Starting using GlobalDictionary for global objects instead of NameDictionary.

src/runtime/runtime-object.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug.h"
 #include "src/messages.h"
@@ skipping 580 matching lines @@
   // prototype including own lookups.
   //
   // Additionally, we need to make sure that we do not cache results
   // for objects that require access checks.
   if (receiver_obj->IsJSObject()) {
     if (!receiver_obj->IsJSGlobalProxy() &&
         !receiver_obj->IsAccessCheckNeeded() && key_obj->IsName()) {
       DisallowHeapAllocation no_allocation;
       Handle<JSObject> receiver = Handle<JSObject>::cast(receiver_obj);
       Handle<Name> key = Handle<Name>::cast(key_obj);
-      if (!receiver->HasFastProperties()) {
+      if (receiver->IsGlobalObject()) {
+        // Attempt dictionary lookup.
+        GlobalDictionary* dictionary = receiver->global_dictionary();
+        int entry = dictionary->FindEntry(key);
+        if ((entry != GlobalDictionary::kNotFound) &&
+            (dictionary->DetailsAt(entry).type() == DATA)) {
+          Object* value = dictionary->ValueAt(entry);
+          DCHECK(value->IsPropertyCell());
+          value = PropertyCell::cast(value)->value();
+          if (!value->IsTheHole()) return value;
+          // If value is the hole (meaning, absent) do the general lookup.
+        }
+      } else if (!receiver->HasFastProperties()) {
         // Attempt dictionary lookup.
         NameDictionary* dictionary = receiver->property_dictionary();
         int entry = dictionary->FindEntry(key);
         if ((entry != NameDictionary::kNotFound) &&
             (dictionary->DetailsAt(entry).type() == DATA)) {
           Object* value = dictionary->ValueAt(entry);
-          if (!receiver->IsGlobalObject()) return value;
-          DCHECK(value->IsPropertyCell());
-          value = PropertyCell::cast(value)->value();
-          if (!value->IsTheHole()) return value;
-          // If value is the hole (meaning, absent) do the general lookup.
+          return value;
         }
       }
     } else if (key_obj->IsSmi()) {
       // JSObject without a name key. If the key is a Smi, check for a
       // definite out-of-bounds access to elements, which is a strong indicator
       // that subsequent accesses will also call the runtime. Proactively
       // transition elements to FAST_*_ELEMENTS to avoid excessive boxing of
       // doubles for those future calls in the case that the elements would
       // become FAST_DOUBLE_ELEMENTS.
       Handle<JSObject> js_object = Handle<JSObject>::cast(receiver_obj);
@@ skipping 955 matching lines @@
   CONVERT_PROPERTY_ATTRIBUTES_CHECKED(attrs, 3);
 
   RETURN_FAILURE_ON_EXCEPTION(
       isolate,
       JSObject::DefineAccessor(object, name, isolate->factory()->null_value(),
                                setter, attrs));
   return isolate->heap()->undefined_value();
 }
 }  // namespace internal
 }  // namespace v8