[runtime] Minor tweaks to LookupIterator for performance

src/ic/ic.cc

 // 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.
 
 #include "src/ic/ic.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 1388 matching lines @@
       isolate(), result,
       Runtime::GetObjectProperty(isolate(), object, key, language_mode()),
       Object);
   return result;
 }
 
 
 bool StoreIC::LookupForWrite(LookupIterator* it, Handle<Object> value,
                              JSReceiver::StoreFromKeyed store_mode) {
   // Disable ICs for non-JSObjects for now.
-  Handle<Object> receiver = it->GetReceiver();
-  if (!receiver->IsJSObject()) return false;
-  DCHECK(!Handle<JSObject>::cast(receiver)->map()->is_deprecated());
+  Handle<Object> object = it->GetReceiver();
+  if (!object->IsJSObject()) return false;
+  Handle<JSObject> receiver = Handle<JSObject>::cast(object);
+  DCHECK(!receiver->map()->is_deprecated());
 
   for (; it->IsFound(); it->Next()) {
     switch (it->state()) {
       case LookupIterator::NOT_FOUND:
       case LookupIterator::TRANSITION:
         UNREACHABLE();
       case LookupIterator::JSPROXY:
         return false;
       case LookupIterator::INTERCEPTOR: {
         Handle<JSObject> holder = it->GetHolder<JSObject>();
@@ skipping 19 matching lines @@
         if (receiver.is_identical_to(holder)) {
           it->PrepareForDataProperty(value);
           // The previous receiver map might just have been deprecated,
           // so reload it.
           update_receiver_map(receiver);
           return true;
         }
 
         // Receiver != holder.
         if (receiver->IsJSGlobalProxy()) {
-          PrototypeIterator iter(it->isolate(),
-                                 Handle<JSGlobalProxy>::cast(receiver));
+          PrototypeIterator iter(it->isolate(), receiver);
           return it->GetHolder<Object>().is_identical_to(
               PrototypeIterator::GetCurrent(iter));
         }
 
         if (it->HolderIsReceiverOrHiddenPrototype()) return false;
 
-        it->PrepareTransitionToDataProperty(value, NONE, store_mode);
+        if (it->ExtendingNonExtensible(receiver)) return false;
+        it->PrepareTransitionToDataProperty(receiver, value, NONE, store_mode);
         return it->IsCacheableTransition();
       }
     }
   }
 
-  it->PrepareTransitionToDataProperty(value, NONE, store_mode);
+  receiver = it->GetStoreTarget();
+  if (it->ExtendingNonExtensible(receiver)) return false;
+  it->PrepareTransitionToDataProperty(receiver, value, NONE, store_mode);
   return it->IsCacheableTransition();
 }
 
 
 MaybeHandle<Object> StoreIC::Store(Handle<Object> object, Handle<Name> name,
                                    Handle<Object> value,
                                    JSReceiver::StoreFromKeyed store_mode) {
   // Check if the name is trivially convertible to an index and set the element.
   uint32_t index;
   if (kind() == Code::KEYED_STORE_IC && name->AsArrayIndex(&index)) {
@@ skipping 1487 matching lines @@
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   }
 
   return *result;
 }
 }  // namespace internal
 }  // namespace v8