUBY_ASSERT(xn <= qn);
+    RUBY_ASSERT(yn <= rn);
 
     BARY_TRUNC(yds, yn);
     if (yn == 0)
@@ -2883,32 +2958,6 @@ bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, s
     }
 }
 
-
-#define BIGNUM_DEBUG 0
-#if BIGNUM_DEBUG
-#define ON_DEBUG(x) do { x; } while (0)
-static void
-dump_bignum(VALUE x)
-{
-    long i;
-    printf("%c0x0", BIGNUM_SIGN(x) ? '+' : '-');
-    for (i = BIGNUM_LEN(x); i--; ) {
-        printf("_%0*"PRIxBDIGIT, SIZEOF_BDIGIT*2, BDIGITS(x)[i]);
-    }
-    printf(", len=%"PRIuSIZE, BIGNUM_LEN(x));
-    puts("");
-}
-
-static VALUE
-rb_big_dump(VALUE x)
-{
-    dump_bignum(x);
-    return x;
-}
-#else
-#define ON_DEBUG(x)
-#endif
-
 static int
 bigzero_p(VALUE x)
 {
@@ -2925,7 +2974,7 @@ int
 rb_cmpint(VALUE val, VALUE a, VALUE b)
 {
     if (NIL_P(val)) {
-	rb_cmperr(a, b);
+        rb_cmperr_reason(a, b, "comparator returned nil");
     }
     if (FIXNUM_P(val)) {
         long l = FIX2LONG(val);
@@ -2934,9 +2983,9 @@ rb_cmpint(VALUE val, VALUE a, VALUE b)
         return 0;
     }
     if (RB_BIGNUM_TYPE_P(val)) {
-	if (BIGZEROP(val)) return 0;
-	if (BIGNUM_SIGN(val)) return 1;
-	return -1;
+        if (BIGZEROP(val)) return 0;
+        if (BIGNUM_SIGN(val)) return 1;
+        return -1;
     }
     if (RTEST(rb_funcall(val, '>', 1, INT2FIX(0)))) return 1;
     if (RTEST(rb_funcall(val, '<', 1, INT2FIX(0)))) return -1;
@@ -2944,44 +2993,76 @@ rb_cmpint(VALUE val, VALUE a, VALUE b)
 }
 
 #define BIGNUM_SET_LEN(b,l) \
-    ((RBASIC(b)->flags & BIGNUM_EMBED_FLAG) ? \
+    (BIGNUM_EMBED_P(b) ? \
      (void)(RBASIC(b)->flags = \
-	    (RBASIC(b)->flags & ~BIGNUM_EMBED_LEN_MASK) | \
-	    ((l) << BIGNUM_EMBED_LEN_SHIFT)) : \
+            (RBASIC(b)->flags & ~BIGNUM_EMBED_LEN_MASK) | \
+            ((l) << BIGNUM_EMBED_LEN_SHIFT)) : \
      (void)(RBIGNUM(b)->as.heap.len = (l)))
 
+static size_t
+big_embed_capa(VALUE big)
+{
+    size_t size = rb_gc_obj_slot_size(big) - offsetof(struct RBignum, as.ary);
+    RUBY_ASSERT(size % sizeof(BDIGIT) == 0);
+    size_t capa = size / sizeof(BDIGIT);
+    RUBY_ASSERT(capa <= BIGNUM_EMBED_LEN_MAX);
+    return capa;
+}
+
+static size_t
+big_embed_size(size_t capa)
+{
+    size_t size = offsetof(struct RBignum, as.ary) + (sizeof(BDIGIT) * capa);
+    if (size < sizeof(struct RBignum)) {
+        size = sizeof(struct RBignum);
+    }
+    return size;
+}
+
+static bool
+big_embeddable_p(size_t capa)
+{
+    if (capa > BIGNUM_EMBED_LEN_MAX) {
+        return false;
+    }
+    return rb_gc_size_allocatable_p(big_embed_size(capa));
+}
+
 static void
 rb_big_realloc(VALUE big, size_t len)
 {
     BDIGIT *ds;
-    if (RBASIC(big)->flags & BIGNUM_EMBED_FLAG) {
-	if (BIGNUM_EMBED_LEN_MAX < len) {
-	    ds = ALLOC_N(BDIGIT, len);
-	    MEMCPY(ds, RBIGNUM(big)->as.ary, BDIGIT, BIGNUM_EMBED_LEN_MAX);
-	    RBIGNUM(big)->as.heap.len = BIGNUM_LEN(big);
-	    RBIGNUM(big)->as.heap.digits = ds;
-	    RBASIC(big)->flags &= ~BIGNUM_EMBED_FLAG;
-	}
+    size_t embed_capa = big_embed_capa(big);
+
+    if (BIGNUM_EMBED_P(big)) {
+        if (embed_capa < len) {
+            ds = ALLOC_N(BDIGIT, len);
+            MEMCPY(ds, RBIGNUM(big)->as.ary, BDIGIT, embed_capa);
+            RBIGNUM(big)->as.heap.len = BIGNUM_LEN(big);
+            RBIGNUM(big)->as.heap.digits = ds;
+            FL_UNSET_RAW(big, BIGNUM_EMBED_FLAG);
+        }
     }
     else {
-	if (len <= BIGNUM_EMBED_LEN_MAX) {
-	    ds = RBIGNUM(big)->as.heap.digits;
-	    RBASIC(big)->flags |= BIGNUM_EMBED_FLAG;
-	    BIGNUM_SET_LEN(big, len);
-            (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, sizeof(RBIGNUM(big)->as.ary));
-	    if (ds) {
-		MEMCPY(RBIGNUM(big)->as.ary, ds, BDIGIT, len);
-		xfree(ds);
-	    }
-	}
-	else {
-	    if (BIGNUM_LEN(big) == 0) {
-		RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
-	    }
-	    else {
-		REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len);
-	    }
-	}
+        if (len <= embed_capa) {
+            ds = RBIGNUM(big)->as.heap.digits;
+            size_t old_len = RBIGNUM(big)->as.heap.len;
+            FL_SET_RAW(big, BIGNUM_EMBED_FLAG);
+            BIGNUM_SET_LEN(big, len);
+            (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, embed_capa * sizeof(BDIGIT));
+            if (ds) {
+                MEMCPY(RBIGNUM(big)->as.ary, ds, BDIGIT, len);
+                SIZED_FREE_N(ds, old_len);
+            }
+        }
+        else {
+            if (BIGNUM_LEN(big) == 0) {
+                RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
+            }
+            else if (BIGNUM_LEN(big) != len) {
+                SIZED_REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len, BIGNUM_LEN(big));
+            }
+        }
     }
 }
 
@@ -2995,25 +3076,34 @@ rb_big_resize(VALUE big, size_t len)
 static VALUE
 bignew_1(VALUE klass, size_t len, int sign)
 {
-    NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM | (RGENGC_WB_PROTECTED_BIGNUM ? FL_WB_PROTECTED : 0));
-    BIGNUM_SET_SIGN(big, sign);
-    if (len <= BIGNUM_EMBED_LEN_MAX) {
-	RBASIC(big)->flags |= BIGNUM_EMBED_FLAG;
-	BIGNUM_SET_LEN(big, len);
-        (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, sizeof(RBIGNUM(big)->as.ary));
+    VALUE bigv;
+
+    if (big_embeddable_p(len)) {
+        size_t size = big_embed_size(len);
+        RUBY_ASSERT(rb_gc_size_allocatable_p(size));
+        NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM | BIGNUM_EMBED_FLAG, size);
+        bigv = (VALUE)big;
+        BIGNUM_SET_SIGN(bigv, sign);
+        BIGNUM_SET_LEN(bigv, len);
+        (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)big->as.ary, len * sizeof(BDIGIT));
     }
     else {
-	RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
-	RBIGNUM(big)->as.heap.len = len;
+        NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM, sizeof(struct RBignum));
+        bigv = (VALUE)big;
+        BIGNUM_SET_SIGN(bigv, sign);
+        big->as.heap.digits = ALLOC_N(BDIGIT, len);
+        big->as.heap.len = len;
     }
-    OBJ_FREEZE(big);
-    return (VALUE)big;
+    OBJ_FREEZE(bigv);
+    return bigv;
 }
 
 VALUE
 rb_big_new(size_t len, int sign)
 {
-    return bignew(len, sign != 0);
+    VALUE obj = bignew(len, sign != 0);
+    memset(BIGNUM_DIGITS(obj), 0, len * sizeof(BDIGIT));
+    return obj;
 }
 
 VALUE
@@ -3066,7 +3156,7 @@ abs2twocomp(VALUE *xp, long *n_ret)
         MEMCPY(BDIGITS(z), ds, BDIGIT, n);
         bary_2comp(BDIGITS(z), n);
         hibits = BDIGMAX;
-	*xp = z;
+        *xp = z;
     }
     *n_ret = n;
     return hibits;
@@ -3090,7 +3180,7 @@ bigtrunc(VALUE x)
     if (len == 0) return x;
     while (--len && !ds[len]);
     if (BIGNUM_LEN(x) > len+1) {
-	rb_big_resize(x, len+1);
+        rb_big_resize(x, len+1);
     }
     return x;
 }
@@ -3143,7 +3233,7 @@ static VALUE
 bignorm(VALUE x)
 {
     if (RB_BIGNUM_TYPE_P(x)) {
-	x = bigfixize(x);
+        x = bigfixize(x);
     }
     return x;
 }
@@ -3165,8 +3255,8 @@ rb_uint2big(uintptr_t n)
     digits[0] = n;
 #else
     for (i = 0; i < bdigit_roomof(SIZEOF_VALUE); i++) {
-	digits[i] = BIGLO(n);
-	n = BIGDN(n);
+        digits[i] = BIGLO(n);
+        n = BIGDN(n);
     }
 #endif
 
@@ -3185,14 +3275,14 @@ rb_int2big(intptr_t n)
 
     if (n < 0) {
         u = 1 + (VALUE)(-(n + 1)); /* u = -n avoiding overflow */
-	neg = 1;
+        neg = 1;
     }
     else {
         u = n;
     }
     big = rb_uint2big(u);
     if (neg) {
-	BIGNUM_SET_NEGATIVE_SIGN(big);
+        BIGNUM_SET_NEGATIVE_SIGN(big);
     }
     return big;
 }
@@ -3351,7 +3441,7 @@ absint_numwords_generic(size_t numbytes, int nlz_bits_in_msbyte, size_t word_num
 
     if (sign == 2) {
 #if defined __GNUC__ && (__GNUC__ == 4 && __GNUC_MINOR__ == 4)
-	*nlz_bits_ret = 0;
+        *nlz_bits_ret = 0;
 #endif
         return (size_t)-1;
     }
@@ -3384,7 +3474,7 @@ rb_absint_numwords(VALUE val, size_t word_numbits, size_t *nlz_bits_ret)
     size_t numbytes;
     int nlz_bits_in_msbyte;
     size_t numwords;
-    size_t nlz_bits;
+    size_t nlz_bits = 0;
 
     if (word_numbits == 0)
         return (size_t)-1;
@@ -3393,14 +3483,13 @@ rb_absint_numwords(VALUE val, size_t word_numbits, size_t *nlz_bits_ret)
 
     if (numbytes <= SIZE_MAX / CHAR_BIT) {
         numwords = absint_numwords_small(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits);
-#ifdef DEBUG_INTEGER_PACK
-        {
+        if (debug_integer_pack) {
             size_t numwords0, nlz_bits0;
             numwords0 = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits0);
-            assert(numwords0 == numwords);
-            assert(nlz_bits0 == nlz_bits);
+            RUBY_ASSERT(numwords0 == numwords);
+            RUBY_ASSERT(nlz_bits0 == nlz_bits);
+            (void)numwords0;
         }
-#endif
     }
     else {
         numwords = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits);
@@ -3586,7 +3675,7 @@ rb_integer_pack(VALUE val, void *words, size_t numwords, size_t wordsize, size_t
 }
 
 /*
- * Import an integer into a buffer.
+ * Import an integer from a buffer.
  *
  * [words] buffer to import.
  * [numwords] the size of given buffer as number of words.
@@ -3670,7 +3759,7 @@ rb_integer_unpack(const void *words, size_t numwords, size_t wordsize, size_t na
         }
         else if (num_bdigits == numberof(fixbuf)) {
             val = bignew((long)num_bdigits+1, 0);
-	    MEMCPY(BDIGITS(val), fixbuf, BDIGIT, num_bdigits);
+            MEMCPY(BDIGITS(val), fixbuf, BDIGIT, num_bdigits);
             BDIGITS(val)[num_bdigits++] = 1;
         }
         else {
@@ -3682,11 +3771,11 @@ rb_integer_unpack(const void *words, size_t numwords, size_t wordsize, size_t na
         BDIGIT_DBL u = fixbuf[0] + BIGUP(fixbuf[1]);
         if (u == 0)
             return LONG2FIX(0);
-	if (0 < sign && POSFIXABLE(u))
-            return LONG2FIX(u);
-	if (sign < 0 && BDIGIT_MSB(fixbuf[1]) == 0 &&
+        if (0 < sign && POSFIXABLE(u))
+            return LONG2FIX((long)u);
+        if (sign < 0 && BDIGIT_MSB(fixbuf[1]) == 0 &&
                 NEGFIXABLE(-(BDIGIT_DBL_SIGNED)u))
-            return LONG2FIX(-(BDIGIT_DBL_SIGNED)u);
+            return LONG2FIX((long)-(BDIGIT_DBL_SIGNED)u);
         val = bignew((long)num_bdigits, 0 <= sign);
         MEMCPY(BDIGITS(val), fixbuf, BDIGIT, num_bdigits);
     }
@@ -3736,42 +3825,41 @@ str2big_scan_digits(const char *s, const char *str, int base, int badcheck, size
     int c;
 
     if (!len) {
-	*num_digits_p = 0;
-	*len_p = 0;
-	return TRUE;
+        *num_digits_p = 0;
+        *len_p = 0;
+        return TRUE;
     }
 
-    if (badcheck && *str == '_') goto bad;
+    if (badcheck && *str == '_') return FALSE;
 
     while ((c = *str++) != 0) {
-	if (c == '_') {
-	    if (nondigit) {
-		if (badcheck) goto bad;
-		break;
-	    }
-	    nondigit = (char) c;
-	}
-	else if ((c = conv_digit(c)) < 0 || c >= base) {
-	    break;
-	}
-	else {
-	    nondigit = 0;
-	    num_digits++;
-	    digits_end = str;
-	}
-	if (len > 0 && !--len) break;
-    }
-    if (badcheck && nondigit) goto bad;
+        if (c == '_') {
+            if (nondigit) {
+                if (badcheck) return FALSE;
+                break;
+            }
+            nondigit = (char) c;
+        }
+        else if ((c = conv_digit(c)) < 0 || c >= base) {
+            break;
+        }
+        else {
+            nondigit = 0;
+            num_digits++;
+            digits_end = str;
+        }
+        if (len > 0 && !--len) break;
+    }
+    if (badcheck && nondigit) return FALSE;
     if (badcheck && len) {
-	str--;
-	while (*str && ISSPACE(*str)) {
-	    str++;
-	    if (len > 0 && !--len) break;
-	}
-	if (len && *str) {
-	  bad:
-	    return FALSE;
-	}
+        str--;
+        while (*str && ISSPACE(*str)) {
+            str++;
+            if (len > 0 && !--len) break;
+        }
+        if (len && *str) {
+            return FALSE;
+        }
     }
     *num_digits_p = num_digits;
     *len_p = digits_end - digits_start;
@@ -3814,7 +3902,7 @@ str2big_poweroftwo(
     if (numbits) {
         *dp++ = BIGLO(dd);
     }
-    assert((size_t)(dp - BDIGITS(z)) == num_bdigits);
+    RUBY_ASSERT((size_t)(dp - BDIGITS(z)) == num_bdigits);
 
     return z;
 }
@@ -3857,7 +3945,7 @@ str2big_normal(
             }
             break;
         }
-        assert(blen <= num_bdigits);
+        RUBY_ASSERT(blen <= num_bdigits);
     }
 
     return z;
@@ -3915,7 +4003,7 @@ str2big_karatsuba(
             current_base = 1;
         }
     }
-    assert(i == num_bdigits);
+    RUBY_ASSERT(i == num_bdigits);
     for (unit = 2; unit < num_bdigits; unit *= 2) {
         for (i = 0; i < num_bdigits; i += unit*2) {
             if (2*unit <= num_bdigits - i) {
@@ -3946,7 +4034,7 @@ str2big_karatsuba(
     return z;
 }
 
-#ifdef USE_GMP
+#if USE_GMP
 static VALUE
 str2big_gmp(
     int sign,
@@ -3956,7 +4044,6 @@ str2big_gmp(
     size_t num_bdigits,
     int base)
 {
-    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
     char *buf, *p;
     const char *q;
     VALUE tmps;
@@ -3979,7 +4066,7 @@ str2big_gmp(
     zn = num_bdigits;
     z = bignew(zn, sign);
     zds = BDIGITS(z);
-    mpz_export(BDIGITS(z), &count, -1, sizeof(BDIGIT), 0, nails, mz);
+    bdigits_from_mpz(mz, BDIGITS(z), &count);
     BDIGITS_ZERO(zds+count, zn-count);
     mpz_clear(mz);
 
@@ -3990,6 +4077,8 @@ str2big_gmp(
 }
 #endif
 
+static VALUE rb_cstr_parse_inum(const char *str, ssize_t len, char **endp, int base);
+
 /*
  * Parse +str+ as Ruby Integer, i.e., underscores, 0d and 0b prefixes.
  *
@@ -4012,8 +4101,8 @@ rb_cstr_to_inum(const char *str, int base, int badcheck)
     char *end;
     VALUE ret = rb_cstr_parse_inum(str, -1, (badcheck ? NULL : &end), base);
     if (NIL_P(ret)) {
-	if (badcheck) rb_invalid_str(str, "Integer()");
-	ret = INT2FIX(0);
+        if (badcheck) rb_invalid_str(str, "Integer()");
+        ret = INT2FIX(0);
     }
     return ret;
 }
@@ -4037,7 +4126,7 @@ rb_cstr_to_inum(const char *str, int base, int badcheck)
 
 VALUE
 rb_int_parse_cstr(const char *str, ssize_t len, char **endp, size_t *ndigits,
-		  int base, int flags)
+                  int base, int flags)
 {
     const char *const s = str;
     char sign = 1;
@@ -4054,85 +4143,82 @@ rb_int_parse_cstr(const char *str, ssize_t len, char **endp, size_t *ndigits,
     const int badcheck = !endp;
 
 #define ADV(n) do {\
-	if (len > 0 && len <= (n)) goto bad; \
-	str += (n); \
-	len -= (n); \
+        if (len > 0 && len <= (n)) goto bad; \
+        str += (n); \
+        len -= (n); \
     } while (0)
 #define ASSERT_LEN() do {\
-	assert(len != 0); \
-	if (len0 >= 0) assert(s + len0 == str + len); \
+        RUBY_ASSERT(len != 0); \
+        if (len0 >= 0) RUBY_ASSERT(s + len0 == str + len); \
     } while (0)
 
     if (!str) {
-      bad:
-	if (endp) *endp = (char *)str;
-	if (ndigits) *ndigits = num_digits;
-	return z;
+        goto bad;
     }
     if (len && (flags & RB_INT_PARSE_SIGN)) {
-	while (ISSPACE(*str)) ADV(1);
+        while (ISSPACE(*str)) ADV(1);
 
-	if (str[0] == '+') {
-	    ADV(1);
-	}
-	else if (str[0] == '-') {
-	    ADV(1);
-	    sign = 0;
-	}
-	ASSERT_LEN();
+        if (str[0] == '+') {
+            ADV(1);
+        }
+        else if (str[0] == '-') {
+            ADV(1);
+            sign = 0;
+        }
+        ASSERT_LEN();
     }
     if (base <= 0) {
-	if (str[0] == '0' && len > 1) {
-	    switch (str[1]) {
-	      case 'x': case 'X':
-		base = 16;
-		ADV(2);
-		break;
-	      case 'b': case 'B':
-		base = 2;
-		ADV(2);
-		break;
-	      case 'o': case 'O':
-		base = 8;
-		ADV(2);
-		break;
-	      case 'd': case 'D':
-		base = 10;
-		ADV(2);
-		break;
-	      default:
-		base = 8;
-	    }
-	}
-	else if (base < -1) {
-	    base = -base;
-	}
-	else {
-	    base = 10;
-	}
+        if (str[0] == '0' && len > 1) {
+            switch (str[1]) {
+              case 'x': case 'X':
+                base = 16;
+                ADV(2);
+                break;
+              case 'b': case 'B':
+                base = 2;
+                ADV(2);
+                break;
+              case 'o': case 'O':
+                base = 8;
+                ADV(2);
+                break;
+              case 'd': case 'D':
+                base = 10;
+                ADV(2);
+                break;
+              default:
+                base = 8;
+            }
+        }
+        else if (base < -1) {
+            base = -base;
+        }
+        else {
+            base = 10;
+        }
     }
     else if (len == 1 || !(flags & RB_INT_PARSE_PREFIX)) {
-	/* no prefix */
+        /* no prefix */
     }
     else if (base == 2) {
-	if (str[0] == '0' && (str[1] == 'b'||str[1] == 'B')) {
-	    ADV(2);
-	}
+        if (str[0] == '0' && (str[1] == 'b'||str[1] == 'B')) {
+            ADV(2);
+        }
     }
     else if (base == 8) {
-	if (str[0] == '0' && (str[1] == 'o'||str[1] == 'O')) {
-	    ADV(2);
-	}
+        if (str[0] == '0' && (str[1] == 'o'||str[1] == 'O')) {
+            ADV(2);
+        }
     }
     else if (base == 10) {
-	if (str[0] == '0' && (str[1] == 'd'||str[1] == 'D')) {
-	    ADV(2);
-	}
+        if (str[0] == '0' && (str[1] == 'd'||str[1] == 'D')) {
+            ADV(2);
+        }
     }
     else if (base == 16) {
-	if (str[0] == '0' && (str[1] == 'x'||str[1] == 'X')) {
-	    ADV(2);
-	}
+        if (str[0] == '0' && (str[1] == 'x'||str[1] == 'X')) {
+            ADV(2);
+        }
     }
     if (!valid_radix_p(base)) {
         invalid_radix(base);
@@ -4140,80 +4226,79 @@ rb_int_parse_cstr(const char *str, ssize_t len, char **endp, size_t *ndigits,
     if (!len) goto bad;
     num_digits = str - s;
     if (*str == '0' && len != 1) { /* squeeze preceding 0s */
-	int us = 0;
-	const char *end = len < 0 ? NULL : str + len;
-	++num_digits;
-	while ((c = *++str) == '0' ||
-	       ((flags & RB_INT_PARSE_UNDERSCORE) && c == '_')) {
-	    if (c == '_') {
-		if (++us >= 2)
-		    break;
-	    }
-	    else {
-		++num_digits;
-		us = 0;
-	    }
-	    if (str == end) break;
-	}
-	if (!c || ISSPACE(c)) --str;
-	if (end) len = end - str;
-	ASSERT_LEN();
+        int us = 0;
+        const char *end = len < 0 ? NULL : str + len;
+        ++num_digits;
+        while ((c = *++str) == '0' ||
+               ((flags & RB_INT_PARSE_UNDERSCORE) && c == '_')) {
+            if (c == '_') {
+                if (++us >= 2)
+                    break;
+            }
+            else {
+                ++num_digits;
+                us = 0;
+            }
+            if (str == end) break;
+        }
+        if (!c || ISSPACE(c)) --str;
+        if (end) len = end - str;
     }
     c = *str;
     c = conv_digit(c);
     if (c < 0 || c >= base) {
-	if (!badcheck && num_digits) z = INT2FIX(0);
-	goto bad;
+        if (!badcheck && num_digits) z = INT2FIX(0);
+        goto bad;
     }
 
     if (ndigits) *ndigits = num_digits;
     val = ruby_scan_digits(str, len, base, &num_digits, &ov);
     if (!ov) {
-	const char *end = &str[num_digits];
-	if (num_digits > 0 && *end == '_' && (flags & RB_INT_PARSE_UNDERSCORE))
-	    goto bigparse;
-	if (endp) *endp = (char *)end;
-	if (ndigits) *ndigits += num_digits;
-	if (badcheck) {
-	    if (num_digits == 0) return Qnil; /* no number */
-	    while (len < 0 ? *end : end < str + len) {
-		if (!ISSPACE(*end)) return Qnil; /* trailing garbage */
-		end++;
-	    }
-	}
-
-	if (POSFIXABLE(val)) {
-	    if (sign) return LONG2FIX(val);
-	    else {
-		long result = -(long)val;
-		return LONG2FIX(result);
-	    }
-	}
-	else {
-	    VALUE big = rb_uint2big(val);
-	    BIGNUM_SET_SIGN(big, sign);
-	    return bignorm(big);
-	}
+        const char *end = &str[num_digits];
+        if (num_digits > 0 && *end == '_' && (flags & RB_INT_PARSE_UNDERSCORE))
+            goto bigparse;
+        if (endp) *endp = (char *)end;
+        if (ndigits) *ndigits += num_digits;
+        if (badcheck) {
+            if (num_digits == 0) return Qnil; /* no number */
+            while (len < 0 ? *end : end < str + len) {
+                if (!ISSPACE(*end)) return Qnil; /* trailing garbage */
+                end++;
+            }
+        }
+
+        if (POSFIXABLE(val)) {
+            if (sign) return LONG2FIX(val);
+            else {
+                long result = -(long)val;
+                return LONG2FIX(result);
+            }
+        }
+        else {
+            VALUE big = rb_uint2big(val);
+            BIGNUM_SET_SIGN(big, sign);
+            return bignorm(big);
+        }
     }
 
   bigparse:
     digits_start = str;
     if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
-	goto bad;
+        goto bad;
     if (endp) *endp = (char *)(str + len);
     if (ndigits) *ndigits += num_digits;
     digits_end = digits_start + len;
 
     if (POW2_P(base)) {
         z = str2big_poweroftwo(sign, digits_start, digits_end, num_digits,
-			       bit_length(base-1));
+                               bit_length(base-1));
     }
     else {
         int digits_per_bdigits_dbl;
         maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
         num_bdigits = roomof(num_digits, digits_per_bdigits_dbl)*2;
 
-#ifdef USE_GMP
+#if USE_GMP
         if (GMP_STR2BIG_DIGITS < num_bdigits) {
             z = str2big_gmp(sign, digits_start, digits_end, num_digits,
                     num_bdigits, base);
@@ -4231,13 +4316,18 @@ rb_int_parse_cstr(const char *str, ssize_t len, char **endp, size_t *ndigits,
     }
 
     return bignorm(z);
+
+  bad:
+    if (endp) *endp = (char *)str;
+    if (ndigits) *ndigits = num_digits;
+    return z;
 }
 
-VALUE
+static VALUE
 rb_cstr_parse_inum(const char *str, ssize_t len, char **endp, int base)
 {
     return rb_int_parse_cstr(str, len, endp, NULL, base,
-			     RB_INT_PARSE_DEFAULT);
+                             RB_INT_PARSE_DEFAULT);
 }
 
 VALUE
@@ -4286,14 +4376,14 @@ rb_str2big_poweroftwo(VALUE arg, int base, int badcheck)
     s = str = StringValueCStr(arg);
     len = RSTRING_LEN(arg);
     if (*str == '-') {
-	len--;
+        len--;
         str++;
         positive_p = 0;
     }
 
     digits_start = str;
     if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
-	invalid_integer(arg);
+        invalid_integer(arg);
     digits_end = digits_start + len;
 
     z = str2big_poweroftwo(positive_p, digits_start, digits_end, num_digits,
@@ -4325,14 +4415,14 @@ rb_str2big_normal(VALUE arg, int base, int badcheck)
     s = str = StringValuePtr(arg);
     len = RSTRING_LEN(arg);
     if (len > 0 && *str == '-') {
-	len--;
+        len--;
         str++;
         positive_p = 0;
     }
 
     digits_start = str;
     if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
-	invalid_integer(arg);
+        invalid_integer(arg);
     digits_end = digits_start + len;
 
     maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
@@ -4367,14 +4457,14 @@ rb_str2big_karatsuba(VALUE arg, int base, int badcheck)
     s = str = StringValuePtr(arg);
     len = RSTRING_LEN(arg);
     if (len > 0 && *str == '-') {
-	len--;
+        len--;
         str++;
         positive_p = 0;
     }
 
     digits_start = str;
     if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
-	invalid_integer(arg);
+        invalid_integer(arg);
     digits_end = digits_start + len;
 
     maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
@@ -4388,7 +4478,7 @@ rb_str2big_karatsuba(VALUE arg, int base, int badcheck)
     return bignorm(z);
 }
 
-#ifdef USE_GMP
+#if USE_GMP
 VALUE
 rb_str2big_gmp(VALUE arg, int base, int badcheck)
 {
@@ -4410,14 +4500,14 @@ rb_str2big_gmp(VALUE arg, int base, int badcheck)
     s = str = StringValuePtr(arg);
     len = RSTRING_LEN(arg);
     if (len > 0 && *str == '-') {
-	len--;
+        len--;
         str++;
         positive_p = 0;
     }
 
     digits_start = str;
     if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
-	invalid_integer(arg);
+        invalid_integer(arg);
     digits_end = digits_start + len;
 
     maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
@@ -4433,7 +4523,7 @@ rb_str2big_gmp(VALUE arg, int base, int badcheck)
 
 #if HAVE_LONG_LONG
 
-static VALUE
+VALUE
 rb_ull2big(unsigned LONG_LONG n)
 {
     long i;
@@ -4444,8 +4534,8 @@ rb_ull2big(unsigned LONG_LONG n)
     digits[0] = n;
 #else
     for (i = 0; i < bdigit_roomof(SIZEOF_LONG_LONG); i++) {
-	digits[i] = BIGLO(n);
-	n = BIGDN(n);
+        digits[i] = BIGLO(n);
+        n = BIGDN(n);
     }
 #endif
 
@@ -4455,7 +4545,7 @@ rb_ull2big(unsigned LONG_LONG n)
     return big;
 }
 
-static VALUE
+VALUE
 rb_ll2big(LONG_LONG n)
 {
     long neg = 0;
@@ -4464,14 +4554,14 @@ rb_ll2big(LONG_LONG n)
 
     if (n < 0) {
         u = 1 + (unsigned LONG_LONG)(-(n + 1)); /* u = -n avoiding overflow */
-	neg = 1;
+        neg = 1;
     }
     else {
         u = n;
     }
     big = rb_ull2big(u);
     if (neg) {
-	BIGNUM_SET_NEGATIVE_SIGN(big);
+        BIGNUM_SET_NEGATIVE_SIGN(big);
     }
     return big;
 }
@@ -4479,21 +4569,21 @@ rb_ll2big(LONG_LONG n)
 VALUE
 rb_ull2inum(unsigned LONG_LONG n)
 {
-    if (POSFIXABLE(n)) return LONG2FIX(n);
+    if (POSFIXABLE(n)) return LONG2FIX((long)n);
     return rb_ull2big(n);
 }
 
 VALUE
 rb_ll2inum(LONG_LONG n)
 {
-    if (FIXABLE(n)) return LONG2FIX(n);
+    if (FIXABLE(n)) return LONG2FIX((long)n);
     return rb_ll2big(n);
 }
 
 #endif  /* HAVE_LONG_LONG */
 
 #ifdef HAVE_INT128_T
-static VALUE
+VALUE
 rb_uint128t2big(uint128_t n)
 {
     long i;
@@ -4501,7 +4591,7 @@ rb_uint128t2big(uint128_t n)
     BDIGIT *digits = BDIGITS(big);
 
     for (i = 0; i < bdigit_roomof(SIZEOF_INT128_T); i++) {
-	digits[i] = BIGLO(RSHIFT(n ,BITSPERDIG*i));
+        digits[i] = BIGLO(RSHIFT(n ,BITSPERDIG*i));
     }
 
     i = bdigit_roomof(SIZEOF_INT128_T);
@@ -4510,7 +4600,7 @@ rb_uint128t2big(uint128_t n)
     return big;
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_int128t2big(int128_t n)
 {
     int neg = 0;
@@ -4519,14 +4609,14 @@ rb_int128t2big(int128_t n)
 
     if (n < 0) {
         u = 1 + (uint128_t)(-(n + 1)); /* u = -n avoiding overflow */
-	neg = 1;
+        neg = 1;
     }
     else {
         u = n;
     }
     big = rb_uint128t2big(u);
     if (neg) {
-	BIGNUM_SET_NEGATIVE_SIGN(big);
+        BIGNUM_SET_NEGATIVE_SIGN(big);
     }
     return big;
 }
@@ -4555,11 +4645,14 @@ big_shift3(VALUE x, int lshift_p, size_t shift_numdigits, int shift_numbits)
 
     if (lshift_p) {
         if (LONG_MAX < shift_numdigits) {
-            rb_raise(rb_eArgError, "too big number");
+          too_big:
+            rb_raise(rb_eRangeError, "shift width too big");
         }
         s1 = shift_numdigits;
         s2 = shift_numbits;
+        if ((size_t)s1 != shift_numdigits) goto too_big;
         xn = BIGNUM_LEN(x);
+        if (LONG_MAX/SIZEOF_BDIGIT <= xn+s1) goto too_big;
         z = bignew(xn+s1+1, BIGNUM_SIGN(x));
         zds = BDIGITS(z);
         BDIGITS_ZERO(zds, s1);
@@ -4601,8 +4694,8 @@ big_shift2(VALUE x, int lshift_p, VALUE y)
     size_t shift_numdigits;
     int shift_numbits;
 
-    assert(POW2_P(CHAR_BIT));
-    assert(POW2_P(BITSPERDIG));
+    RUBY_ASSERT(POW2_P(CHAR_BIT));
+    RUBY_ASSERT(POW2_P(BITSPERDIG));
 
     if (BIGZEROP(x))
         return INT2FIX(0);
@@ -4650,12 +4743,6 @@ static size_t base36_numdigits_cache[35][MAX_BASE36_POWER_TABLE_ENTRIES];
 static void
 power_cache_init(void)
 {
-    int i, j;
-    for (i = 0; i < 35; ++i) {
-	for (j = 0; j < MAX_BASE36_POWER_TABLE_ENTRIES; ++j) {
-	    base36_power_cache[i][j] = Qnil;
-	}
-    }
 }
 
 static inline VALUE
@@ -4678,8 +4765,8 @@ power_cache_get_power(int base, int power_level, size_t *numdigits_ret)
     if (MAX_BASE36_POWER_TABLE_ENTRIES <= power_level)
         rb_bug("too big power number requested: maxpow_in_bdigit_dbl(%d)**(2**%d)", base, power_level);
 
-    if (NIL_P(base36_power_cache[base - 2][power_level])) {
-        VALUE power;
+    VALUE power = base36_power_cache[base - 2][power_level];
+    if (!power) {
         size_t numdigits;
         if (power_level == 0) {
             int numdigits0;
@@ -4695,11 +4782,11 @@ power_cache_get_power(int base, int power_level, size_t *numdigits_ret)
         rb_obj_hide(power);
         base36_power_cache[base - 2][power_level] = power;
         base36_numdigits_cache[base - 2][power_level] = numdigits;
-	rb_gc_register_mark_object(power);
+        rb_vm_register_global_object(power);
     }
     if (numdigits_ret)
         *numdigits_ret = base36_numdigits_cache[base - 2][power_level];
-    return base36_power_cache[base - 2][power_level];
+    return power;
 }
 
 struct big2str_struct {
@@ -4731,7 +4818,7 @@ big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t tail
     int beginning = !b2s->ptr;
     size_t len = 0;
 
-    assert(xn <= 2);
+    RUBY_ASSERT(xn <= 2);
     num = bary2bdigitdbl(xds, xn);
 
     if (beginning) {
@@ -4739,23 +4826,74 @@ big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t tail
             return;
         p = buf;
         j = sizeof(buf);
-        do {
-            BDIGIT_DBL idx = num % b2s->base;
-            num /= b2s->base;
-            p[--j] = ruby_digitmap[idx];
-        } while (num);
+        if (b2s->base == 10) {
+            /* Emit two decimal digits per iteration from ruby_decimal_digit_pairs.
+             * See the comment on the table in bignum.c near ruby_digitmap. */
+            while (num >= 100) {
+                BDIGIT_DBL idx = (num % 100) * 2;
+                num /= 100;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            if (num >= 10) {
+                BDIGIT_DBL idx = num * 2;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            else {
+                /* num is 1..9 here (0 was handled above) */
+                p[--j] = (char)('0' + num);
+            }
+        }
+        else {
+            do {
+                BDIGIT_DBL idx = num % b2s->base;
+                num /= b2s->base;
+                p[--j] = ruby_digitmap[idx];
+            } while (num);
+        }
         len = sizeof(buf) - j;
         big2str_alloc(b2s, len + taillen);
-	MEMCPY(b2s->ptr, buf + j, char, len);
+        MEMCPY(b2s->ptr, buf + j, char, len);
     }
     else {
         p = b2s->ptr;
         j = b2s->hbase2_numdigits;
-        do {
-            BDIGIT_DBL idx = num % b2s->base;
-            num /= b2s->base;
-            p[--j] = ruby_digitmap[idx];
-        } while (j);
+        if (b2s->base == 10) {
+            /* Non-beginning chunks must emit EXACTLY hbase2_numdigits,
+             * zero-padded on the left.  Consume num in 2-digit groups,
+             * handle the odd trailing digit, then memset remaining
+             * positions with '0'. */
+            while (num >= 100) {
+                BDIGIT_DBL idx = (num % 100) * 2;
+                num /= 100;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            if (num >= 10) {
+                BDIGIT_DBL idx = num * 2;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            else if (num > 0) {
+                p[--j] = (char)('0' + num);
+            }
+            if (j > 0) {
+                memset(p, '0', j);
+                j = 0;
+            }
+        }
+        else {
+            do {
+                BDIGIT_DBL idx = num % b2s->base;
+                num /= b2s->base;
+                p[--j] = ruby_digitmap[idx];
+            } while (j);
+        }
         len = b2s->hbase2_numdigits;
     }
     b2s->ptr += len;
@@ -4763,7 +4901,7 @@ big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t tail
 
 static void
 big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
-		  int power_level, size_t taillen)
+                  int power_level, size_t taillen)
 {
     VALUE b;
     size_t half_numdigits, lower_numdigits;
@@ -4793,17 +4931,17 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
      */
 
     if (xn == 0 || bary_zero_p(xds, xn)) {
-	if (b2s->ptr) {
+        if (b2s->ptr) {
             /* When x is zero, power_cache_get_power(base, power_level) should be cached already. */
             power_cache_get_power(b2s->base, power_level, &len);
-	    memset(b2s->ptr, '0', len);
+            memset(b2s->ptr, '0', len);
             b2s->ptr += len;
-	}
+        }
         return;
     }
 
     if (power_level == 0) {
-	big2str_2bdigits(b2s, xds, xn, taillen);
+        big2str_2bdigits(b2s, xds, xn, taillen);
         return;
     }
 
@@ -4831,7 +4969,7 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
             memset(b2s->ptr, '0', len);
             b2s->ptr += len;
         }
-	big2str_2bdigits(b2s, xds, xn, taillen);
+        big2str_2bdigits(b2s, xds, xn, taillen);
     }
     else {
         BDIGIT *qds, *rds;
@@ -4859,7 +4997,7 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
             /* bigdivrem_restoring will modify y.
              * So use temporary buffer.  */
             tds = xds + qn;
-            assert(qn + bn <= xn + wn);
+            RUBY_ASSERT(qn + bn <= xn + wn);
             bary_small_lshift(tds, bds, bn, shift);
             xds[xn] = bary_small_lshift(xds, xds, xn, shift);
         }
@@ -4877,7 +5015,7 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
         }
 
         BARY_TRUNC(qds, qn);
-        assert(qn <= bn);
+        RUBY_ASSERT(qn <= bn);
         big2str_karatsuba(b2s, qds, qn, xn+wn - (rn+qn), lower_power_level, lower_numdigits+taillen);
         BARY_TRUNC(rds, rn);
         big2str_karatsuba(b2s, rds, rn, xn+wn - rn, lower_power_level, taillen);
@@ -4935,14 +5073,14 @@ big2str_generic(VALUE x, int base)
     BARY_TRUNC(xds, xn);
 
     if (xn == 0) {
-	return rb_usascii_str_new2("0");
+        return rb_usascii_str_new2("0");
     }
 
     if (!valid_radix_p(base))
-	invalid_radix(base);
+        invalid_radix(base);
 
     if (xn >= LONG_MAX/BITSPERDIG) {
-        rb_raise(rb_eRangeError, "bignum too big to convert into `string'");
+        rb_raise(rb_eRangeError, "bignum too big to convert into 'string'");
     }
 
     power_level = 0;
@@ -4952,7 +5090,7 @@ big2str_generic(VALUE x, int base)
         power_level++;
         power = power_cache_get_power(base, power_level, NULL);
     }
-    assert(power_level != MAX_BASE36_POWER_TABLE_ENTRIES);
+    RUBY_ASSERT(power_level != MAX_BASE36_POWER_TABLE_ENTRIES);
 
     if ((size_t)BIGNUM_LEN(power) <= xn) {
         /*
@@ -4976,7 +5114,7 @@ big2str_generic(VALUE x, int base)
     b2s_data.ptr = NULL;
 
     if (power_level == 0) {
-	big2str_2bdigits(&b2s_data, xds, xn, 0);
+        big2str_2bdigits(&b2s_data, xds, xn, 0);
     }
     else {
         VALUE tmpw = 0;
@@ -4985,7 +5123,7 @@ big2str_generic(VALUE x, int base)
         wn = power_level * BIGDIVREM_EXTRA_WORDS + BIGNUM_LEN(power);
         wds = ALLOCV_N(BDIGIT, tmpw, xn + wn);
         MEMCPY(wds, xds, BDIGIT, xn);
-	big2str_karatsuba(&b2s_data, wds, xn, wn, power_level, 0);
+        big2str_karatsuba(&b2s_data, wds, xn, wn, power_level, 0);
         if (tmpw)
             ALLOCV_END(tmpw);
     }
@@ -5004,11 +5142,10 @@ rb_big2str_generic(VALUE x, int base)
     return big2str_generic(x, base);
 }
 
-#ifdef USE_GMP
+#if USE_GMP
 static VALUE
 big2str_gmp(VALUE x, int base)
 {
-    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
     mpz_t mx;
     size_t size;
     VALUE str;
@@ -5016,7 +5153,7 @@ big2str_gmp(VALUE x, int base)
     size_t xn = BIGNUM_LEN(x);
 
     mpz_init(mx);
-    mpz_import(mx, xn, -1, sizeof(BDIGIT), 0, nails, xds);
+    bdigits_to_mpz(mx, xds, xn);
 
     size = mpz_sizeinbase(mx, base);
 
@@ -5052,7 +5189,7 @@ rb_big2str1(VALUE x, int base)
     size_t xn;
 
     if (FIXNUM_P(x)) {
-	return rb_fix2str(x, base);
+        return rb_fix2str(x, base);
     }
 
     bigtrunc(x);
@@ -5061,14 +5198,14 @@ rb_big2str1(VALUE x, int base)
     BARY_TRUNC(xds, xn);
 
     if (xn == 0) {
-	return rb_usascii_str_new2("0");
+        return rb_usascii_str_new2("0");
     }
 
     if (!valid_radix_p(base))
-	invalid_radix(base);
+        invalid_radix(base);
 
     if (xn >= LONG_MAX/BITSPERDIG) {
-        rb_raise(rb_eRangeError, "bignum too big to convert into `string'");
+        rb_raise(rb_eRangeError, "bignum too big to convert into 'string'");
     }
 
     if (POW2_P(base)) {
@@ -5076,7 +5213,7 @@ rb_big2str1(VALUE x, int base)
         return big2str_base_poweroftwo(x, base);
     }
 
-#ifdef USE_GMP
+#if USE_GMP
     if (GMP_BIG2STR_DIGITS < xn) {
         return big2str_gmp(x, base);
     }
@@ -5104,7 +5241,7 @@ big2ulong(VALUE x, const char *type)
     if (len == 0)
         return 0;
     if (BIGSIZE(x) > sizeof(long)) {
-        rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
+        rb_raise(rb_eRangeError, "bignum too big to convert into '%s'", type);
     }
     ds = BDIGITS(x);
 #if SIZEOF_LONG <= SIZEOF_BDIGIT
@@ -5112,7 +5249,7 @@ big2ulong(VALUE x, const char *type)
 #else
     num = 0;
     for (i = 0; i < len; i++) {
-	num <<= BITSPERDIG;
+        num <<= BITSPERDIG;
         num += (unsigned long)ds[len - i - 1]; /* overflow is already checked */
     }
 #endif
@@ -5147,7 +5284,7 @@ rb_big2long(VALUE x)
         if (num <= 1+(unsigned long)(-(LONG_MIN+1)))
             return -(long)(num-1)-1;
     }
-    rb_raise(rb_eRangeError, "bignum too big to convert into `long'");
+    rb_raise(rb_eRangeError, "bignum too big to convert into 'long'");
 }
 
 #if HAVE_LONG_LONG
@@ -5165,13 +5302,13 @@ big2ull(VALUE x, const char *type)
     if (len == 0)
         return 0;
     if (BIGSIZE(x) > SIZEOF_LONG_LONG)
-	rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
+        rb_raise(rb_eRangeError, "bignum too big to convert into '%s'", type);
 #if SIZEOF_LONG_LONG <= SIZEOF_BDIGIT
     num = (unsigned LONG_LONG)ds[0];
 #else
     num = 0;
     for (i = 0; i < len; i++) {
-	num = BIGUP(num);
+        num = BIGUP(num);
         num += ds[len - i - 1];
     }
 #endif
@@ -5206,7 +5343,7 @@ rb_big2ll(VALUE x)
         if (num <= 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
             return -(LONG_LONG)(num-1)-1;
     }
-    rb_raise(rb_eRangeError, "bignum too big to convert into `long long'");
+    rb_raise(rb_eRangeError, "bignum too big to convert into 'long long'");
 }
 
 #endif  /* HAVE_LONG_LONG */
@@ -5221,23 +5358,23 @@ dbl2big(double d)
     double u = (d < 0)?-d:d;
 
     if (isinf(d)) {
-	rb_raise(rb_eFloatDomainError, d < 0 ? "-Infinity" : "Infinity");
+        rb_raise(rb_eFloatDomainError, d < 0 ? "-Infinity" : "Infinity");
     }
     if (isnan(d)) {
-	rb_raise(rb_eFloatDomainError, "NaN");
+        rb_raise(rb_eFloatDomainError, "NaN");
     }
 
     while (1.0 <= u) {
-	u /= (double)(BIGRAD);
-	i++;
+        u /= (double)(BIGRAD);
+        i++;
     }
     z = bignew(i, d>=0);
     digits = BDIGITS(z);
     while (i--) {
-	u *= BIGRAD;
-	c = (BDIGIT)u;
-	u -= c;
-	digits[i] = c;
+        u *= BIGRAD;
+        c = (BDIGIT)u;
+        u -= c;
+        digits[i] = c;
     }
 
     return z;
@@ -5257,28 +5394,28 @@ big2dbl(VALUE x)
     BDIGIT *ds = BDIGITS(x), dl;
 
     if (i) {
-	bits = i * BITSPERDIG - nlz(ds[i-1]);
-	if (bits > DBL_MANT_DIG+DBL_MAX_EXP) {
-	    d = HUGE_VAL;
-	}
-	else {
-	    if (bits > DBL_MANT_DIG+1)
-		lo = (bits -= DBL_MANT_DIG+1) / BITSPERDIG;
-	    else
-		bits = 0;
-	    while (--i > lo) {
-		d = ds[i] + BIGRAD*d;
-	    }
-	    dl = ds[i];
-	    if (bits && (dl & ((BDIGIT)1 << (bits %= BITSPERDIG)))) {
-		int carry = (dl & ~(BDIGMAX << bits)) != 0;
-		if (!carry) {
-		    while (i-- > 0) {
-			carry = ds[i] != 0;
-			if (carry) break;
-		    }
-		}
-		if (carry) {
+        bits = i * BITSPERDIG - nlz(ds[i-1]);
+        if (bits > DBL_MANT_DIG+DBL_MAX_EXP) {
+            d = HUGE_VAL;
+        }
+        else {
+            if (bits > DBL_MANT_DIG+1)
+                lo = (bits -= DBL_MANT_DIG+1) / BITSPERDIG;
+            else
+                bits = 0;
+            while (--i > lo) {
+                d = ds[i] + BIGRAD*d;
+            }
+            dl = ds[i];
+            if (bits && (dl & ((BDIGIT)1 << (bits %= BITSPERDIG)))) {
+                int carry = (dl & ~(BDIGMAX << bits)) != 0;
+                if (!carry) {
+                    while (i-- > 0) {
+                        carry = ds[i] != 0;
+                        if (carry) break;
+                    }
+                }
+                if (carry) {
                     BDIGIT mask = BDIGMAX;
                     BDIGIT bit = 1;
                     mask <<= bits;
@@ -5286,19 +5423,19 @@ big2dbl(VALUE x)
                     dl &= mask;
                     dl += bit;
                     dl = BIGLO(dl);
-		    if (!dl) d += 1;
-		}
-	    }
-	    d = dl + BIGRAD*d;
-	    if (lo) {
-		if (lo > INT_MAX / BITSPERDIG)
-		    d = HUGE_VAL;
-		else if (lo < INT_MIN / BITSPERDIG)
-		    d = 0.0;
-		else
-		    d = ldexp(d, (int)(lo * BITSPERDIG));
-	    }
-	}
+                    if (!dl) d += 1;
+                }
+            }
+            d = dl + BIGRAD*d;
+            if (lo) {
+                if (lo > INT_MAX / BITSPERDIG)
+                    d = HUGE_VAL;
+                else if (lo < INT_MIN / BITSPERDIG)
+                    d = 0.0;
+                else
+                    d = ldexp(d, (int)(lo * BITSPERDIG));
+            }
+        }
     }
     if (BIGNUM_NEGATIVE_P(x)) d = -d;
     return d;
@@ -5310,11 +5447,11 @@ rb_big2dbl(VALUE x)
     double d = big2dbl(x);
 
     if (isinf(d)) {
-	rb_warning("Bignum out of Float range");
-	if (d < 0.0)
-	    d = -HUGE_VAL;
-	else
-	    d = HUGE_VAL;
+        rb_warning("Integer out of Float range");
+        if (d < 0.0)
+            d = -HUGE_VAL;
+        else
+            d = HUGE_VAL;
     }
     return d;
 }
@@ -5371,11 +5508,9 @@ rb_integer_float_cmp(VALUE x, VALUE y)
 
 #if SIZEOF_LONG * CHAR_BIT >= DBL_MANT_DIG /* assume FLT_RADIX == 2 */
 COMPILER_WARNING_PUSH
-#ifdef __has_warning
 #if __has_warning("-Wimplicit-int-float-conversion")
 COMPILER_WARNING_IGNORED(-Wimplicit-int-float-conversion)
 #endif
-#endif
 static const double LONG_MAX_as_double = LONG_MAX;
 COMPILER_WARNING_POP
 #endif
@@ -5386,7 +5521,7 @@ rb_integer_float_eq(VALUE x, VALUE y)
     double yd = RFLOAT_VALUE(y);
     double yi, yf;
 
-    if (isnan(yd) || isinf(yd))
+    if (!isfinite(yd))
         return Qfalse;
     yf = modf(yd, &yi);
     if (yf != 0)
@@ -5394,18 +5529,14 @@ rb_integer_float_eq(VALUE x, VALUE y)
     if (FIXNUM_P(x)) {
 #if SIZEOF_LONG * CHAR_BIT < DBL_MANT_DIG /* assume FLT_RADIX == 2 */
         double xd = (double)FIX2LONG(x);
-        if (xd != yd)
-            return Qfalse;
-        return Qtrue;
+        return RBOOL(xd == yd);
 #else
         long xn, yn;
         if (yi < LONG_MIN || LONG_MAX_as_double <= yi)
             return Qfalse;
         xn = FIX2LONG(x);
         yn = (long)yi;
-        if (xn != yn)
-            return Qfalse;
-        return Qtrue;
+        return RBOOL(xn == yn);
 #endif
     }
     y = rb_dbl2big(yi);
@@ -5417,26 +5548,26 @@ VALUE
 rb_big_cmp(VALUE x, VALUE y)
 {
     if (FIXNUM_P(y)) {
-	x = bigfixize(x);
+        x = bigfixize(x);
         if (FIXNUM_P(x)) {
-	    /* SIGNED_VALUE and Fixnum have same sign-bits, same
-	     * order */
-	    SIGNED_VALUE sx = (SIGNED_VALUE)x, sy = (SIGNED_VALUE)y;
-	    if (sx < sy) return INT2FIX(-1);
-	    return INT2FIX(sx > sy);
+            /* SIGNED_VALUE and Fixnum have same sign-bits, same
+             * order */
+            SIGNED_VALUE sx = (SIGNED_VALUE)x, sy = (SIGNED_VALUE)y;
+            if (sx < sy) return INT2FIX(-1);
+            return INT2FIX(sx > sy);
         }
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
-	if (BIGNUM_SIGN(x) == BIGNUM_SIGN(y)) {
-	    int cmp = bary_cmp(BDIGITS(x), BIGNUM_LEN(x), BDIGITS(y), BIGNUM_LEN(y));
-	    return INT2FIX(BIGNUM_SIGN(x) ? cmp : -cmp);
-	}
+        if (BIGNUM_SIGN(x) == BIGNUM_SIGN(y)) {
+            int cmp = bary_cmp(BDIGITS(x), BIGNUM_LEN(x), BDIGITS(y), BIGNUM_LEN(y));
+            return INT2FIX(BIGNUM_SIGN(x) ? cmp : -cmp);
+        }
     }
     else if (RB_FLOAT_TYPE_P(y)) {
         return rb_integer_float_cmp(x, y);
     }
     else {
-	return rb_num_coerce_cmp(x, y, idCmp);
+        return rb_num_coerce_cmp(x, y, idCmp);
     }
     return INT2FIX(BIGNUM_SIGN(x) ? 1 : -1);
 }
@@ -5455,30 +5586,30 @@ big_op(VALUE x, VALUE y, enum big_op_t op)
     int n;
 
     if (RB_INTEGER_TYPE_P(y)) {
-	rel = rb_big_cmp(x, y);
+        rel = rb_big_cmp(x, y);
     }
     else if (RB_FLOAT_TYPE_P(y)) {
         rel = rb_integer_float_cmp(x, y);
     }
     else {
-	ID id = 0;
-	switch (op) {
-	  case big_op_gt: id = '>'; break;
-	  case big_op_ge: id = idGE; break;
-	  case big_op_lt: id = '<'; break;
-	  case big_op_le: id = idLE; break;
-	}
-	return rb_num_coerce_relop(x, y, id);
+        ID id = 0;
+        switch (op) {
+          case big_op_gt: id = '>'; break;
+          case big_op_ge: id = idGE; break;
+          case big_op_lt: id = '<'; break;
+          case big_op_le: id = idLE; break;
+        }
+        return rb_num_coerce_relop(x, y, id);
     }
 
     if (NIL_P(rel)) return Qfalse;
     n = FIX2INT(rel);
 
     switch (op) {
-	case big_op_gt: return n >  0 ? Qtrue : Qfalse;
-	case big_op_ge: return n >= 0 ? Qtrue : Qfalse;
-	case big_op_lt: return n <  0 ? Qtrue : Qfalse;
-	case big_op_le: return n <= 0 ? Qtrue : Qfalse;
+      case big_op_gt: return RBOOL(n >  0);
+      case big_op_ge: return RBOOL(n >= 0);
+      case big_op_lt: return RBOOL(n <  0);
+      case big_op_le: return RBOOL(n <= 0);
     }
     return Qundef;
 }
@@ -5513,7 +5644,7 @@ rb_big_le(VALUE x, VALUE y)
  *
  *  Returns <code>true</code> only if <i>obj</i> has the same value
  *  as <i>big</i>. Contrast this with Integer#eql?, which requires
- *  <i>obj</i> to be a Integer.
+ *  <i>obj</i> to be an Integer.
  *
  *     68719476736 == 68719476736.0   #=> true
  */
@@ -5522,7 +5653,7 @@ VALUE
 rb_big_eq(VALUE x, VALUE y)
 {
     if (FIXNUM_P(y)) {
-	return bignorm(x) == y ? Qtrue : Qfalse;
+        return RBOOL(bignorm(x) == y);
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
     }
@@ -5530,12 +5661,11 @@ rb_big_eq(VALUE x, VALUE y)
         return rb_integer_float_eq(x, y);
     }
     else {
-	return rb_equal(y, x);
+        return rb_equal(y, x);
     }
     if (BIGNUM_SIGN(x) != BIGNUM_SIGN(y)) return Qfalse;
     if (BIGNUM_LEN(x) != BIGNUM_LEN(y)) return Qfalse;
-    if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,BIGNUM_LEN(y)) != 0) return Qfalse;
-    return Qtrue;
+    return RBOOL(MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,BIGNUM_LEN(y)) == 0);
 }
 
 VALUE
@@ -5544,8 +5674,7 @@ rb_big_eql(VALUE x, VALUE y)
     if (!RB_BIGNUM_TYPE_P(y)) return Qfalse;
     if (BIGNUM_SIGN(x) != BIGNUM_SIGN(y)) return Qfalse;
     if (BIGNUM_LEN(x) != BIGNUM_LEN(y)) return Qfalse;
-    if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,BIGNUM_LEN(y)) != 0) return Qfalse;
-    return Qtrue;
+    return RBOOL(MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,BIGNUM_LEN(y)) == 0);
 }
 
 VALUE
@@ -5636,13 +5765,13 @@ bigsub_int(VALUE x, long y0)
     zds = BDIGITS(z);
 
 #if SIZEOF_BDIGIT >= SIZEOF_LONG
-    assert(xn == zn);
+    RUBY_ASSERT(xn == zn);
     num = (BDIGIT_DBL_SIGNED)xds[0] - y;
     if (xn == 1 && num < 0) {
-	BIGNUM_NEGATE(z);
-	zds[0] = (BDIGIT)-num;
-	RB_GC_GUARD(x);
-	return bignorm(z);
+        BIGNUM_NEGATE(z);
+        zds[0] = (BDIGIT)-num;
+        RB_GC_GUARD(x);
+        return bignorm(z);
     }
     zds[0] = BIGLO(num);
     num = BIGDN(num);
@@ -5654,10 +5783,10 @@ bigsub_int(VALUE x, long y0)
     num = 0;
     for (i=0; i < xn; i++) {
         if (y == 0) goto y_is_zero_x;
-	num += (BDIGIT_DBL_SIGNED)xds[i] - BIGLO(y);
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
-	y = BIGDN(y);
+        num += (BDIGIT_DBL_SIGNED)xds[i] - BIGLO(y);
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
+        y = BIGDN(y);
     }
     for (; i < zn; i++) {
         if (y == 0) goto y_is_zero_z;
@@ -5672,9 +5801,9 @@ bigsub_int(VALUE x, long y0)
     for (; i < xn; i++) {
       y_is_zero_x:
         if (num == 0) goto num_is_zero_x;
-	num += xds[i];
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        num += xds[i];
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
 #if SIZEOF_BDIGIT < SIZEOF_LONG
     for (; i < zn; i++) {
@@ -5688,7 +5817,7 @@ bigsub_int(VALUE x, long y0)
 
     for (; i < xn; i++) {
       num_is_zero_x:
-	zds[i] = xds[i];
+        zds[i] = xds[i];
     }
 #if SIZEOF_BDIGIT < SIZEOF_LONG
     for (; i < zn; i++) {
@@ -5699,10 +5828,10 @@ bigsub_int(VALUE x, long y0)
     goto finish;
 
   finish:
-    assert(num == 0 || num == -1);
+    RUBY_ASSERT(num == 0 || num == -1);
     if (num < 0) {
         get2comp(z);
-	BIGNUM_NEGATE(z);
+        BIGNUM_NEGATE(z);
     }
     RB_GC_GUARD(x);
     return bignorm(z);
@@ -5745,17 +5874,17 @@ bigadd_int(VALUE x, long y)
     num = 0;
     for (i=0; i < xn; i++) {
         if (y == 0) goto y_is_zero_x;
-	num += (BDIGIT_DBL)xds[i] + BIGLO(y);
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
-	y = BIGDN(y);
+        num += (BDIGIT_DBL)xds[i] + BIGLO(y);
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
+        y = BIGDN(y);
     }
     for (; i < zn; i++) {
         if (y == 0) goto y_is_zero_z;
-	num += BIGLO(y);
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
-	y = BIGDN(y);
+        num += BIGLO(y);
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
+        y = BIGDN(y);
     }
     goto finish;
 
@@ -5764,25 +5893,25 @@ bigadd_int(VALUE x, long y)
     for (;i < xn; i++) {
       y_is_zero_x:
         if (num == 0) goto num_is_zero_x;
-	num += (BDIGIT_DBL)xds[i];
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        num += (BDIGIT_DBL)xds[i];
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
     for (; i < zn; i++) {
       y_is_zero_z:
         if (num == 0) goto num_is_zero_z;
-	zds[i] = BIGLO(num);
-	num = BIGDN(num);
+        zds[i] = BIGLO(num);
+        num = BIGDN(num);
     }
     goto finish;
 
     for (;i < xn; i++) {
       num_is_zero_x:
-	zds[i] = xds[i];
+        zds[i] = xds[i];
     }
     for (; i < zn; i++) {
       num_is_zero_z:
-	zds[i] = 0;
+        zds[i] = 0;
     }
     goto finish;
 
@@ -5799,15 +5928,15 @@ bigadd(VALUE x, VALUE y, int sign)
 
     sign = (sign == BIGNUM_SIGN(y));
     if (BIGNUM_SIGN(x) != sign) {
-	if (sign) return bigsub(y, x);
-	return bigsub(x, y);
+        if (sign) return bigsub(y, x);
+        return bigsub(x, y);
     }
 
     if (BIGNUM_LEN(x) > BIGNUM_LEN(y)) {
-	len = BIGNUM_LEN(x) + 1;
+        len = BIGNUM_LEN(x) + 1;
     }
     else {
-	len = BIGNUM_LEN(y) + 1;
+        len = BIGNUM_LEN(y) + 1;
     }
     z = bignew(len, sign);
 
@@ -5824,26 +5953,26 @@ rb_big_plus(VALUE x, VALUE y)
     long n;
 
     if (FIXNUM_P(y)) {
-	n = FIX2LONG(y);
-	if ((n > 0) != BIGNUM_SIGN(x)) {
-	    if (n < 0) {
-		n = -n;
-	    }
-	    return bigsub_int(x, n);
-	}
-	if (n < 0) {
-	    n = -n;
-	}
-	return bigadd_int(x, n);
+        n = FIX2LONG(y);
+        if ((n > 0) != BIGNUM_SIGN(x)) {
+            if (n < 0) {
+                n = -n;
+            }
+            return bigsub_int(x, n);
+        }
+        if (n < 0) {
+            n = -n;
+        }
+        return bigadd_int(x, n);
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
-	return bignorm(bigadd(x, y, 1));
+        return bignorm(bigadd(x, y, 1));
     }
     else if (RB_FLOAT_TYPE_P(y)) {
-	return DBL2NUM(rb_big2dbl(x) + RFLOAT_VALUE(y));
+        return DBL2NUM(rb_big2dbl(x) + RFLOAT_VALUE(y));
     }
     else {
-	return rb_num_coerce_bin(x, y, '+');
+        return rb_num_coerce_bin(x, y, '+');
     }
 }
 
@@ -5853,26 +5982,26 @@ rb_big_minus(VALUE x, VALUE y)
     long n;
 
     if (FIXNUM_P(y)) {
-	n = FIX2LONG(y);
-	if ((n > 0) != BIGNUM_SIGN(x)) {
-	    if (n < 0) {
-		n = -n;
-	    }
-	    return bigadd_int(x, n);
-	}
-	if (n < 0) {
-	    n = -n;
-	}
-	return bigsub_int(x, n);
+        n = FIX2LONG(y);
+        if ((n > 0) != BIGNUM_SIGN(x)) {
+            if (n < 0) {
+                n = -n;
+            }
+            return bigadd_int(x, n);
+        }
+        if (n < 0) {
+            n = -n;
+        }
+        return bigsub_int(x, n);
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
-	return bignorm(bigadd(x, y, 0));
+        return bignorm(bigadd(x, y, 0));
     }
     else if (RB_FLOAT_TYPE_P(y)) {
-	return DBL2NUM(rb_big2dbl(x) - RFLOAT_VALUE(y));
+        return DBL2NUM(rb_big2dbl(x) - RFLOAT_VALUE(y));
     }
     else {
-	return rb_num_coerce_bin(x, y, '-');
+        return rb_num_coerce_bin(x, y, '-');
     }
 }
 
@@ -5884,6 +6013,8 @@ bigsq(VALUE x)
     BDIGIT *xds, *zds;
 
     xn = BIGNUM_LEN(x);
+    if (MUL_OVERFLOW_LONG_P(2, xn))
+        rb_raise(rb_eArgError, "square overflow");
     zn = 2 * xn;
 
     z = bignew(zn, 1);
@@ -5912,6 +6043,8 @@ bigmul0(VALUE x, VALUE y)
 
     xn = BIGNUM_LEN(x);
     yn = BIGNUM_LEN(y);
+    if (ADD_OVERFLOW_LONG_P(xn, yn))
+        rb_raise(rb_eArgError, "multiplication overflow");
     zn = xn + yn;
 
     z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
@@ -5931,15 +6064,15 @@ VALUE
 rb_big_mul(VALUE x, VALUE y)
 {
     if (FIXNUM_P(y)) {
-	y = rb_int2big(FIX2LONG(y));
+        y = rb_int2big(FIX2LONG(y));
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
     }
     else if (RB_FLOAT_TYPE_P(y)) {
-	return DBL2NUM(rb_big2dbl(x) * RFLOAT_VALUE(y));
+        return DBL2NUM(rb_big2dbl(x) * RFLOAT_VALUE(y));
     }
     else {
-	return rb_num_coerce_bin(x, y, '*');
+        return rb_num_coerce_bin(x, y, '*');
     }
 
     return bignorm(bigmul0(x, y));
@@ -5966,21 +6099,21 @@ bigdivrem(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp)
     BARY_TRUNC(xds, xn);
 
     if (xn < yn || (xn == yn && xds[xn - 1] < yds[yn - 1])) {
-	if (divp) *divp = rb_int2big(0);
-	if (modp) *modp = x;
-	return Qnil;
+        if (divp) *divp = rb_int2big(0);
+        if (modp) *modp = x;
+        return Qnil;
     }
     if (yn == 1) {
-	dd = yds[0];
-	z = bignew(xn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
-	zds = BDIGITS(z);
+        dd = yds[0];
+        z = bignew(xn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
+        zds = BDIGITS(z);
         dd = bigdivrem_single(zds, xds, xn, dd);
-	if (modp) {
-	    *modp = rb_uint2big((uintptr_t)dd);
-	    BIGNUM_SET_SIGN(*modp, BIGNUM_SIGN(x));
-	}
-	if (divp) *divp = z;
-	return Qnil;
+        if (modp) {
+            *modp = rb_uint2big((uintptr_t)dd);
+            BIGNUM_SET_SIGN(*modp, BIGNUM_SIGN(x));
+        }
+        if (divp) *divp = z;
+        return Qnil;
     }
     if (xn == 2 && yn == 2) {
         BDIGIT_DBL x0 = bary2bdigitdbl(xds, 2);
@@ -6045,11 +6178,11 @@ bigdivmod(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp)
 
     bigdivrem(x, y, divp, &mod);
     if (BIGNUM_SIGN(x) != BIGNUM_SIGN(y) && !BIGZEROP(mod)) {
-	if (divp) *divp = bigadd(*divp, rb_int2big(1), 0);
-	if (modp) *modp = bigadd(mod, y, 1);
+        if (divp) *divp = bigadd(*divp, rb_int2big(1), 0);
+        if (modp) *modp = bigadd(mod, y, 1);
     }
     else if (modp) {
-	*modp = mod;
+        *modp = mod;
     }
 }
 
@@ -6060,25 +6193,25 @@ rb_big_divide(VALUE x, VALUE y, ID op)
     VALUE z;
 
     if (FIXNUM_P(y)) {
-	y = rb_int2big(FIX2LONG(y));
+        y = rb_int2big(FIX2LONG(y));
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
     }
     else if (RB_FLOAT_TYPE_P(y)) {
-	if (op == '/') {
+        if (op == '/') {
             double dx = rb_big2dbl(x);
             return rb_flo_div_flo(DBL2NUM(dx), y);
-	}
-	else {
+        }
+        else {
             VALUE v;
-	    double dy = RFLOAT_VALUE(y);
-	    if (dy == 0.0) rb_num_zerodiv();
+            double dy = RFLOAT_VALUE(y);
+            if (dy == 0.0) rb_num_zerodiv();
             v = rb_big_divide(x, y, '/');
             return rb_dbl2big(RFLOAT_VALUE(v));
-	}
+        }
     }
     else {
-	return rb_num_coerce_bin(x, y, op);
+        return rb_num_coerce_bin(x, y, op);
     }
     bigdivmod(x, y, &z, 0);
 
@@ -6103,10 +6236,10 @@ rb_big_modulo(VALUE x, VALUE y)
     VALUE z;
 
     if (FIXNUM_P(y)) {
-	y = rb_int2big(FIX2LONG(y));
+        y = rb_int2big(FIX2LONG(y));
     }
     else if (!RB_BIGNUM_TYPE_P(y)) {
-	return rb_num_coerce_bin(x, y, '%');
+        return rb_num_coerce_bin(x, y, '%');
     }
     bigdivmod(x, y, 0, &z);
 
@@ -6119,10 +6252,10 @@ rb_big_remainder(VALUE x, VALUE y)
     VALUE z;
 
     if (FIXNUM_P(y)) {
-	y = rb_int2big(FIX2LONG(y));
+        y = rb_int2big(FIX2LONG(y));
     }
     else if (!RB_BIGNUM_TYPE_P(y)) {
-	return rb_num_coerce_bin(x, y, rb_intern("remainder"));
+        return rb_num_coerce_bin(x, y, rb_intern("remainder"));
     }
     bigdivrem(x, y, 0, &z);
 
@@ -6135,7 +6268,7 @@ rb_big_divmod(VALUE x, VALUE y)
     VALUE div, mod;
 
     if (FIXNUM_P(y)) {
-	y = rb_int2big(FIX2LONG(y));
+        y = rb_int2big(FIX2LONG(y));
     }
     else if (!RB_BIGNUM_TYPE_P(y)) {
         return rb_num_coerce_bin(x, y, idDivmod);
@@ -6149,9 +6282,9 @@ static VALUE
 big_shift(VALUE x, long n)
 {
     if (n < 0)
-	return big_lshift(x, 1+(unsigned long)(-(n+1)));
+        return big_lshift(x, 1+(unsigned long)(-(n+1)));
     else if (n > 0)
-	return big_rshift(x, (unsigned long)n);
+        return big_rshift(x, (unsigned long)n);
     return x;
 }
 
@@ -6175,9 +6308,9 @@ big_fdiv(VALUE x, VALUE y, long ey)
     l = ex - ey;
 #if SIZEOF_LONG > SIZEOF_INT
     {
-	/* Visual C++ can't be here */
-	if (l > INT_MAX) return HUGE_VAL;
-	if (l < INT_MIN) return 0.0;
+        /* Visual C++ can't be here */
+        if (l > INT_MAX) return HUGE_VAL;
+        if (l < INT_MIN) return 0.0;
     }
 #endif
     return ldexp(big2dbl(z), (int)l);
@@ -6211,19 +6344,19 @@ rb_big_fdiv_double(VALUE x, VALUE y)
 
     dx = big2dbl(x);
     if (FIXNUM_P(y)) {
-	dy = (double)FIX2LONG(y);
-	if (isinf(dx))
-	    return big_fdiv_int(x, rb_int2big(FIX2LONG(y)));
+        dy = (double)FIX2LONG(y);
+        if (isinf(dx))
+            return big_fdiv_int(x, rb_int2big(FIX2LONG(y)));
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
-	return big_fdiv_int(x, y);
+        return big_fdiv_int(x, y);
     }
     else if (RB_FLOAT_TYPE_P(y)) {
-	dy = RFLOAT_VALUE(y);
-	if (isnan(dy))
-	    return dy;
-	if (isinf(dx))
-	    return big_fdiv_float(x, y);
+        dy = RFLOAT_VALUE(y);
+        if (isnan(dy))
+            return dy;
+        if (isinf(dx))
+            return big_fdiv_float(x, y);
     }
     else {
         return NUM2DBL(rb_num_coerce_bin(x, y, idFdiv));
@@ -6248,53 +6381,56 @@ rb_big_pow(VALUE x, VALUE y)
     if (y == INT2FIX(0)) return INT2FIX(1);
     if (y == INT2FIX(1)) return x;
     if (RB_FLOAT_TYPE_P(y)) {
-	d = RFLOAT_VALUE(y);
-	if ((BIGNUM_NEGATIVE_P(x) && !BIGZEROP(x))) {
+        d = RFLOAT_VALUE(y);
+        if ((BIGNUM_NEGATIVE_P(x) && !BIGZEROP(x))) {
             return rb_dbl_complex_new_polar_pi(pow(-rb_big2dbl(x), d), d);
-	}
+        }
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
-	y = bignorm(y);
-	if (FIXNUM_P(y))
-	    goto again;
-	rb_warn("in a**b, b may be too big");
-	d = rb_big2dbl(y);
+        y = bignorm(y);
+        if (FIXNUM_P(y))
+            goto again;
+        rb_raise(rb_eArgError, "exponent is too large");
     }
     else if (FIXNUM_P(y)) {
-	yy = FIX2LONG(y);
+        yy = FIX2LONG(y);
 
         if (yy < 0) {
-            x = rb_big_pow(x, INT2NUM(-yy));
+            x = rb_big_pow(x, LONG2NUM(-yy));
             if (RB_INTEGER_TYPE_P(x))
                 return rb_rational_raw(INT2FIX(1), x);
             else
                 return DBL2NUM(1.0 / NUM2DBL(x));
         }
-	else {
-	    VALUE z = 0;
-	    SIGNED_VALUE mask;
+        else {
+            VALUE z = 0;
+            SIGNED_VALUE mask;
             const size_t xbits = rb_absint_numwords(x, 1, NULL);
-	    const size_t BIGLEN_LIMIT = 32*1024*1024;
+#if SIZEOF_SIZE_T == 4
+            const size_t BIGLEN_LIMIT = 1ULL << 31; // 2 GB
+#else // SIZEOF_SIZE_T == 8
+            const size_t BIGLEN_LIMIT = 1ULL << 34; // 16 GB
+#endif
 
-	    if (xbits == (size_t)-1 ||
+            if (xbits == (size_t)-1 ||
                 (xbits > BIGLEN_LIMIT) ||
+                MUL_OVERFLOW_LONG_P(yy, xbits) ||
                 (xbits * yy > BIGLEN_LIMIT)) {
-		rb_warn("in a**b, b may be too big");
-		d = (double)yy;
-	    }
-	    else {
-		for (mask = FIXNUM_MAX + 1; mask; mask >>= 1) {
-		    if (z) z = bigsq(z);
-		    if (yy & mask) {
-			z = z ? bigtrunc(bigmul0(z, x)) : x;
-		    }
-		}
-		return bignorm(z);
-	    }
-	}
+                rb_raise(rb_eArgError, "exponent is too large");
+            }
+            else {
+                for (mask = FIXNUM_MAX + 1; mask; mask >>= 1) {
+                    if (z) z = bigsq(z);
+                    if (yy & mask) {
+                        z = z ? bigtrunc(bigmul0(z, x)) : x;
+                    }
+                }
+                return bignorm(z);
+            }
+        }
     }
     else {
-	return rb_num_coerce_bin(x, y, idPow);
+        return rb_num_coerce_bin(x, y, idPow);
     }
     return DBL2NUM(pow(rb_big2dbl(x), d));
 }
@@ -6309,13 +6445,13 @@ bigand_int(VALUE x, long xn, BDIGIT hibitsx, long y)
     BDIGIT hibitsy;
 
     if (y == 0) return INT2FIX(0);
-    if (xn == 0) return hibitsx ? LONG2NUM(y) : 0;
+    if (xn == 0) return hibitsx ? LONG2NUM(y) : INT2FIX(0);
     hibitsy = 0 <= y ? 0 : BDIGMAX;
     xds = BDIGITS(x);
 #if SIZEOF_BDIGIT >= SIZEOF_LONG
     if (!hibitsy) {
-	y &= xds[0];
-	return LONG2NUM(y);
+        y &= xds[0];
+        return LONG2NUM(y);
     }
 #endif
 
@@ -6344,10 +6480,10 @@ bigand_int(VALUE x, long xn, BDIGIT hibitsx, long y)
     }
 #endif
     for (;i < xn; i++) {
-	zds[i] = xds[i] & hibitsy;
+        zds[i] = xds[i] & hibitsy;
     }
     for (;i < zn; i++) {
-	zds[i] = hibitsx & hibitsy;
+        zds[i] = hibitsx & hibitsy;
     }
     twocomp2abs_bang(z, hibitsx && hibitsy);
     RB_GC_GUARD(x);
@@ -6367,12 +6503,12 @@ rb_big_and(VALUE x, VALUE y)
     long tmpn;
 
     if (!RB_INTEGER_TYPE_P(y)) {
-	return rb_num_coerce_bit(x, y, '&');
+        return rb_num_coerce_bit(x, y, '&');
     }
 
     hibitsx = abs2twocomp(&x, &xn);
     if (FIXNUM_P(y)) {
-	return bigand_int(x, xn, hibitsx, FIX2LONG(y));
+        return bigand_int(x, xn, hibitsx, FIX2LONG(y));
     }
     hibitsy = abs2twocomp(&y, &yn);
     if (xn > yn) {
@@ -6394,10 +6530,10 @@ rb_big_and(VALUE x, VALUE y)
     zds = BDIGITS(z);
 
     for (i=0; i<n1; i++) {
-	zds[i] = ds1[i] & ds2[i];
+        zds[i] = ds1[i] & ds2[i];
     }
     for (; i<n2; i++) {
-	zds[i] = hibits1 & ds2[i];
+        zds[i] = hibits1 & ds2[i];
     }
     twocomp2abs_bang(z, hibits1 && hibits2);
     RB_GC_GUARD(x);
@@ -6486,12 +6622,12 @@ rb_big_or(VALUE x, VALUE y)
     long tmpn;
 
     if (!RB_INTEGER_TYPE_P(y)) {
-	return rb_num_coerce_bit(x, y, '|');
+        return rb_num_coerce_bit(x, y, '|');
     }
 
     hibitsx = abs2twocomp(&x, &xn);
     if (FIXNUM_P(y)) {
-	return bigor_int(x, xn, hibitsx, FIX2LONG(y));
+        return bigor_int(x, xn, hibitsx, FIX2LONG(y));
     }
     hibitsy = abs2twocomp(&y, &yn);
     if (xn > yn) {
@@ -6513,10 +6649,10 @@ rb_big_or(VALUE x, VALUE y)
     zds = BDIGITS(z);
 
     for (i=0; i<n1; i++) {
-	zds[i] = ds1[i] | ds2[i];
+        zds[i] = ds1[i] | ds2[i];
     }
     for (; i<n2; i++) {
-	zds[i] = hibits1 | ds2[i];
+        zds[i] = hibits1 | ds2[i];
     }
     twocomp2abs_bang(z, hibits1 || hibits2);
     RB_GC_GUARD(x);
@@ -6580,12 +6716,12 @@ rb_big_xor(VALUE x, VALUE y)
     long tmpn;
 
     if (!RB_INTEGER_TYPE_P(y)) {
-	return rb_num_coerce_bit(x, y, '^');
+        return rb_num_coerce_bit(x, y, '^');
     }
 
     hibitsx = abs2twocomp(&x, &xn);
     if (FIXNUM_P(y)) {
-	return bigxor_int(x, xn, hibitsx, FIX2LONG(y));
+        return bigxor_int(x, xn, hibitsx, FIX2LONG(y));
     }
     hibitsy = abs2twocomp(&y, &yn);
     if (xn > yn) {
@@ -6604,10 +6740,10 @@ rb_big_xor(VALUE x, VALUE y)
     zds = BDIGITS(z);
 
     for (i=0; i<n1; i++) {
-	zds[i] = ds1[i] ^ ds2[i];
+        zds[i] = ds1[i] ^ ds2[i];
     }
     for (; i<n2; i++) {
-	zds[i] = hibitsx ^ ds2[i];
+        zds[i] = hibitsx ^ ds2[i];
     }
     twocomp2abs_bang(z, (hibits1 ^ hibits2) != 0);
     RB_GC_GUARD(x);
@@ -6623,25 +6759,25 @@ rb_big_lshift(VALUE x, VALUE y)
     int shift_numbits;
 
     for (;;) {
-	if (FIXNUM_P(y)) {
-	    long l = FIX2LONG(y);
+        if (FIXNUM_P(y)) {
+            long l = FIX2LONG(y);
             unsigned long shift;
-	    if (0 <= l) {
-		lshift_p = 1;
+            if (0 <= l) {
+                lshift_p = 1;
                 shift = l;
             }
             else {
-		lshift_p = 0;
-		shift = 1+(unsigned long)(-(l+1));
-	    }
+                lshift_p = 0;
+                shift = 1+(unsigned long)(-(l+1));
+            }
             shift_numbits = (int)(shift & (BITSPERDIG-1));
             shift_numdigits = shift >> bit_length(BITSPERDIG-1);
             return bignorm(big_shift3(x, lshift_p, shift_numdigits, shift_numbits));
-	}
-	else if (RB_BIGNUM_TYPE_P(y)) {
+        }
+        else if (RB_BIGNUM_TYPE_P(y)) {
             return bignorm(big_shift2(x, 1, y));
-	}
-	y = rb_to_int(y);
+        }
+        y = rb_to_int(y);
     }
 }
 
@@ -6653,8 +6789,8 @@ rb_big_rshift(VALUE x, VALUE y)
     int shift_numbits;
 
     for (;;) {
-	if (FIXNUM_P(y)) {
-	    long l = FIX2LONG(y);
+        if (FIXNUM_P(y)) {
+            long l = FIX2LONG(y);
             unsigned long shift;
             if (0 <= l) {
                 lshift_p = 0;
@@ -6662,16 +6798,16 @@ rb_big_rshift(VALUE x, VALUE y)
             }
             else {
                 lshift_p = 1;
-		shift = 1+(unsigned long)(-(l+1));
-	    }
+                shift = 1+(unsigned long)(-(l+1));
+            }
             shift_numbits = (int)(shift & (BITSPERDIG-1));
             shift_numdigits = shift >> bit_length(BITSPERDIG-1);
             return bignorm(big_shift3(x, lshift_p, shift_numdigits, shift_numbits));
-	}
-	else if (RB_BIGNUM_TYPE_P(y)) {
+        }
+        else if (RB_BIGNUM_TYPE_P(y)) {
             return bignorm(big_shift2(x, 0, y));
-	}
-	y = rb_to_int(y);
+        }
+        y = rb_to_int(y);
     }
 }
 
@@ -6685,29 +6821,29 @@ rb_big_aref(VALUE x, VALUE y)
     BDIGIT bit;
 
     if (RB_BIGNUM_TYPE_P(y)) {
-	if (BIGNUM_NEGATIVE_P(y))
-	    return INT2FIX(0);
-	bigtrunc(y);
-	if (BIGSIZE(y) > sizeof(size_t)) {
-	  out_of_range:
-	    return BIGNUM_SIGN(x) ? INT2FIX(0) : INT2FIX(1);
-	}
+        if (BIGNUM_NEGATIVE_P(y))
+            return INT2FIX(0);
+        bigtrunc(y);
+        if (BIGSIZE(y) > sizeof(size_t)) {
+            return BIGNUM_SIGN(x) ? INT2FIX(0) : INT2FIX(1);
+        }
 #if SIZEOF_SIZE_T <= SIZEOF_LONG
-	shift = big2ulong(y, "long");
+        shift = big2ulong(y, "long");
 #else
-	shift = big2ull(y, "long long");
+        shift = big2ull(y, "long long");
 #endif
     }
     else {
-	l = NUM2LONG(y);
-	if (l < 0) return INT2FIX(0);
-	shift = (size_t)l;
+        l = NUM2LONG(y);
+        if (l < 0) return INT2FIX(0);
+        shift = (size_t)l;
     }
     s1 = shift/BITSPERDIG;
     s2 = shift%BITSPERDIG;
     bit = (BDIGIT)1 << s2;
 
-    if (s1 >= BIGNUM_LEN(x)) goto out_of_range;
+    if (s1 >= BIGNUM_LEN(x))
+        return BIGNUM_SIGN(x) ? INT2FIX(0) : INT2FIX(1);
 
     xds = BDIGITS(x);
     if (BIGNUM_POSITIVE_P(x))
@@ -6721,6 +6857,73 @@ rb_big_aref(VALUE x, VALUE y)
 }
 
 VALUE
+rb_big_aref2(VALUE x, VALUE beg, VALUE len)
+{
+    BDIGIT *xds, *vds;
+    VALUE v;
+    size_t copy_begin, xn, shift;
+    ssize_t begin, length, end;
+    bool negative_add_one;
+
+    beg = rb_to_int(beg);
+    len = rb_to_int(len);
+    length = NUM2SSIZET(len);
+    begin = NUM2SSIZET(beg);
+    end = NUM2SSIZET(rb_int_plus(beg, len));
+    shift = begin < 0 ? -begin : 0;
+    xn = BIGNUM_LEN(x);
+    xds = BDIGITS(x);
+
+    if (length < 0) return rb_big_rshift(x, beg);
+    if (length == 0 || end <= 0) return INT2FIX(0);
+    if (begin < 0) begin = 0;
+
+    if ((size_t)(end - 1) / BITSPERDIG >= xn) {
+        /* end > xn * BITSPERDIG */
+        end = xn * BITSPERDIG;
+    }
+
+    if ((size_t)begin / BITSPERDIG < xn) {
+        /* begin < xn * BITSPERDIG */
+        size_t shift_bits, copy_end;
+        copy_begin = begin / BITSPERDIG;
+        shift_bits = begin % BITSPERDIG;
+        copy_end = (end - 1) / BITSPERDIG + 1;
+        v = bignew(copy_end - copy_begin, 1);
+        vds = BDIGITS(v);
+        MEMCPY(vds, xds + copy_begin, BDIGIT, copy_end - copy_begin);
+        negative_add_one = (vds[0] & ((1 << shift_bits) - 1)) == 0;
+        v = bignorm(v);
+        if (shift_bits) v = rb_int_rshift(v, SIZET2NUM(shift_bits));
+    }
+    else {
+        /* Out of range */
+        v = INT2FIX(0);
+        negative_add_one = false;
+        copy_begin = begin = end = 0;
+    }
+
+    if (BIGNUM_NEGATIVE_P(x)) {
+        size_t mask_size = length - shift;
+        VALUE mask = rb_int_minus(rb_int_lshift(INT2FIX(1), SIZET2NUM(mask_size)), INT2FIX(1));
+        v = rb_int_xor(v, mask);
+        for (size_t i = 0; negative_add_one && i < copy_begin; i++) {
+            if (xds[i]) negative_add_one = false;
+        }
+        if (negative_add_one) v = rb_int_plus(v, INT2FIX(1));
+        v = rb_int_and(v, mask);
+    }
+    else {
+        size_t mask_size = (size_t)end - begin;
+        VALUE mask = rb_int_minus(rb_int_lshift(INT2FIX(1), SIZET2NUM(mask_size)), INT2FIX(1));
+        v = rb_int_and(v, mask);
+    }
+    RB_GC_GUARD(x);
+    if (shift) v = rb_int_lshift(v, SSIZET2NUM(shift));
+    return v;
+}
+
+VALUE
 rb_big_hash(VALUE x)
 {
     st_index_t hash;
@@ -6731,14 +6934,15 @@ rb_big_hash(VALUE x)
 
 /*
  * call-seq:
- *   big.coerce(numeric)  ->  array
+ *   int.coerce(numeric)  ->  array
  *
- * Returns an array with both a +numeric+ and a +big+ represented as Bignum
- * objects.
+ * Returns an array with both a +numeric+ and a +int+ represented as
+ * Integer objects or Float objects.
  *
- * This is achieved by converting +numeric+ to a Bignum.
+ * This is achieved by converting +numeric+ to an Integer or a Float.
  *
- * A TypeError is raised if the +numeric+ is not a Fixnum or Bignum type.
+ * A TypeError is raised if the +numeric+ is not an Integer or a Float
+ * type.
  *
  *     (0x3FFFFFFFFFFFFFFF+1).coerce(42)   #=> [42, 4611686018427387904]
  */
@@ -6760,8 +6964,8 @@ VALUE
 rb_big_abs(VALUE x)
 {
     if (BIGNUM_NEGATIVE_P(x)) {
-	x = rb_big_clone(x);
-	BIGNUM_SET_POSITIVE_SIGN(x);
+        x = rb_big_clone(x);
+        BIGNUM_SET_POSITIVE_SIGN(x);
     }
     return x;
 }
@@ -6828,17 +7032,14 @@ rb_big_bit_length(VALUE big)
 VALUE
 rb_big_odd_p(VALUE num)
 {
-    if (BIGNUM_LEN(num) != 0 && BDIGITS(num)[0] & 1) {
-	return Qtrue;
-    }
-    return Qfalse;
+    return RBOOL(BIGNUM_LEN(num) != 0 && BDIGITS(num)[0] & 1);
 }
 
 VALUE
 rb_big_even_p(VALUE num)
 {
     if (BIGNUM_LEN(num) != 0 && BDIGITS(num)[0] & 1) {
-	return Qfalse;
+        return Qfalse;
     }
     return Qtrue;
 }
@@ -6856,103 +7057,50 @@ BDIGIT rb_bdigit_dbl_isqrt(BDIGIT_DBL);
 # define BDIGIT_DBL_TO_DOUBLE(n) (double)(n)
 #endif
 
-static BDIGIT *
-estimate_initial_sqrt(VALUE *xp, const size_t xn, const BDIGIT *nds, size_t len)
-{
-    enum {dbl_per_bdig = roomof(DBL_MANT_DIG,BITSPERDIG)};
-    const int zbits = nlz(nds[len-1]);
-    VALUE x = *xp = bignew_1(0, xn, 1); /* division may release the GVL */
-    BDIGIT *xds = BDIGITS(x);
-    BDIGIT_DBL d = bary2bdigitdbl(nds+len-dbl_per_bdig, dbl_per_bdig);
-    BDIGIT lowbits = 1;
-    int rshift = (int)((BITSPERDIG*2-zbits+(len&BITSPERDIG&1) - DBL_MANT_DIG + 1) & ~1);
-    double f;
-
-    if (rshift > 0) {
-	lowbits = (BDIGIT)d & ~(~(BDIGIT)1U << rshift);
-	d >>= rshift;
-    }
-    else if (rshift < 0) {
-	d <<= -rshift;
-	d |= nds[len-dbl_per_bdig-1] >> (BITSPERDIG+rshift);
-    }
-    f = sqrt(BDIGIT_DBL_TO_DOUBLE(d));
-    d = (BDIGIT_DBL)ceil(f);
-    if (BDIGIT_DBL_TO_DOUBLE(d) == f) {
-	if (lowbits || (lowbits = !bary_zero_p(nds, len-dbl_per_bdig)))
-	    ++d;
-    }
-    else {
-	lowbits = 1;
-    }
-    rshift /= 2;
-    rshift += (2-(len&1))*BITSPERDIG/2;
-    if (rshift >= 0) {
-	d <<= rshift;
-    }
-    BDIGITS_ZERO(xds, xn-2);
-    bdigitdbl2bary(&xds[xn-2], 2, d);
-
-    if (!lowbits) return NULL; /* special case, exact result */
-    return xds;
-}
-
 VALUE
 rb_big_isqrt(VALUE n)
 {
     BDIGIT *nds = BDIGITS(n);
     size_t len = BIGNUM_LEN(n);
-    size_t xn = (len+1) / 2;
-    VALUE x;
-    BDIGIT *xds;
 
     if (len <= 2) {
-	BDIGIT sq = rb_bdigit_dbl_isqrt(bary2bdigitdbl(nds, len));
+        BDIGIT sq = rb_bdigit_dbl_isqrt(bary2bdigitdbl(nds, len));
 #if SIZEOF_BDIGIT > SIZEOF_LONG
-	return ULL2NUM(sq);
+        return ULL2NUM(sq);
 #else
-	return ULONG2NUM(sq);
+        return ULONG2NUM(sq);
 #endif
     }
-    else if ((xds = estimate_initial_sqrt(&x, xn, nds, len)) != 0) {
-	size_t tn = xn + BIGDIVREM_EXTRA_WORDS;
-	VALUE t = bignew_1(0, tn, 1);
-	BDIGIT *tds = BDIGITS(t);
-	tn = BIGNUM_LEN(t);
-
-	/* t = n/x */
-	while (bary_divmod_branch(tds, tn, NULL, 0, nds, len, xds, xn),
-	       bary_cmp(tds, tn, xds, xn) < 0) {
-	    int carry;
-	    BARY_TRUNC(tds, tn);
-	    /* x = (x+t)/2 */
-	    carry = bary_add(xds, xn, xds, xn, tds, tn);
-	    bary_small_rshift(xds, xds, xn, 1, carry);
-	    tn = BIGNUM_LEN(t);
-	}
-	rb_big_realloc(t, 0);
-	rb_gc_force_recycle(t);
-    }
-    RBASIC_SET_CLASS_RAW(x, rb_cInteger);
-    return x;
+    else {
+        size_t shift = FIX2LONG(rb_big_bit_length(n)) / 4;
+        VALUE n2 = rb_int_rshift(n, SIZET2NUM(2 * shift));
+        VALUE x = FIXNUM_P(n2) ? LONG2FIX(rb_ulong_isqrt(FIX2ULONG(n2))) : rb_big_isqrt(n2);
+        /* x = (x+n/x)/2 */
+        x = rb_int_plus(rb_int_lshift(x, SIZET2NUM(shift - 1)), rb_int_idiv(rb_int_rshift(n, SIZET2NUM(shift + 1)), x));
+        VALUE xx = rb_int_mul(x, x);
+        while (rb_int_gt(xx, n)) {
+            xx = rb_int_minus(xx, rb_int_minus(rb_int_plus(x, x), INT2FIX(1)));
+            x = rb_int_minus(x, INT2FIX(1));
+        }
+        return x;
+    }
 }
 
-#ifdef USE_GMP
+#if USE_GMP
 static void
 bary_powm_gmp(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, const BDIGIT *mds, size_t mn)
 {
-    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
     mpz_t z, x, y, m;
     size_t count;
     mpz_init(x);
     mpz_init(y);
     mpz_init(m);
     mpz_init(z);
-    mpz_import(x, xn, -1, sizeof(BDIGIT), 0, nails, xds);
-    mpz_import(y, yn, -1, sizeof(BDIGIT), 0, nails, yds);
-    mpz_import(m, mn, -1, sizeof(BDIGIT), 0, nails, mds);
+    bdigits_to_mpz(x, xds, xn);
+    bdigits_to_mpz(y, yds, yn);
+    bdigits_to_mpz(m, mds, mn);
     mpz_powm(z, x, y, m);
-    mpz_export(zds, &count, -1, sizeof(BDIGIT), 0, nails, z);
+    bdigits_from_mpz(z, zds, &count);
     BDIGITS_ZERO(zds+count, zn-count);
     mpz_clear(x);
     mpz_clear(y);
@@ -6964,7 +7112,7 @@ bary_powm_gmp(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT
 static VALUE
 int_pow_tmp3(VALUE x, VALUE y, VALUE m, int nega_flg)
 {
-#ifdef USE_GMP
+#if USE_GMP
     VALUE z;
     size_t xn, yn, mn, zn;
 
@@ -6974,14 +7122,14 @@ int_pow_tmp3(VALUE x, VALUE y, VALUE m, int nega_flg)
     if (FIXNUM_P(y)) {
        y = rb_int2big(FIX2LONG(y));
     }
-    assert(RB_BIGNUM_TYPE_P(m));
+    RUBY_ASSERT(RB_BIGNUM_TYPE_P(m));
     xn = BIGNUM_LEN(x);
     yn = BIGNUM_LEN(y);
     mn = BIGNUM_LEN(m);
     zn = mn;
     z = bignew(zn, 1);
     bary_powm_gmp(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, BDIGITS(m), mn);
-    if (nega_flg & BIGNUM_POSITIVE_P(z)) {
+    if (nega_flg && BIGNUM_POSITIVE_P(z) && !BIGZEROP(z)) {
         z = rb_big_minus(z, m);
     }
     RB_GC_GUARD(x);
@@ -7009,7 +7157,7 @@ int_pow_tmp3(VALUE x, VALUE y, VALUE m, int nega_flg)
         x = rb_int_modulo(x, m);
     }
 
-    if (nega_flg && rb_int_positive_p(tmp)) {
+    if (nega_flg && rb_int_positive_p(tmp) && !rb_int_zero_p(tmp)) {
         tmp = rb_int_minus(tmp, m);
     }
     return tmp;
@@ -7121,6 +7269,11 @@ rb_int_powm(int const argc, VALUE * const argv, VALUE const num)
             rb_raise(rb_eTypeError, "Integer#pow() 2nd argument not allowed unless all arguments are integers");
         }
 
+        if (rb_int_zero_p(a) && !rb_int_zero_p(b)) {
+            /* shortcut; 0**x => 0 except for x == 0 */
+            return INT2FIX(0);
+        }
+
         if (rb_int_negative_p(m)) {
             m = rb_int_uminus(m);
             nega_flg = 1;
@@ -7130,6 +7283,7 @@ rb_int_powm(int const argc, VALUE * const argv, VALUE const num)
             long const half_val = (long)HALF_LONG_MSB;
             long const mm = FIX2LONG(m);
             if (!mm) rb_num_zerodiv();
+            if (mm == 1) return INT2FIX(0);
             if (mm <= half_val) {
                 return int_pow_tmp1(rb_int_modulo(a, m), b, mm, nega_flg);
             }
@@ -7139,6 +7293,7 @@ rb_int_powm(int const argc, VALUE * const argv, VALUE const num)
         }
         else {
             if (rb_bigzero_p(m)) rb_num_zerodiv();
+            if (bignorm(m) == INT2FIX(1)) return INT2FIX(0);
             return int_pow_tmp3(rb_int_modulo(a, m), b, m, nega_flg);
         }
     }
@@ -7166,16 +7321,9 @@ rb_int_powm(int const argc, VALUE * const argv, VALUE const num)
 void
 Init_Bignum(void)
 {
-#ifndef RUBY_INTEGER_UNIFICATION
-    rb_cBignum = rb_cInteger;
-#endif
-    /* An obsolete class, use Integer */
-    rb_define_const(rb_cObject, "Bignum", rb_cInteger);
-    rb_deprecate_constant(rb_cObject, "Bignum");
-
     rb_define_method(rb_cInteger, "coerce", rb_int_coerce, 1);
 
-#ifdef USE_GMP
+#if USE_GMP
     /* The version of loaded GMP. */
     rb_define_const(rb_cInteger, "GMP_VERSION", rb_sprintf("GMP %s", gmp_version));
 #endif
diff --git a/bin/bundle b/bin/bundle
deleted file mode 100755
index 1a0b06b005..0000000000
--- a/bin/bundle
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'bundler' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-str = ARGV.first
-if str
-  str = str.b[/\A_(.*)_\z/, 1]
-  if str and Gem::Version.correct?(str)
-    version = str
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('bundler', 'bundle', version)
-else
-gem "bundler", version
-load Gem.bin_path("bundler", "bundle", version)
-end
diff --git a/bin/bundler b/bin/bundler
deleted file mode 100755
index e15eb39ed7..0000000000
--- a/bin/bundler
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'bundler' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-str = ARGV.first
-if str
-  str = str.b[/\A_(.*)_\z/, 1]
-  if str and Gem::Version.correct?(str)
-    version = str
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('bundler', 'bundler', version)
-else
-gem "bundler", version
-load Gem.bin_path("bundler", "bundler", version)
-end
diff --git a/bin/erb b/bin/erb
deleted file mode 100755
index d5e51ee969..0000000000
--- a/bin/erb
+++ /dev/null
@@ -1,176 +0,0 @@
-#!/usr/bin/env ruby
-# Tiny eRuby --- ERB2
-# Copyright (c) 1999-2000,2002 Masatoshi SEKI
-# You can redistribute it and/or modify it under the same terms as Ruby.
-
-require 'erb'
-
-class ERB
-  module Main
-    def ARGV.switch
-      return nil if self.empty?
-      arg = self.shift
-      return nil if arg == '--'
-      case arg
-      when /\A-(.)(.*)/
-        if $1 == '-'
-          arg, @maybe_arg = arg.split(/=/, 2)
-          return arg
-        end
-        raise 'unknown switch "-"' if $2[0] == ?- and $1 != 'T'
-        if $2.size > 0
-          self.unshift "-#{$2}"
-          @maybe_arg = $2
-        else
-          @maybe_arg = nil
-        end
-        "-#{$1}"
-      when /\A(\w+)=/
-        arg
-      else
-        self.unshift arg
-        nil
-      end
-    end
-
-    def ARGV.req_arg
-      (@maybe_arg || self.shift || raise('missing argument')).tap {
-        @maybe_arg = nil
-      }
-    end
-
-    def trim_mode_opt(trim_mode, disable_percent)
-      return trim_mode if disable_percent
-      case trim_mode
-      when 0
-        return '%'
-      when 1
-        return '%>'
-      when 2
-        return '%<>'
-      when '-'
-        return '%-'
-      end
-    end
-    module_function :trim_mode_opt
-
-    def run(factory=ERB)
-      trim_mode = 0
-      disable_percent = false
-      variables = {}
-      begin
-        while switch = ARGV.switch
-          case switch
-          when '-x'                        # ruby source
-            output = true
-          when '-n'                        # line number
-            number = true
-          when '-v'                        # verbose
-            $VERBOSE = true
-          when '--version'                 # version
-            STDERR.puts factory.version
-            exit
-          when '-d', '--debug'             # debug
-            $DEBUG = true
-          when '-r'                        # require
-            require ARGV.req_arg
-          when '-S'                        # security level
-            warn 'warning: -S option of erb command is deprecated. Please do not use this.'
-            arg = ARGV.req_arg
-            raise "invalid safe_level #{arg.dump}" unless arg =~ /\A[0-1]\z/
-            safe_level = arg.to_i
-          when '-T'                        # trim mode
-            arg = ARGV.req_arg
-            if arg == '-'
-              trim_mode = arg
-              next
-            end
-            raise "invalid trim mode #{arg.dump}" unless arg =~ /\A[0-2]\z/
-            trim_mode = arg.to_i
-          when '-E', '--encoding'
-            arg = ARGV.req_arg
-            set_encoding(*arg.split(/:/, 2))
-          when '-U'
-            set_encoding(Encoding::UTF_8, Encoding::UTF_8)
-          when '-P'
-            disable_percent = true
-          when '--help'
-            raise "print this help"
-          when /\A-/
-            raise "unknown switch #{switch.dump}"
-          else
-            var, val = *switch.split('=', 2)
-            (variables ||= {})[var] = val
-          end
-        end
-      rescue                               # usage
-        STDERR.puts $!.to_s
-        STDERR.puts File.basename($0) +
-          " [switches] [var=value...] [inputfile]"
-        STDERR.puts <<EOU
-  -x               print ruby script
-  -n               print ruby script with line number
-  -v               enable verbose mode
-  -d               set $DEBUG to true
-  -r library       load a library
-  -E ex[:in]       set default external/internal encodings
-  -U               set default encoding to UTF-8
-  -T trim_mode     specify trim_mode (0..2, -)
-  -P               disable ruby code evaluation for lines beginning with %
-  var=value        set variable
-EOU
-        exit 1
-      end
-
-      $<.set_encoding(Encoding::UTF_8, nil)
-      src = $<.read
-      filename = $FILENAME
-      exit 2 unless src
-      trim = trim_mode_opt(trim_mode, disable_percent)
-      if safe_level.nil?
-        erb = factory.new(src.untaint, trim_mode: trim)
-      else
-        # [deprecated] This will be removed at Ruby 2.7.
-        erb = factory.new(src.untaint, safe_level, trim_mode: trim)
-      end
-      erb.filename = filename
-      if output
-        if number
-          erb.src.each_line.with_index do |line, l|
-            puts "%3d %s"%[l+1, line]
-          end
-        else
-          puts erb.src
-        end
-      else
-        bind = TOPLEVEL_BINDING.taint
-        if variables
-          enc = erb.encoding
-          for var, val in variables do
-            val = val.encode(enc) if val
-            bind.local_variable_set(var, val)
-          end
-        end
-        erb.run(bind)
-      end
-    end
-    module_function :run
-
-    def set_encoding(extern, intern = nil)
-      verbose, $VERBOSE = $VERBOSE, nil
-      Encoding.default_external = extern unless extern.nil? || extern == ""
-      Encoding.default_internal = intern unless intern.nil? || intern == ""
-      [$stdin, $stdout, $stderr].each do |io|
-        io.set_encoding(extern, intern)
-      end
-    ensure
-      $VERBOSE = verbose
-    end
-    module_function :set_encoding
-    class << self; private :set_encoding; end
-  end
-end
-
-if __FILE__ == $0
-  ERB::Main.run
-end
diff --git a/bin/gem b/bin/gem
index a4ec754abb..3ac1d9e623 100755
--- a/bin/gem
+++ b/bin/gem
@@ -1,25 +1,12 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
 # See LICENSE.txt for permissions.
 #++
 
-require 'rubygems'
-require 'rubygems/gem_runner'
-require 'rubygems/exceptions'
-
-required_version = Gem::Requirement.new ">= 1.8.7"
-
-unless required_version.satisfied_by? Gem.ruby_version then
-  abort "Expected Ruby Version #{required_version}, is #{Gem.ruby_version}"
-end
-
-args = ARGV.clone
-
-begin
-  Gem::GemRunner.new.run args
-rescue Gem::SystemExitException => e
-  exit e.exit_code
-end
+require "rubygems/gem_runner"
 
+Gem::GemRunner.new.run ARGV.clone
diff --git a/bin/irb b/bin/irb
deleted file mode 100755
index ae6d358c9d..0000000000
--- a/bin/irb
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'irb' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-str = ARGV.first
-if str
-  str = str.b[/\A_(.*)_\z/, 1]
-  if str and Gem::Version.correct?(str)
-    version = str
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('irb', 'irb', version)
-else
-gem "irb", version
-load Gem.bin_path("irb", "irb", version)
-end
diff --git a/bin/racc b/bin/racc
deleted file mode 100755
index 3ddac532b4..0000000000
--- a/bin/racc
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'racc' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-if ARGV.first
-  str = ARGV.first
-  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
-  if str =~ /\A_(.*)_\z/ and Gem::Version.correct?($1) then
-    version = $1
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('racc', 'racc', version)
-else
-gem "racc", version
-load Gem.bin_path("racc", "racc", version)
-end
diff --git a/bin/racc2y b/bin/racc2y
deleted file mode 100755
index a1e4352632..0000000000
--- a/bin/racc2y
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'racc' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-if ARGV.first
-  str = ARGV.first
-  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
-  if str =~ /\A_(.*)_\z/ and Gem::Version.correct?($1) then
-    version = $1
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('racc', 'racc2y', version)
-else
-gem "racc", version
-load Gem.bin_path("racc", "racc2y", version)
-end
diff --git a/bin/rdoc b/bin/rdoc
deleted file mode 100755
index 8fa948cddb..0000000000
--- a/bin/rdoc
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'rdoc' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-str = ARGV.first
-if str
-  str = str.b[/\A_(.*)_\z/, 1]
-  if str and Gem::Version.correct?(str)
-    version = str
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('rdoc', 'rdoc', version)
-else
-gem "rdoc", version
-load Gem.bin_path("rdoc", "rdoc", version)
-end
diff --git a/bin/ri b/bin/ri
deleted file mode 100755
index 0cc2f73bb6..0000000000
--- a/bin/ri
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'rdoc' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-str = ARGV.first
-if str
-  str = str.b[/\A_(.*)_\z/, 1]
-  if str and Gem::Version.correct?(str)
-    version = str
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('rdoc', 'ri', version)
-else
-gem "rdoc", version
-load Gem.bin_path("rdoc", "ri", version)
-end
diff --git a/bin/y2racc b/bin/y2racc
deleted file mode 100755
index 023615f369..0000000000
--- a/bin/y2racc
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/usr/bin/env ruby
-#
-# This file was generated by RubyGems.
-#
-# The application 'racc' is installed as part of a gem, and
-# this file is here to facilitate running it.
-#
-
-require 'rubygems'
-
-version = ">= 0.a"
-
-if ARGV.first
-  str = ARGV.first
-  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
-  if str =~ /\A_(.*)_\z/ and Gem::Version.correct?($1) then
-    version = $1
-    ARGV.shift
-  end
-end
-
-if Gem.respond_to?(:activate_bin_path)
-load Gem.activate_bin_path('racc', 'y2racc', version)
-else
-gem "racc", version
-load Gem.bin_path("racc", "y2racc", version)
-end
diff --git a/bootstraptest/pending.rb b/bootstraptest/pending.rb
index 0959bfa2b0..2c4b85a419 100644
--- a/bootstraptest/pending.rb
+++ b/bootstraptest/pending.rb
@@ -1,19 +1,3 @@
-assert_equal 'A', %q{
-  class A
-    @@a = 'A'
-    def a=(x)
-      @@a = x
-    end
-    def a
-      @@a
-    end
-  end
-
-  B = A.dup
-  B.new.a = 'B'
-  A.new.a
-}, '[ruby-core:17019]'
-
 assert_equal 'ok', %q{
   def m
     lambda{
@@ -31,13 +15,6 @@ assert_equal 'ok', %q{
   end
 }
 
-assert_normal_exit %q{
-  r = Range.allocate
-  def r.<=>(o) true end
-  r.instance_eval { initialize r, r }
-  r.inspect
-}
-
 # This randomly fails on mswin.
 assert_equal %q{[]}, %q{
   Thread.new{sleep}.backtrace
diff --git a/bootstraptest/runner.rb b/bootstraptest/runner.rb
index 56b4b12230..04de0c93b9 100755
--- a/bootstraptest/runner.rb
+++ b/bootstraptest/runner.rb
@@ -6,7 +6,8 @@
 # Never use optparse in this file.
 # Never use test/unit in this file.
 # Never use Ruby extensions in this file.
-# Maintain Ruby 1.8 compatibility for now
+
+$start_time = Time.now
 
 begin
   require 'fileutils'
@@ -15,6 +16,7 @@ rescue LoadError
   $:.unshift File.join(File.dirname(__FILE__), '../lib')
   retry
 end
+require_relative '../tool/lib/test/jobserver'
 
 if !Dir.respond_to?(:mktmpdir)
   # copied from lib/tmpdir.rb
@@ -58,24 +60,99 @@ if !Dir.respond_to?(:mktmpdir)
   end
 end
 
+# Configuration
+bt = Struct.new(:ruby,
+                :verbose,
+                :color,
+                :tty,
+                :quiet,
+                :wn,
+                :progress,
+                :progress_bs,
+                :passed,
+                :failed,
+                :reset,
+                :columns,
+                :window_width,
+                :width,
+                :indent,
+                :platform,
+                :timeout,
+                :timeout_scale,
+                :launchable_test_reports
+                )
+BT = Class.new(bt) do
+  def indent=(n)
+    super
+    if (self.columns ||= 0) < n
+      $stderr.print(' ' * (n - self.columns))
+    end
+    self.columns = indent
+  end
+
+  def putc(c)
+    unless self.quiet
+      if self.window_width == nil
+        unless w = ENV["COLUMNS"] and (w = w.to_i) > 0
+          w = 80
+        end
+        w -= 1
+        self.window_width = w
+      end
+      if self.window_width and self.columns >= self.window_width
+        $stderr.print "\n", " " * (self.indent ||= 0)
+        self.columns = indent
+      end
+      $stderr.print c
+      $stderr.flush
+      self.columns += 1
+    end
+  end
+
+  def wn=(wn)
+    unless wn == 1
+      wn = Test::JobServer.max_jobs(wn > 0 ? wn : 1024, ENV.delete("MAKEFLAGS")) || wn
+      if wn <= 0
+        require 'etc'
+        wn = [Etc.nprocessors / 2, 1].max
+      end
+    end
+    super wn
+  end
+
+  def apply_timeout_scale(timeout)
+    timeout&.*(timeout_scale)
+  end
+end.new
+
+BT_STATE = Struct.new(:count, :error).new
+
 def main
-  @ruby = File.expand_path('miniruby')
-  @verbose = false
+  BT.ruby = File.expand_path('miniruby')
+  BT.verbose = false
   $VERBOSE = false
   $stress = false
-  @color = nil
-  @tty = nil
-  @quiet = false
+  BT.color = nil
+  BT.tty = nil
+  BT.quiet = false
+  BT.timeout = 180
+  BT.timeout_scale = 1
+  if (ts = (ENV["RUBY_TEST_TIMEOUT_SCALE"] || ENV["RUBY_TEST_SUBPROCESS_TIMEOUT_SCALE"]).to_i) > 1
+    BT.timeout_scale *= ts
+  end
+
+  # BT.wn = 1
   dir = nil
   quiet = false
   tests = nil
   ARGV.delete_if {|arg|
     case arg
     when /\A--ruby=(.*)/
-      @ruby = $1
-      @ruby.gsub!(/^([^ ]*)/){File.expand_path($1)}
-      @ruby.gsub!(/(\s+-I\s*)((?!(?:\.\/)*-(?:\s|\z))\S+)/){$1+File.expand_path($2)}
-      @ruby.gsub!(/(\s+-r\s*)(\.\.?\/\S+)/){$1+File.expand_path($2)}
+      ruby = $1
+      ruby.gsub!(/^([^ ]*)/){File.expand_path($1)}
+      ruby.gsub!(/(\s+-I\s*)((?!(?:\.\/)*-(?:\s|\z))\S+)/){$1+File.expand_path($2)}
+      ruby.gsub!(/(\s+-r\s*)(\.\.?\/\S+)/){$1+File.expand_path($2)}
+      BT.ruby = ruby
       true
     when /\A--sets=(.*)/
       tests = Dir.glob("#{File.dirname($0)}/test_{#{$1}}*.rb").sort
@@ -88,18 +165,27 @@ def main
       $stress = true
     when /\A--color(?:=(?:always|(auto)|(never)|(.*)))?\z/
       warn "unknown --color argument: #$3" if $3
-      @color = $1 ? nil : !$2
+      BT.color = color = $1 ? nil : !$2
       true
     when /\A--tty(=(?:yes|(no)|(.*)))?\z/
       warn "unknown --tty argument: #$3" if $3
-      @tty = !$1 || !$2
+      BT.tty = !$1 || !$2
       true
-    when /\A(-q|--q(uiet))\z/
+    when /\A(-q|--q(uiet)?)\z/
       quiet = true
-      @quiet = true
+      BT.quiet = true
+      true
+    when /\A-j(\d+)?/
+      BT.wn = $1.to_i
+      true
+    when /\A--timeout=(\d+(?:_\d+)*(?:\.\d+(?:_\d+)*)?)(?::(\d+(?:_\d+)*(?:\.\d+(?:_\d+)*)?))?/
+      BT.timeout = $1.to_f
+      BT.timeout_scale = $2.to_f if defined?($2)
+      true
+    when /\A(-v|--v(erbose)?)\z/
+      BT.verbose = true
+      BT.quiet = false
       true
-    when /\A(-v|--v(erbose))\z/
-      @verbose = true
     when /\A(-h|--h(elp)?)\z/
       puts(<<-End)
 Usage: #{File.basename($0, '.*')} --ruby=PATH [--sets=NAME,NAME,...]
@@ -108,6 +194,7 @@ Usage: #{File.basename($0, '.*')} --ruby=PATH [--sets=NAME,NAME,...]
                                     default: /tmp/bootstraptestXXXXX.tmpwd
         --color[=WHEN]              Colorize the output.  WHEN defaults to 'always'
                                     or can be 'never' or 'auto'.
+        --timeout=TIMEOUT           Default timeout in seconds.
     -s, --stress                    stress test.
     -v, --verbose                   Output test name before exec.
     -q, --quiet                     Don\'t print header message.
@@ -116,27 +203,53 @@ End
       exit true
     when /\A-j/
       true
+    when /--launchable-test-reports=(.*)/
+      if File.exist?($1)
+        # To protect files from overwritten, do nothing when the file exists.
+        return true
+      end
+
+      begin
+        require_relative '../tool/lib/launchable'
+      rescue LoadError
+        # The following error sometimes happens, so we're going to skip writing Launchable report files in this case.
+        #
+        # ```
+        # /tmp/tmp.bISss9CtXZ/.ext/common/json/ext.rb:15:in 'Kernel#require':
+        #   /tmp/tmp.bISss9CtXZ/.ext/x86_64-linux/json/ext/parser.so:
+        #     undefined symbol: ruby_abi_version - ruby_abi_version (LoadError)
+        # ```
+        #
+        return true
+      end
+      BT.launchable_test_reports = writer = Launchable::JsonStreamWriter.new($1)
+      writer.write_array('testCases')
+      at_exit {
+        writer.close
+      }
+      true
     else
       false
     end
   }
   if tests and not ARGV.empty?
-    $stderr.puts "--tests and arguments are exclusive"
-    exit false
+    abort "--sets and arguments are exclusive"
   end
   tests ||= ARGV
   tests = Dir.glob("#{File.dirname($0)}/test_*.rb").sort if tests.empty?
-  pathes = tests.map {|path| File.expand_path(path) }
+  paths = tests.map {|path| File.expand_path(path) }
 
-  @progress = %w[- \\ | /]
-  @progress_bs = "\b" * @progress[0].size
-  @tty = $stderr.tty? if @tty.nil?
-  case @color
+  BT.progress = %w[- \\ | /]
+  BT.progress_bs = "\b" * BT.progress[0].size
+  BT.tty = $stderr.tty? if BT.tty.nil?
+  BT.wn ||= /-j(\d+)?/ =~ (ENV["MAKEFLAGS"] || ENV["MFLAGS"]) ? $1.to_i : 1
+
+  case BT.color
   when nil
-    @color = @tty && /dumb/ !~ ENV["TERM"]
+    BT.color = BT.tty && /dumb/ !~ ENV["TERM"]
   end
-  @tty &&= !@verbose
-  if @color
+  BT.tty &&= !BT.verbose
+  if BT.color
     # dircolors-like style
     colors = (colors = ENV['TEST_COLORS']) ? Hash[colors.scan(/(\w+)=([^:\n]*)/)] : {}
     begin
@@ -145,196 +258,459 @@ End
       end
     rescue
     end
-    @passed = "\e[;#{colors["pass"] || "32"}m"
-    @failed = "\e[;#{colors["fail"] || "31"}m"
-    @reset = "\e[m"
+    BT.passed = "\e[;#{colors["pass"] || "32"}m"
+    BT.failed = "\e[;#{colors["fail"] || "31"}m"
+    BT.reset = "\e[m"
   else
-    @passed = @failed = @reset = ""
+    BT.passed = BT.failed = BT.reset = ""
   end
+  target_version = `#{BT.ruby} -v`.chomp
+  BT.platform = target_version[/\[(.*)\]\z/, 1]
   unless quiet
-    puts Time.now
+    puts $start_time
     if defined?(RUBY_DESCRIPTION)
       puts "Driver is #{RUBY_DESCRIPTION}"
     elsif defined?(RUBY_PATCHLEVEL)
-      puts "Driver is ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}#{RUBY_PLATFORM}) [#{RUBY_PLATFORM}]"
+      puts "Driver is ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}#{RUBY_PATCHLEVEL}) [#{RUBY_PLATFORM}]"
     else
       puts "Driver is ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}) [#{RUBY_PLATFORM}]"
     end
-    puts "Target is #{`#{@ruby} -v`.chomp}"
+    puts "Target is #{target_version}"
     puts
     $stdout.flush
   end
 
-  in_temporary_working_directory(dir) {
-    exec_test pathes
-  }
+  in_temporary_working_directory(dir) do
+    exec_test paths
+  end
 end
 
 def erase(e = true)
-  if e and @columns > 0 and @tty and !@verbose
+  if e and BT.columns > 0 and BT.tty and !BT.verbose
     "\e[1K\r"
   else
     ""
   end
 end
 
-def exec_test(pathes)
-  @count = 0
-  @error = 0
-  @errbuf = []
-  @location = nil
-  @columns = 0
-  @width = pathes.map {|path| File.basename(path).size}.max + 2
-  pathes.each do |path|
-    @basename = File.basename(path)
-    $stderr.printf("%s%-*s ", erase(@quiet), @width, @basename)
-    $stderr.flush
-    @columns = @width + 1
-    $stderr.puts if @verbose
-    count = @count
-    error = @error
+def load_test paths
+  paths.each do |path|
     load File.expand_path(path)
-    if @tty
-      if @error == error
-        msg = "PASS #{@count-count}"
-        @columns += msg.size - 1
-        $stderr.print "#{@progress_bs}#{@passed}#{msg}#{@reset}"
+  end
+end
+
+def concurrent_exec_test
+  aq = Queue.new
+  rq = Queue.new
+
+  ts = BT.wn.times.map do
+    Thread.new do
+      while as = aq.pop
+        as.call
+        rq << as
+      end
+    ensure
+      rq << nil
+    end
+  end
+
+  Assertion.all.to_a.shuffle.each do |path, assertions|
+    assertions.each do |as|
+      aq << as
+    end
+  end
+
+  BT.indent = 1
+  aq.close
+  i = 1
+  term_wn = 0
+  begin
+    while BT.wn != term_wn
+      if r = rq.pop
+        BT_STATE.count += 1
+        case
+        when BT.quiet
+        when BT.tty
+          $stderr.print "#{BT.progress_bs}#{BT.progress[(i+=1) % BT.progress.size]}"
+        else
+          BT.putc '.'
+        end
       else
-        msg = "FAIL #{@error-error}/#{@count-count}"
-        $stderr.print "#{@progress_bs}#{@failed}#{msg}#{@reset}"
-        @columns = 0
+        term_wn += 1
       end
     end
-    $stderr.puts unless @quiet and @tty and @error == error
+  ensure
+    ts.each(&:kill)
+    ts.each(&:join)
   end
-  $stderr.print(erase) if @quiet
-  @errbuf.each do |msg|
+end
+
+##
+# Module for writing a test file for uploading test results into Launchable.
+# In bootstraptest, we aggregate the test results based on file level.
+module Launchable
+  @@last_test_name = nil
+  @@failure_log = ''
+  @@duration = 0
+
+  def show_progress(message = '')
+    faildesc, t = super
+
+    if writer = BT.launchable_test_reports
+      if faildesc
+        @@failure_log += faildesc
+      end
+      repo_path = File.expand_path("#{__dir__}/../")
+      relative_path = File.join(__dir__, self.path).delete_prefix("#{repo_path}/")
+      if @@last_test_name != nil && @@last_test_name != relative_path
+        # The test path is a URL-encoded representation.
+        # https://github.com/launchableinc/cli/blob/v1.81.0/launchable/testpath.py#L18
+        test_path = "#{encode_test_path_component("file")}=#{encode_test_path_component(@@last_test_name)}"
+        if @@failure_log.size > 0
+          status = 'TEST_FAILED'
+        else
+          status = 'TEST_PASSED'
+        end
+        writer.write_object(
+          {
+            testPath: test_path,
+            status: status,
+            duration: t,
+            createdAt: Time.now.to_s,
+            stderr: @@failure_log,
+            stdout: nil,
+            data: {
+              lineNumber: self.lineno
+            }
+          }
+        )
+        @@duration = 0
+        @@failure_log = ''
+      end
+      @@last_test_name = relative_path
+      @@duration += t
+    end
+  end
+
+  private
+  def encode_test_path_component component
+    component.to_s.gsub('%', '%25').gsub('=', '%3D').gsub('#', '%23').gsub('&', '%26')
+  end
+end
+
+def exec_test(paths)
+  # setup
+  load_test paths
+  BT_STATE.count = 0
+  BT_STATE.error = 0
+  BT.columns = 0
+  BT.width = paths.map {|path| File.basename(path).size}.max + 2
+
+  # execute tests
+  if BT.wn > 1
+    concurrent_exec_test
+  else
+    prev_basename = nil
+    Assertion.all.each do |basename, assertions|
+      if !BT.quiet && basename != prev_basename
+        prev_basename = basename
+        $stderr.printf("%s%-*s ", erase(BT.quiet), BT.width, basename)
+        $stderr.flush
+      end
+      BT.columns = BT.width + 1
+      $stderr.puts if BT.verbose
+      count = BT_STATE.count
+      error = BT_STATE.error
+
+      assertions.each do |assertion|
+        BT_STATE.count += 1
+        assertion.call
+      end
+
+      if BT.tty
+        if BT_STATE.error == error
+          msg = "PASS #{BT_STATE.count-count}"
+          BT.columns += msg.size - 1
+          $stderr.print "#{BT.progress_bs}#{BT.passed}#{msg}#{BT.reset}" unless BT.quiet
+        else
+          msg = "FAIL #{BT_STATE.error-error}/#{BT_STATE.count-count}"
+          $stderr.print "#{BT.progress_bs}#{BT.failed}#{msg}#{BT.reset}"
+          BT.columns = 0
+        end
+      end
+      $stderr.puts if !BT.quiet and (BT.tty or BT_STATE.error == error)
+    end
+  end
+
+  # show results
+  unless BT.quiet
+    $stderr.puts(erase)
+
+    sec = Time.now - $start_time
+    $stderr.puts "Finished in #{'%.2f' % sec} sec\n\n" if Assertion.count > 0
+  end
+
+  Assertion.errbuf.each do |msg|
     $stderr.puts msg
   end
-  if @error == 0
-    if @count == 0
-      $stderr.puts "No tests, no problem"
+
+  out = BT.quiet ? $stdout : $stderr
+
+  if BT_STATE.error == 0
+    if Assertion.count == 0
+      out.puts "No tests, no problem" unless BT.quiet
     else
-      $stderr.puts "#{@passed}PASS#{@reset} all #{@count} tests"
+      out.puts "#{BT.passed}PASS#{BT.reset} all #{Assertion.count} tests"
     end
-    exit true
+    true
   else
-    $stderr.puts "#{@failed}FAIL#{@reset} #{@error}/#{@count} tests failed"
-    exit false
+    $stderr.puts "#{BT.failed}FAIL#{BT.reset} #{BT_STATE.error}/#{BT_STATE.count} tests failed"
+    false
   end
 end
 
-def show_progress(message = '')
-  if @verbose
-    $stderr.print "\##{@count} #{@location} "
-  elsif @tty
-    $stderr.print "#{@progress_bs}#{@progress[@count % @progress.size]}"
-  end
-  t = Time.now if @verbose
-  faildesc, errout = with_stderr {yield}
-  t = Time.now - t if @verbose
-  if !faildesc
-    if @tty
-      $stderr.print "#{@progress_bs}#{@progress[@count % @progress.size]}"
-    elsif @verbose
-      $stderr.printf(". %.3f\n", t)
-    else
-      $stderr.print '.'
+def target_platform
+  BT.platform or RUBY_PLATFORM
+end
+
+class Assertion < Struct.new(:src, :path, :lineno, :proc)
+  prepend Launchable
+  @count = 0
+  @all = Hash.new{|h, k| h[k] = []}
+  @errbuf = []
+
+  class << self
+    attr_reader :count, :errbuf
+
+    def all
+      @all
     end
-  else
-    $stderr.print "#{@failed}F"
-    $stderr.printf(" %.3f", t) if @verbose
-    $stderr.print @reset
-    $stderr.puts if @verbose
-    error faildesc, message
-    unless errout.empty?
-      $stderr.print "#{@failed}stderr output is not empty#{@reset}\n", adjust_indent(errout)
+
+    def add as
+      @all[as.path] << as
+      as.id = (@count += 1)
     end
-    if @tty and !@verbose
-      $stderr.printf("%-*s%s", @width, @basename, @progress[@count % @progress.size])
+  end
+
+  attr_accessor :id
+  attr_reader :err, :category
+
+  def initialize(*args)
+    super
+    self.class.add self
+    @category = self.path[/\Atest_(.+)\.rb\z/, 1]
+  end
+
+  def call
+    self.proc.call self
+  end
+
+  def assert_check(message = '', opt = '', **argh)
+    show_progress(message) {
+      result = get_result_string(opt, **argh)
+      yield(result)
+    }
+  end
+
+  def with_stderr
+    out = err = nil
+    r, w = IO.pipe
+    @err = w
+    err_reader = Thread.new{ r.read }
+
+    begin
+      out = yield
+    ensure
+      w.close
+      err = err_reader.value
+      r.close rescue nil
     end
+
+    return out, err
   end
-rescue Interrupt
-  $stderr.puts "\##{@count} #{@location}"
-  raise
-rescue Exception => err
-  $stderr.print 'E'
-  $stderr.puts if @verbose
-  error err.message, message
-end
 
-def show_limit(testsrc, opt = '', **argh)
-  result = get_result_string(testsrc, opt, **argh)
-  if @tty and @verbose
-    $stderr.puts ".{#@reset}\n#{erase}#{result}"
-  else
-    @errbuf.push result
+  def show_error(msg, additional_message)
+    msg = "#{BT.failed}\##{self.id} #{self.path}:#{self.lineno}#{BT.reset}: #{msg}  #{additional_message}"
+    if BT.tty
+      $stderr.puts "#{erase}#{msg}"
+    else
+      Assertion.errbuf << msg
+    end
+    BT_STATE.error += 1
   end
-end
 
-def assert_check(testsrc, message = '', opt = '', **argh)
-  show_progress(message) {
-    result = get_result_string(testsrc, opt, **argh)
-    check_coredump
-    yield(result)
-  }
-end
 
-def assert_equal(expected, testsrc, message = '', opt = '', **argh)
-  newtest
-  assert_check(testsrc, message, opt, **argh) {|result|
-    if expected == result
-      nil
+  def show_progress(message = '')
+    if BT.quiet || BT.wn > 1
+      # do nothing
+    elsif BT.verbose
+      $stderr.print "\##{@id} #{self.path}:#{self.lineno} "
+    elsif BT.tty
+      $stderr.print "#{BT.progress_bs}#{BT.progress[BT_STATE.count % BT.progress.size]}"
+    end
+
+    t = Time.now if BT.verbose || BT.launchable_test_reports
+    faildesc, errout = with_stderr {yield}
+    t = Time.now - t if BT.verbose || BT.launchable_test_reports
+
+    if !faildesc
+      # success
+      if BT.quiet || BT.wn > 1
+        # do nothing
+      elsif BT.tty
+        $stderr.print "#{BT.progress_bs}#{BT.progress[BT_STATE.count % BT.progress.size]}"
+      elsif BT.verbose
+        $stderr.printf(". %.3f\n", t)
+      else
+        BT.putc '.'
+      end
     else
-      desc = "#{result.inspect} (expected #{expected.inspect})"
-      pretty(testsrc, desc, result)
+      $stderr.print "#{BT.failed}F"
+      $stderr.printf(" %.3f", t) if BT.verbose
+      $stderr.print BT.reset
+      $stderr.puts if BT.verbose
+      show_error faildesc, message
+      unless errout.empty?
+        $stderr.print "#{BT.failed}stderr output is not empty#{BT.reset}\n", adjust_indent(errout)
+      end
+
+      if BT.tty and !BT.verbose and BT.wn == 1
+        $stderr.printf("%-*s%s", BT.width, path, BT.progress[BT_STATE.count % BT.progress.size])
+      end
     end
-  }
-end
 
-def assert_match(expected_pattern, testsrc, message = '')
-  newtest
-  assert_check(testsrc, message) {|result|
-    if expected_pattern =~ result
-      nil
+    [faildesc, t]
+  rescue Interrupt
+    $stderr.puts "\##{@id} #{path}:#{lineno}"
+    raise
+  rescue Exception => err
+    $stderr.print 'E'
+    $stderr.puts if BT.verbose
+    show_error err.message, message
+  ensure
+    begin
+      check_coredump
+    rescue CoreDumpError => err
+      $stderr.print 'E'
+      $stderr.puts if BT.verbose
+      show_error err.message, message
+      cleanup_coredump
+    end
+  end
+
+  class Timeout < StandardError; end
+
+  def get_result_string(opt = '', timeout: BT.timeout, **argh)
+    if BT.ruby
+      timeout = BT.apply_timeout_scale(timeout)
+      filename = make_srcfile(**argh)
+      begin
+        kw = self.err ? {err: self.err} : {}
+        out = IO.popen("#{BT.ruby} -W0 #{opt} #{filename}", **kw)
+        pid = out.pid
+        th = Thread.new {out.read.tap {Process.waitpid(pid); out.close}}
+        if th.join(timeout)
+          th.value
+        else
+          Timeout.new("timed out after #{timeout} seconds")
+        end
+      ensure
+        raise Interrupt if $? and $?.signaled? && $?.termsig == Signal.list["INT"]
+
+        begin
+          Process.kill :KILL, pid
+        rescue Errno::ESRCH
+          # OK
+        end
+      end
     else
-      desc = "#{expected_pattern.inspect} expected to be =~\n#{result.inspect}"
-      pretty(testsrc, desc, result)
+      eval(src).to_s
     end
-  }
+  end
+
+  def make_srcfile(frozen_string_literal: nil)
+    filename = "bootstraptest.#{self.path}_#{self.lineno}_#{self.id}.rb"
+    File.open(filename, 'w') {|f|
+      f.puts "#frozen_string_literal:#{frozen_string_literal}" unless frozen_string_literal.nil?
+      if $stress
+        f.puts "GC.stress = true" if $stress
+      else
+        f.puts ""
+      end
+      f.puts "class BT_Skip < Exception; end; def skip(msg) = raise(BT_Skip, msg.to_s)"
+      f.puts "print(begin; #{self.src}; rescue BT_Skip; $!.message; end)"
+    }
+    filename
+  end
+end
+
+def add_assertion src, pr
+  loc = caller_locations(2, 1).first
+  lineno = loc.lineno
+  path = File.basename(loc.path)
+
+  Assertion.new(src, path, lineno, pr)
+end
+
+def assert_equal(expected, testsrc, message = '', opt = '', **kwargs)
+  add_assertion testsrc, -> as do
+    as.assert_check(message, opt, **kwargs) {|result|
+      if expected == result
+        nil
+      else
+        desc = "#{result.inspect} (expected #{expected.inspect})"
+        pretty(testsrc, desc, result)
+      end
+    }
+  end
+end
+
+def assert_match(expected_pattern, testsrc, message = '', **argh)
+  add_assertion testsrc, -> as do
+    as.assert_check(message, **argh) {|result|
+      if expected_pattern =~ result
+        nil
+      else
+        desc = "#{expected_pattern.inspect} expected to be =~\n#{result.inspect}"
+        pretty(testsrc, desc, result)
+      end
+    }
+  end
 end
 
 def assert_not_match(unexpected_pattern, testsrc, message = '')
-  newtest
-  assert_check(testsrc, message) {|result|
-    if unexpected_pattern !~ result
-      nil
-    else
-      desc = "#{unexpected_pattern.inspect} expected to be !~\n#{result.inspect}"
-      pretty(testsrc, desc, result)
-    end
-  }
+  add_assertion testsrc, -> as do
+    as.assert_check(message) {|result|
+      if unexpected_pattern !~ result
+        nil
+      else
+        desc = "#{unexpected_pattern.inspect} expected to be !~\n#{result.inspect}"
+        pretty(testsrc, desc, result)
+      end
+    }
+  end
 end
 
 def assert_valid_syntax(testsrc, message = '')
-  newtest
-  assert_check(testsrc, message, '-c') {|result|
-    result if /Syntax OK/ !~ result
-  }
+  add_assertion testsrc, -> as do
+    as.assert_check(message, '-c') {|result|
+      result if /Syntax OK/ !~ result
+    }
+  end
 end
 
-def assert_normal_exit(testsrc, *rest, timeout: nil, **opt)
-  newtest
-  message, ignore_signals = rest
-  message ||= ''
-  show_progress(message) {
-    faildesc = nil
-    filename = make_srcfile(testsrc)
-    old_stderr = $stderr.dup
-    timeout_signaled = false
-    begin
-      $stderr.reopen("assert_normal_exit.log", "w")
-      io = IO.popen("#{@ruby} -W0 #{filename}")
+def assert_normal_exit(testsrc, *rest, timeout: BT.timeout, **opt)
+  add_assertion testsrc, -> as do
+    timeout = BT.apply_timeout_scale(timeout)
+    message, ignore_signals = rest
+    message ||= ''
+    as.show_progress(message) {
+      faildesc = nil
+      filename = as.make_srcfile
+      timeout_signaled = false
+      logfile = "assert_normal_exit.#{as.path}.#{as.lineno}.log"
+
+      io = IO.popen("#{BT.ruby} -W0 #{filename}", err: logfile)
       pid = io.pid
       th = Thread.new {
         io.read
@@ -346,83 +722,93 @@ def assert_normal_exit(testsrc, *rest, timeout: nil, **opt)
         timeout_signaled = true
       end
       status = th.value
-    ensure
-      $stderr.reopen(old_stderr)
-      old_stderr.close
-    end
-    if status && status.signaled?
-      signo = status.termsig
-      signame = Signal.list.invert[signo]
-      unless ignore_signals and ignore_signals.include?(signame)
-        sigdesc = "signal #{signo}"
-        if signame
-          sigdesc = "SIG#{signame} (#{sigdesc})"
-        end
-        if timeout_signaled
-          sigdesc << " (timeout)"
-        end
-        faildesc = pretty(testsrc, "killed by #{sigdesc}", nil)
-        stderr_log = File.read("assert_normal_exit.log")
-        if !stderr_log.empty?
-          faildesc << "\n" if /\n\z/ !~ faildesc
-          stderr_log << "\n" if /\n\z/ !~ stderr_log
-          stderr_log.gsub!(/^.*\n/) { '| ' + $& }
-          faildesc << stderr_log
+
+      if status && status.signaled?
+        signo = status.termsig
+        signame = Signal.list.invert[signo]
+        unless ignore_signals and ignore_signals.include?(signame)
+          sigdesc = "signal #{signo}"
+          if signame
+            sigdesc = "SIG#{signame} (#{sigdesc})"
+          end
+          if timeout_signaled
+            sigdesc << " (timeout)"
+          end
+          faildesc = pretty(testsrc, "killed by #{sigdesc}", nil)
+          stderr_log = File.read(logfile)
+          if !stderr_log.empty?
+            faildesc << "\n" if /\n\z/ !~ faildesc
+            stderr_log << "\n" if /\n\z/ !~ stderr_log
+            stderr_log.gsub!(/^.*\n/) { '| ' + $& }
+            faildesc << stderr_log
+          end
         end
       end
-    end
-    faildesc
-  }
+      faildesc
+    }
+  end
 end
 
 def assert_finish(timeout_seconds, testsrc, message = '')
-  if RubyVM.const_defined? :MJIT
-    timeout_seconds *= 3 if RubyVM::MJIT.enabled? # for --jit-wait
-  end
-  newtest
-  show_progress(message) {
-    faildesc = nil
-    filename = make_srcfile(testsrc)
-    io = IO.popen("#{@ruby} -W0 #{filename}")
-    pid = io.pid
-    waited = false
-    tlimit = Time.now + timeout_seconds
-    diff = timeout_seconds
-    while diff > 0
-      if Process.waitpid pid, Process::WNOHANG
-        waited = true
-        break
-      end
-      if io.respond_to?(:read_nonblock)
-        if IO.select([io], nil, nil, diff)
-          begin
-            io.read_nonblock(1024)
-          rescue Errno::EAGAIN, IO::WaitReadable, EOFError
-            break
-          end while true
+  add_assertion testsrc, -> as do
+    timeout_seconds = BT.apply_timeout_scale(timeout_seconds)
+
+    as.show_progress(message) {
+      faildesc = nil
+      filename = as.make_srcfile
+      io = IO.popen("#{BT.ruby} -W0 #{filename}", err: as.err)
+      pid = io.pid
+      waited = false
+      tlimit = Time.now + timeout_seconds
+      diff = timeout_seconds
+      while diff > 0
+        if Process.waitpid pid, Process::WNOHANG
+          waited = true
+          break
         end
-      else
-        sleep 0.1
+        if io.respond_to?(:read_nonblock)
+          if IO.select([io], nil, nil, diff)
+            begin
+              io.read_nonblock(1024)
+            rescue Errno::EAGAIN, IO::WaitReadable, EOFError
+              break
+            end while true
+          end
+        else
+          sleep 0.1
+        end
+        diff = tlimit - Time.now
       end
-      diff = tlimit - Time.now
-    end
-    if !waited
-      Process.kill(:KILL, pid)
-      Process.waitpid pid
-      faildesc = pretty(testsrc, "not finished in #{timeout_seconds} seconds", nil)
-    end
-    io.close
-    faildesc
-  }
+      if !waited
+        Process.kill(:KILL, pid)
+        Process.waitpid pid
+        faildesc = pretty(testsrc, "not finished in #{timeout_seconds} seconds", nil)
+      end
+      io.close
+      faildesc
+    }
+  end
 end
 
 def flunk(message = '')
-  newtest
-  show_progress('') { message }
+  add_assertion '', -> as do
+    as.show_progress('') { message }
+  end
+end
+
+def show_limit(testsrc, opt = '', **argh)
+  return if BT.quiet
+
+  add_assertion testsrc, -> as do
+    result = as.get_result_string(opt, **argh)
+    Assertion.errbuf << result
+  end
 end
 
 def pretty(src, desc, result)
   src = src.sub(/\A\s*\n/, '')
+  lines = src.lines
+  src = lines[0..20].join + "(...snip)\n" if lines.size > 20
   (/\n/ =~ src ? "\n#{adjust_indent(src)}" : src) + "  #=> #{desc}"
 end
 
@@ -436,67 +822,6 @@ def untabify(str)
   str.gsub(/^\t+/) {' ' * (8 * $&.size) }
 end
 
-def make_srcfile(src, frozen_string_literal: nil)
-  filename = 'bootstraptest.tmp.rb'
-  File.open(filename, 'w') {|f|
-    f.puts "#frozen_string_literal:true" if frozen_string_literal
-    f.puts "GC.stress = true" if $stress
-    f.puts "print(begin; #{src}; end)"
-  }
-  filename
-end
-
-def get_result_string(src, opt = '', **argh)
-  if @ruby
-    filename = make_srcfile(src, **argh)
-    begin
-      `#{@ruby} -W0 #{opt} #{filename}`
-    ensure
-      raise Interrupt if $? and $?.signaled? && $?.termsig == Signal.list["INT"]
-      raise CoreDumpError, "core dumped" if $? and $?.coredump?
-    end
-  else
-    eval(src).to_s
-  end
-end
-
-def with_stderr
-  out = err = nil
-  begin
-    r, w = IO.pipe
-    stderr = $stderr.dup
-    $stderr.reopen(w)
-    w.close
-    reader = Thread.start {r.read}
-    begin
-      out = yield
-    ensure
-      $stderr.reopen(stderr)
-      err = reader.value
-    end
-  ensure
-    w.close rescue nil
-    r.close rescue nil
-  end
-  return out, err
-end
-
-def newtest
-  @location = File.basename(caller(2).first)
-  @count += 1
-  cleanup_coredump
-end
-
-def error(msg, additional_message)
-  msg = "#{@failed}\##{@count} #{@location}#{@reset}: #{msg}  #{additional_message}"
-  if @tty
-    $stderr.puts "#{erase}#{msg}"
-  else
-    @errbuf.push msg
-  end
-  @error += 1
-end
-
 def in_temporary_working_directory(dir)
   if dir
     Dir.mkdir dir
@@ -513,18 +838,40 @@ def in_temporary_working_directory(dir)
 end
 
 def cleanup_coredump
-  FileUtils.rm_f 'core'
+  if File.file?('core')
+    require 'time'
+    Dir.glob('/tmp/bootstraptest-core.*').each do |f|
+      if Time.now - File.mtime(f) > 7 * 24 * 60 * 60 # 7 days
+        warn "Deleting an old core file: #{f}"
+        FileUtils.rm(f)
+      end
+    end
+    core_path = "/tmp/bootstraptest-core.#{Time.now.utc.iso8601}"
+    warn "A core file is found. Saving it at: #{core_path.dump}"
+    FileUtils.mv('core', core_path)
+    cmd = ['gdb', BT.ruby, '-c', core_path, '-ex', 'bt', '-batch']
+    p cmd # debugging why it's not working
+    system(*cmd)
+  end
   FileUtils.rm_f Dir.glob('core.*')
-  FileUtils.rm_f @ruby+'.stackdump' if @ruby
+  FileUtils.rm_f BT.ruby+'.stackdump' if BT.ruby
 end
 
 class CoreDumpError < StandardError; end
 
 def check_coredump
   if File.file?('core') or not Dir.glob('core.*').empty? or
-      (@ruby and File.exist?(@ruby+'.stackdump'))
+      (BT.ruby and File.exist?(BT.ruby+'.stackdump'))
     raise CoreDumpError, "core dumped"
   end
 end
 
-main
+def yjit_enabled?
+  ENV.key?('RUBY_YJIT_ENABLE') || ENV.fetch('RUN_OPTS', '').include?('yjit') || BT.ruby.include?('yjit')
+end
+
+def zjit_enabled?
+  ENV.key?('RUBY_ZJIT_ENABLE') || ENV.fetch('RUN_OPTS', '').include?('zjit') || BT.ruby.include?('zjit')
+end
+
+exit main
diff --git a/bootstraptest/test_attr.rb b/bootstraptest/test_attr.rb