From 4ebab10bf5ac061bd71df8db2fd7fea61be658c0 Mon Sep 17 00:00:00 2001
From: normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 8 Dec 2015 01:46:45 +0000
Subject: compile optimized case dispatch for nil/true/false

nil/true/false are special literals just like floats, integers,
literal strings, and symbols.  Optimize when statements with
them by using a jump table, too.

target 0: a (ruby 2.3.0dev (2015-12-08 trunk 52928) [x86_64-linux]) at "/home/ew/rrrr/b/ruby"
target 1: b (ruby 2.3.0dev (2015-12-08 master 52928) [x86_64-linux]) at "/home/ew/ruby/b/ruby"

benchmark results:
minimum results in each 5 measurements.
Execution time (sec)
name	a	b
loop_whileloop2	0.102	0.103
vm2_case_lit*	1.657	0.549

Speedup ratio: compare with the result of `a' (greater is better)
name	b
loop_whileloop2	0.988
vm2_case_lit*	3.017

* benchmark/bm_vm2_case_lit.rb: new benchmark
* compile.c (case_when_optimizable_literal): add nil/true/false
* insns.def (opt_case_dispatch): ditto
* vm.c (vm_redefinition_check_flag): ditto
* vm.c (vm_init_redefined_flag): ditto
* vm_core.h: ditto
* object.c (InitVM_Object): define === explicitly for nil/true/false
* test/ruby/test_case.rb (test_deoptimize_nil): new test
* test/ruby/test_optimization.rb (test_opt_case_dispatch): update
  (test_eqq): new test
  [ruby-core:71923] [Feature #11769]
  Original patch by Aaron Patterson <tenderlove@ruby-lang.org>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52931 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 insns.def | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'insns.def')

diff --git a/insns.def b/insns.def
index c8088919c5..3c4d98073b 100644
--- a/insns.def
+++ b/insns.def
@@ -1264,6 +1264,9 @@ opt_case_dispatch
 	    key = FIXABLE(ival) ? LONG2FIX((long)ival) : rb_dbl2big(ival);
 	}
       }
+      case T_TRUE:
+      case T_FALSE:
+      case T_NIL:
       case T_SYMBOL: /* fall through */
       case T_FIXNUM:
       case T_BIGNUM:
@@ -1273,6 +1276,9 @@ opt_case_dispatch
 				   FIXNUM_REDEFINED_OP_FLAG |
 				   FLOAT_REDEFINED_OP_FLAG |
 				   BIGNUM_REDEFINED_OP_FLAG |
+				   NIL_REDEFINED_OP_FLAG    |
+				   TRUE_REDEFINED_OP_FLAG   |
+				   FALSE_REDEFINED_OP_FLAG  |
 				   STRING_REDEFINED_OP_FLAG)) {
 	    st_data_t val;
 	    if (st_lookup(RHASH_TBL_RAW(hash), key, &val)) {
-- 
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