Optimize dynamic string interpolation for symbol/true/false/nil/0-9

This provides a significant speedup for symbol, true, false,
nil, and 0-9, class/module, and a small speedup in most other cases.

Speedups (using included benchmarks):
:symbol        :: 60%
0-9            :: 50%
Class/Module   :: 50%
nil/true/false :: 20%
integer        :: 10%
[]             :: 10%
""             :: 3%

One reason this approach is faster is it reduces the number of
VM instructions for each interpolated value.

Initial idea, approach, and benchmarks from Eric Wong. I applied
the same approach against the master branch, updating it to handle
the significant internal changes since this was first proposed 4
years ago (such as CALL_INFO/CALL_CACHE -> CALL_DATA). I also
expanded it to optimize true/false/nil/0-9/class/module, and added
handling of missing methods, refined methods, and RUBY_DEBUG.

This renames the tostring insn to anytostring, and adds an
objtostring insn that implements the optimization. This requires
making a few functions non-static, and adding some non-static
functions.

This disables 4 YJIT tests.  Those tests should be reenabled after
YJIT optimizes the new objtostring insn.

Implements [Feature #13715]

Co-authored-by: Eric Wong <e@80x24.org>
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
Co-authored-by: Yusuke Endoh <mame@ruby-lang.org>
Co-authored-by: Koichi Sasada <ko1@atdot.net>

1 files changed, 18 insertions, 2 deletions

diff --git a/insns.def b/insns.def
index 371361512f..f759c1a5c5 100644
--- a/insns.def
+++ b/insns.def
@@ -381,9 +381,10 @@ concatstrings
     val = rb_str_concat_literals(num, STACK_ADDR_FROM_TOP(num));
 }
 
-/* push the result of to_s. */
+/* Convert the result to string if not already a string.
+   This is used as a backup if to_s does not return a string. */
 DEFINE_INSN
-tostring
+anytostring
 ()
 (VALUE val, VALUE str)
 (VALUE val)
@@ -781,6 +782,21 @@ opt_send_without_block
     }
 }
 
+/* Convert object to string using to_s or equivalent. */
+DEFINE_INSN
+objtostring
+(CALL_DATA cd)
+(VALUE recv)
+(VALUE val)
+// attr bool leaf = false;
+{
+    val = vm_objtostring(GET_ISEQ(), recv, cd);
+
+    if (val == Qundef) {
+        CALL_SIMPLE_METHOD();
+    }
+}
+
 DEFINE_INSN
 opt_str_freeze
 (VALUE str, CALL_DATA cd)