Array constructor can be simplified by loading context from JSFunction.

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 2639 matching lines @@
     memento_create_count->ClearFlag(HValue::kCanOverflow);
     HStoreNamedField* store = Add<HStoreNamedField>(
         allocation_site, HObjectAccess::ForAllocationSiteOffset(
             AllocationSite::kMementoCreateCountOffset), memento_create_count);
     // No write barrier needed to store a smi.
     store->SkipWriteBarrier();
   }
 }
 
 
+HInstruction* HGraphBuilder::BuildGetNativeContext(HValue* closure) {
+  // Get the global context, then the native context
+  HInstruction* context =
+      Add<HLoadNamedField>(closure, HObjectAccess::ForFunctionContextPointer());
+  HInstruction* global_object = Add<HLoadNamedField>(context,
+      HObjectAccess::ForContextSlot(Context::GLOBAL_OBJECT_INDEX));
+  HObjectAccess access = HObjectAccess::ForJSObjectOffset(
+      GlobalObject::kNativeContextOffset);
+  return Add<HLoadNamedField>(global_object, access);
+}
+
+
 HInstruction* HGraphBuilder::BuildGetNativeContext() {
   // Get the global context, then the native context
   HInstruction* global_object = Add<HGlobalObject>();
   HObjectAccess access = HObjectAccess::ForJSObjectOffset(
       GlobalObject::kNativeContextOffset);
   return Add<HLoadNamedField>(global_object, access);
 }
 
 
 HInstruction* HGraphBuilder::BuildGetArrayFunction() {
@@ skipping 39 matching lines @@
     return builder()->Add<HConstant>(map);
   }
 
   if (constructor_function_ != NULL && kind_ == GetInitialFastElementsKind()) {
     // No need for a context lookup if the kind_ matches the initial
     // map, because we can just load the map in that case.
     HObjectAccess access = HObjectAccess::ForPrototypeOrInitialMap();
     return builder()->AddLoadNamedField(constructor_function_, access);
   }
 
-  HInstruction* native_context = builder()->BuildGetNativeContext();
+  // TODO(mvstanton): we should always have a constructor function if we
+  // are creating a stub.
+  HInstruction* native_context = constructor_function_ != NULL
+      ? builder()->BuildGetNativeContext(constructor_function_)
+      : builder()->BuildGetNativeContext();
+
   HInstruction* index = builder()->Add<HConstant>(
       static_cast<int32_t>(Context::JS_ARRAY_MAPS_INDEX));
 
   HInstruction* map_array = builder()->Add<HLoadKeyed>(
       native_context, index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
 
   HInstruction* kind_index = builder()->Add<HConstant>(kind_);
 
   return builder()->Add<HLoadKeyed>(
       map_array, kind_index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
@@ skipping 8214 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal