Reland "Turn ElementsTransitionAndStore stub into a HydrogenCodeStub".

src/hydrogen.cc

 // Copyright 2013 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 1205 matching lines @@
   cow_checker.Else();
 
   environment()->Push(elements);
 
   cow_checker.End();
 
   return environment()->Pop();
 }
 
 
+void HGraphBuilder::BuildTransitionElementsKind(HValue* object,
+                                                HValue* map,
+                                                ElementsKind from_kind,
+                                                ElementsKind to_kind,
+                                                bool is_jsarray) {
+  ASSERT(!IsFastHoleyElementsKind(from_kind) ||
+         IsFastHoleyElementsKind(to_kind));
+
+  if (AllocationSite::GetMode(from_kind, to_kind) == TRACK_ALLOCATION_SITE) {
+    Add<HTrapAllocationMemento>(object);
+  }
+
+  if (!IsSimpleMapChangeTransition(from_kind, to_kind)) {
+    HInstruction* elements = AddLoadElements(object);
+
+    HInstruction* empty_fixed_array = Add<HConstant>(
+        isolate()->factory()->empty_fixed_array(), Representation::Tagged());
+
+    IfBuilder if_builder(this);
+
+    if_builder.IfNot<HCompareObjectEqAndBranch>(elements, empty_fixed_array);
+
+    if_builder.Then();
+
+    HInstruction* elements_length = AddLoadFixedArrayLength(elements);
+
+    HInstruction* array_length = is_jsarray
+        ? AddLoad(object, HObjectAccess::ForArrayLength(),
+                  NULL, Representation::Smi())
+        : elements_length;
+    array_length->set_type(HType::Smi());
+
+    BuildGrowElementsCapacity(object, elements, from_kind, to_kind,
+                              array_length, elements_length);
+
+    if_builder.End();
+  }
+
+  AddStore(object, HObjectAccess::ForMap(), map);
+}
+
+
 HInstruction* HGraphBuilder::BuildUncheckedMonomorphicElementAccess(
     HValue* object,
     HValue* key,
     HValue* val,
     HCheckMaps* mapcheck,
     bool is_js_array,
     ElementsKind elements_kind,
     bool is_store,
     LoadKeyedHoleMode load_mode,
     KeyedAccessStoreMode store_mode) {
@@ skipping 8758 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal