[runtime] Minor tweaks to LookupIterator for performance

BUG=

Review URL: https://codereview.chromium.org/1702443002

Cr-Commit-Position: refs/heads/master@{#34024}

src/ic/ic.cc

@@ -1406,9 +1406,10 @@ MaybeHandle<Object> KeyedLoadIC::Load(Handle<Object> object,
 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()) {
@@ -1448,21 +1449,23 @@ bool StoreIC::LookupForWrite(LookupIterator* it, Handle<Object> value,
 
         // 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();
 }
 

src/lookup.cc

@@ -122,9 +122,10 @@ Handle<Map> LookupIterator::GetReceiverMap() const {
 
 Handle<JSObject> LookupIterator::GetStoreTarget() const {
   if (receiver_->IsJSGlobalProxy()) {
-    PrototypeIterator iter(isolate(), Handle<JSGlobalProxy>::cast(receiver_));
-    if (iter.IsAtEnd()) return Handle<JSGlobalProxy>::cast(receiver_);
-    return PrototypeIterator::GetCurrent<JSGlobalObject>(iter);
+    Object* prototype = JSGlobalProxy::cast(*receiver_)->map()->prototype();
+    if (!prototype->IsNull()) {
+      return handle(JSGlobalObject::cast(prototype), isolate_);
+    }
   }
   return Handle<JSObject>::cast(receiver_);
 }
@@ -232,25 +233,18 @@ void LookupIterator::ReconfigureDataProperty(Handle<Object> value,
 #endif
 }
 
-
+// Can only be called when the receiver is a JSObject. JSProxy has to be handled
+// via a trap. Adding properties to primitive values is not observable.
 void LookupIterator::PrepareTransitionToDataProperty(
-    Handle<Object> value, PropertyAttributes attributes,
-    Object::StoreFromKeyed store_mode) {
+    Handle<JSObject> receiver, Handle<Object> value,
+    PropertyAttributes attributes, Object::StoreFromKeyed store_mode) {
+  DCHECK(receiver.is_identical_to(GetStoreTarget()));
   if (state_ == TRANSITION) return;
   DCHECK(state_ != LookupIterator::ACCESSOR ||
          (GetAccessors()->IsAccessorInfo() &&
           AccessorInfo::cast(*GetAccessors())->is_special_data_property()));
   DCHECK_NE(INTEGER_INDEXED_EXOTIC, state_);
   DCHECK(state_ == NOT_FOUND || !HolderIsReceiverOrHiddenPrototype());
-  // Can only be called when the receiver is a JSObject. JSProxy has to be
-  // handled via a trap. Adding properties to primitive values is not
-  // observable.
-  Handle<JSObject> receiver = GetStoreTarget();
-
-  if (!isolate()->IsInternallyUsedPropertyName(name()) &&
-      !receiver->map()->is_extensible()) {
-    return;
-  }
 
   auto transition = Map::TransitionToDataProperty(
       handle(receiver->map(), isolate_), name_, value, attributes, store_mode);
@@ -270,11 +264,11 @@ void LookupIterator::PrepareTransitionToDataProperty(
   }
 }
 
-
-void LookupIterator::ApplyTransitionToDataProperty() {
+void LookupIterator::ApplyTransitionToDataProperty(Handle<JSObject> receiver) {
   DCHECK_EQ(TRANSITION, state_);
 
-  Handle<JSObject> receiver = GetStoreTarget();
+  DCHECK(receiver.is_identical_to(GetStoreTarget()));
+
   if (receiver->IsJSGlobalObject()) return;
   holder_ = receiver;
   Handle<Map> transition = transition_map();

src/lookup.h

@@ -210,17 +210,23 @@ class LookupIterator final BASE_EMBEDDED {
   bool HasAccess() const;
 
   /* PROPERTY */
+  bool ExtendingNonExtensible(Handle<JSObject> receiver) {
+    DCHECK(receiver.is_identical_to(GetStoreTarget()));
+    return !receiver->map()->is_extensible() &&
+           (IsElement() || !isolate_->IsInternallyUsedPropertyName(name_));
+  }
   void PrepareForDataProperty(Handle<Object> value);
-  void PrepareTransitionToDataProperty(Handle<Object> value,
+  void PrepareTransitionToDataProperty(Handle<JSObject> receiver,
+                                       Handle<Object> value,
                                        PropertyAttributes attributes,
                                        Object::StoreFromKeyed store_mode);
   bool IsCacheableTransition() {
-    if (state_ != TRANSITION) return false;
+    DCHECK_EQ(TRANSITION, state_);
     return transition_->IsPropertyCell() ||
            (!transition_map()->is_dictionary_map() &&
             transition_map()->GetBackPointer()->IsMap());
   }
-  void ApplyTransitionToDataProperty();
+  void ApplyTransitionToDataProperty(Handle<JSObject> receiver);
   void ReconfigureDataProperty(Handle<Object> value,
                                PropertyAttributes attributes);
   void Delete();

src/objects.cc

@@ -4606,8 +4606,7 @@ Maybe<bool> Object::AddDataProperty(LookupIterator* it, Handle<Object> value,
 
   Isolate* isolate = it->isolate();
 
-  if (!receiver->map()->is_extensible() &&
-      (it->IsElement() || !isolate->IsInternallyUsedPropertyName(it->name()))) {
+  if (it->ExtendingNonExtensible(receiver)) {
     RETURN_FAILURE(
         isolate, should_throw,
         NewTypeError(MessageTemplate::kObjectNotExtensible, it->GetName()));
@@ -4640,9 +4639,10 @@ Maybe<bool> Object::AddDataProperty(LookupIterator* it, Handle<Object> value,
   } else {
     // Migrate to the most up-to-date map that will be able to store |value|
     // under it->name() with |attributes|.
-    it->PrepareTransitionToDataProperty(value, attributes, store_mode);
+    it->PrepareTransitionToDataProperty(receiver, value, attributes,
+                                        store_mode);
     DCHECK_EQ(LookupIterator::TRANSITION, it->state());
-    it->ApplyTransitionToDataProperty();
+    it->ApplyTransitionToDataProperty(receiver);
 
     // TODO(verwaest): Encapsulate dictionary handling better.
     if (receiver->map()->is_dictionary_map()) {