Grouping all map creation code.

src/objects-inl.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 3635 matching lines @@
   ASSERT(undefined->IsUndefined());
   WRITE_FIELD(this, kInstanceDescriptorsOrBackPointerOffset, undefined);
 }
 
 
 void Map::SetBackPointer(Object* value, WriteBarrierMode mode) {
   ASSERT(instance_type() >= FIRST_JS_RECEIVER_TYPE);
   ASSERT((value->IsUndefined() && GetBackPointer()->IsMap()) ||
          (value->IsMap() && GetBackPointer()->IsUndefined()));
   Object* object = READ_FIELD(this, kInstanceDescriptorsOrBackPointerOffset);
-  if (object->IsMap()) {
+  if (object->IsDescriptorArray()) {
+    DescriptorArray::cast(object)->set_back_pointer_storage(value);
+  } else {
     WRITE_FIELD(this, kInstanceDescriptorsOrBackPointerOffset, value);
     CONDITIONAL_WRITE_BARRIER(
         GetHeap(), this, kInstanceDescriptorsOrBackPointerOffset, value, mode);
-  } else {
-    DescriptorArray::cast(object)->set_back_pointer_storage(value);
   }
 }
 
 
 // Can either be Smi (no transitions), normal transition array, or a transition
 // array with the header overwritten as a Smi (thus iterating).
 TransitionArray* Map::unchecked_transition_array() {
   ASSERT(HasTransitionArray());
   Object* object = *HeapObject::RawField(instance_descriptors(),
                                          DescriptorArray::kTransitionsOffset);
@@ skipping 622 matching lines @@
 
     Map* current_map = initial_map;
     ElementsKind kind = current_map->elements_kind();
     ASSERT(kind == GetInitialFastElementsKind());
     maps->set(kind, current_map);
     for (int i = GetSequenceIndexFromFastElementsKind(kind) + 1;
          i < kFastElementsKindCount; ++i) {
       Map* new_map;
       ElementsKind next_kind = GetFastElementsKindFromSequenceIndex(i);
       MaybeObject* maybe_new_map =
-          current_map->CreateNextElementsTransition(next_kind);
+          current_map->CopyAsElementsKind(next_kind, INSERT_TRANSITION);
       if (!maybe_new_map->To(&new_map)) return maybe_new_map;
       maps->set(next_kind, new_map);
       current_map = new_map;
     }
     global_context->set_js_array_maps(maps);
   }
   set_initial_map(initial_map);
   return this;
 }
 
@@ skipping 1007 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_