Reland 10216 - Optimize the equality check case of ICCompare stubs.

src/type-info.cc

Index: src/type-info.cc
===================================================================
--- src/type-info.cc	(revision 10217)
+++ src/type-info.cc	(working copy)
@@ -259,6 +259,7 @@
     case CompareIC::STRINGS:
       return TypeInfo::String();
     case CompareIC::OBJECTS:
+    case CompareIC::KNOWN_OBJECTS:
       // TODO(kasperl): We really need a type for JS objects here.
       return TypeInfo::NonPrimitive();
     case CompareIC::GENERIC:
@@ -278,6 +279,19 @@
 }
 
 
+Handle<Map> TypeFeedbackOracle::GetCompareMap(CompareOperation* expr) {
+  Handle<Object> object = GetInfo(expr->id());
+  if (!object->IsCode()) return Handle<Map>::null();
+  Handle<Code> code = Handle<Code>::cast(object);
+  if (!code->is_compare_ic_stub()) return Handle<Map>::null();
+  CompareIC::State state = static_cast<CompareIC::State>(code->compare_state());
+  if (state != CompareIC::KNOWN_OBJECTS) {
+    return Handle<Map>::null();
+  }
+  return Handle<Map>(code->FindFirstMap());
+}
+
+
 TypeInfo TypeFeedbackOracle::UnaryType(UnaryOperation* expr) {
   Handle<Object> object = GetInfo(expr->id());
   TypeInfo unknown = TypeInfo::Unknown();
@@ -367,6 +381,7 @@
     case CompareIC::HEAP_NUMBERS:
       return TypeInfo::Number();
     case CompareIC::OBJECTS:
+    case CompareIC::KNOWN_OBJECTS:
       // TODO(kasperl): We really need a type for JS objects here.
       return TypeInfo::NonPrimitive();
     case CompareIC::GENERIC: