Share Maps for ElementsKind transitions

src/runtime.cc

 // Copyright 2011 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 9396 matching lines @@
       index_offset_ += delta;
     }
   }
 
   Handle<JSArray> ToArray() {
     Handle<JSArray> array = isolate_->factory()->NewJSArray(0);
     Handle<Object> length =
         isolate_->factory()->NewNumber(static_cast<double>(index_offset_));
     Handle<Map> map;
     if (fast_elements_) {
-      map = isolate_->factory()->GetFastElementsMap(Handle<Map>(array->map()));
+      map = isolate_->factory()->GetElementsTransitionMap(array,
+                                                          FAST_ELEMENTS);
     } else {
-      map = isolate_->factory()->GetSlowElementsMap(Handle<Map>(array->map()));
+      map = isolate_->factory()->GetElementsTransitionMap(array,
+                                                          DICTIONARY_ELEMENTS);
     }
     array->set_map(*map);
     array->set_length(*length);
     array->set_elements(*storage_);
     return array;
   }
 
  private:
   // Convert storage to dictionary mode.
   void SetDictionaryMode(uint32_t index) {
@@ skipping 470 matching lines @@
 }
 
 
 // Move contents of argument 0 (an array) to argument 1 (an array)
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MoveArrayContents) {
   ASSERT(args.length() == 2);
   CONVERT_CHECKED(JSArray, from, args[0]);
   CONVERT_CHECKED(JSArray, to, args[1]);
   FixedArrayBase* new_elements = from->elements();
   MaybeObject* maybe_new_map;
+  ElementsKind elements_kind;
   if (new_elements->map() == isolate->heap()->fixed_array_map() ||
       new_elements->map() == isolate->heap()->fixed_cow_array_map()) {
-    maybe_new_map = to->map()->GetFastElementsMap();
+    elements_kind = FAST_ELEMENTS;
   } else if (new_elements->map() ==
              isolate->heap()->fixed_double_array_map()) {
-    maybe_new_map = to->map()->GetFastDoubleElementsMap();
+    elements_kind = FAST_DOUBLE_ELEMENTS;
   } else {
-    maybe_new_map = to->map()->GetSlowElementsMap();
+    elements_kind = DICTIONARY_ELEMENTS;
   }
+  maybe_new_map = to->GetElementsTransitionMap(elements_kind);
   Object* new_map;
   if (!maybe_new_map->ToObject(&new_map)) return maybe_new_map;
   to->set_map(Map::cast(new_map));
   to->set_elements(new_elements);
   to->set_length(from->length());
   Object* obj;
   { MaybeObject* maybe_obj = from->ResetElements();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   from->set_length(Smi::FromInt(0));
@@ skipping 3211 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal