Remake of the load elimination fix made earlier (r18884).

src/hydrogen.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * 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
@@ skipping 1351 matching lines @@
       ElementsKind elements_kind,
       bool is_store,
       LoadKeyedHoleMode load_mode = NEVER_RETURN_HOLE);
 
   HLoadNamedField* BuildLoadNamedField(HValue* object, HObjectAccess access);
   HInstruction* AddLoadNamedField(HValue* object, HObjectAccess access);
   HInstruction* AddLoadStringInstanceType(HValue* string);
   HInstruction* AddLoadStringLength(HValue* string);
   HStoreNamedField* AddStoreMapNoWriteBarrier(HValue* object, HValue* map) {
     HStoreNamedField* store_map = Add<HStoreNamedField>(
-        object, HObjectAccess::ForMap(), map, INITIALIZING_STORE);
+        object, HObjectAccess::ForMap(), map);
     store_map->SkipWriteBarrier();
     return store_map;
   }
   HStoreNamedField* AddStoreMapConstant(HValue* object, Handle<Map> map);
   HStoreNamedField* AddStoreMapConstantNoWriteBarrier(HValue* object,
                                                       Handle<Map> map) {
     HStoreNamedField* store_map = AddStoreMapConstant(object, map);
     store_map->SkipWriteBarrier();
     return store_map;
   }
@@ skipping 920 matching lines @@
       if (IsArrayLength()) {
         *access = HObjectAccess::ForArrayLength(map()->elements_kind());
         return true;
       }
       int offset;
       if (Accessors::IsJSObjectFieldAccessor(type_, name_, &offset)) {
         if (type_->Is(HeapType::String())) {
           ASSERT(name_->Equals(isolate()->heap()->length_string()));
           *access = HObjectAccess::ForStringLength();
         } else {
-          *access = HObjectAccess::ForJSObjectOffset(offset);
+          *access = HObjectAccess::ForJSObjectOffsetUnsafe(offset);

[Toon Verwaest, 2014/02/03 13:51:32]

Use map()

[Igor Sheludko, 2014/02/03 17:57:05]

Done.

         }
         return true;
       }
       return false;
     }
 
     bool has_holder() { return !holder_.is_null(); }
 
     LookupResult* lookup() { return &lookup_; }
     Handle<JSObject> holder() { return holder_; }
@@ skipping 392 matching lines @@
   }
 
  private:
   HGraphBuilder* builder_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_