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

1 files changed, 13 insertions, 0 deletions

diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index 23c522612f..1c50044f7f 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -313,8 +313,11 @@ class TestRubyOptimization < Test::Unit::TestCase
     code = <<-EOF
       case foo
       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
       else
@@ -323,8 +326,11 @@ class TestRubyOptimization < Test::Unit::TestCase
     EOF
     check = {
       'foo' => :foo,
+      true => true,
+      false => false,
       :sym => :sym,
       6 => :fix,
+      nil => nil,
       0.1 => :float,
       0xffffffffffffffff => :big,
     }
@@ -349,4 +355,11 @@ class TestRubyOptimization < Test::Unit::TestCase
       end;
     end
   end
+
+  def test_eqq
+    [ nil, true, false, 0.1, :sym, 'str', 0xffffffffffffffff ].each do |v|
+      k = v.class.to_s
+      assert_redefine_method(k, '===', "assert_equal(#{v.inspect} === 0, 0)")
+    end
+  end
 end