[runtime] Minor tweaks to LookupIterator for performance

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 4475 matching lines @@
   DCHECK_NE(LookupIterator::INTEGER_INDEXED_EXOTIC, it->state());
 
   Handle<JSObject> receiver = it->GetStoreTarget();
 
   // If the receiver is a JSGlobalProxy, store on the prototype (JSGlobalObject)
   // instead. If the prototype is Null, the proxy is detached.
   if (receiver->IsJSGlobalProxy()) return Just(true);
 
   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()));
   }
 
   if (it->IsElement()) {
     if (receiver->IsJSArray()) {
       Handle<JSArray> array = Handle<JSArray>::cast(receiver);
       if (JSArray::WouldChangeReadOnlyLength(array, it->index())) {
         RETURN_FAILURE(array->GetIsolate(), should_throw,
@@ skipping 12 matching lines @@
       }
     }
 
     Maybe<bool> result = JSObject::AddDataElement(receiver, it->index(), value,
                                                   attributes, should_throw);
     JSObject::ValidateElements(receiver);
     return result;
   } 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()) {
       // TODO(verwaest): Probably should ensure this is done beforehand.
       it->InternalizeName();
       // TODO(dcarney): just populate TransitionPropertyCell here?
       JSObject::AddSlowProperty(receiver, it->name(), value, attributes);
     } else {
       // Write the property value.
       it->WriteDataValue(value);
@@ skipping 5392 matching lines @@
 
 // static
 Handle<Map> Map::PrepareForDataProperty(Handle<Map> map, int descriptor,
                                         Handle<Object> value) {
   // Dictionaries can store any property value.
   if (map->is_dictionary_map()) return map;
 
   // Migrate to the newest map before storing the property.
   map = Update(map);
 
-  Handle<DescriptorArray> descriptors(map->instance_descriptors());
-
-  if (descriptors->CanHoldValue(descriptor, *value)) return map;
+  if (map->instance_descriptors()->CanHoldValue(descriptor, *value)) return map;
 
   Isolate* isolate = map->GetIsolate();
   PropertyAttributes attributes =
-      descriptors->GetDetails(descriptor).attributes();
+      map->instance_descriptors()->GetDetails(descriptor).attributes();
   Representation representation = value->OptimalRepresentation();
   Handle<FieldType> type = value->OptimalType(isolate, representation);
 
   return ReconfigureProperty(map, descriptor, kData, attributes, representation,
                              type, FORCE_FIELD);
 }
 
 
 Handle<Map> Map::TransitionToDataProperty(Handle<Map> map, Handle<Name> name,
                                           Handle<Object> value,
@@ skipping 10023 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8