Optimize Map/Set.prototype.forEach

src/objects-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 6939 matching lines @@
 
 template<int start_offset>
 void FlexibleBodyDescriptor<start_offset>::IterateBody(HeapObject* obj,
                                                        int object_size,
                                                        ObjectVisitor* v) {
   v->VisitPointers(HeapObject::RawField(obj, start_offset),
                    HeapObject::RawField(obj, object_size));
 }
 
 
+template<class Derived, class TableType>
+Handle<Object> OrderedHashTableIterator<Derived, TableType>::CurrentKey(
+    Handle<Derived> iterator) {
+  TableType* table(TableType::cast(iterator->table()));

[adamk, 2014/06/16 20:37:46]

The use of a raw pointer in a handlified function looks wrong. Can CurrentKey()
just be an instance method instead of a static, and operate on raw pointers? It
doesn't look like it needs to do any allocation.

[arv (Not doing code reviews), 2014/06/16 21:57:21]

Done.

+  int index = Smi::cast(iterator->index())->value();
+  Handle<Object> key(table->KeyAt(index), iterator->GetIsolate());
+  ASSERT(!key->IsTheHole());
+  return key;
+}
+
+
+Handle<Object> JSMapIterator::CurrentValue(Handle<JSMapIterator> iterator) {

[adamk, 2014/06/16 20:37:46]

Same as above, but less scary. Seems like this could be an instance method?

[arv (Not doing code reviews), 2014/06/16 21:57:20]

Done.

+  OrderedHashMap* table(OrderedHashMap::cast(iterator->table()));
+  int index = Smi::cast(iterator->index())->value();
+  Handle<Object> value(table->ValueAt(index), iterator->GetIsolate());
+  ASSERT(!value->IsTheHole());
+  return value;
+}
+
+
 #undef TYPE_CHECKER
 #undef CAST_ACCESSOR
 #undef INT_ACCESSORS
 #undef ACCESSORS
 #undef ACCESSORS_TO_SMI
 #undef SMI_ACCESSORS
 #undef SYNCHRONIZED_SMI_ACCESSORS
 #undef NOBARRIER_SMI_ACCESSORS
 #undef BOOL_GETTER
 #undef BOOL_ACCESSORS
@@ skipping 15 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_