Add MEGAMORPHIC state support for KeyedLoadIC

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/runtime/runtime.h"
@@ skipping 583 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()) {
-        // Attempt to use lookup cache.
-        Handle<Map> receiver_map(receiver->map(), isolate);
-        KeyedLookupCache* keyed_lookup_cache = isolate->keyed_lookup_cache();
-        int index = keyed_lookup_cache->Lookup(receiver_map, key);
-        if (index != -1) {
-          // Doubles are not cached, so raw read the value.
-          return receiver->RawFastPropertyAt(
-              FieldIndex::ForKeyedLookupCacheIndex(*receiver_map, index));
-        }
-        // Lookup cache miss.  Perform lookup and update the cache if
-        // appropriate.
-        LookupIterator it(receiver, key, LookupIterator::OWN);
-        if (it.state() == LookupIterator::DATA &&
-            it.property_details().type() == DATA) {
-          FieldIndex field_index = it.GetFieldIndex();
-          // Do not track double fields in the keyed lookup cache. Reading
-          // double values requires boxing.
-          if (!it.representation().IsDouble()) {
-            keyed_lookup_cache->Update(receiver_map, key,
-                                       field_index.GetKeyedLookupCacheIndex());
-          }
-          AllowHeapAllocation allow_allocation;
-          return *JSObject::FastPropertyAt(receiver, it.representation(),
-                                           field_index);
-        }
-      } 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;
           value = PropertyCell::cast(value)->value();
           if (!value->IsTheHole()) return value;
           // If value is the hole (meaning, absent) do the general lookup.
@@ skipping 995 matching lines @@
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, setter, 2);
 
   RETURN_FAILURE_ON_EXCEPTION(
       isolate,
       JSObject::DefineAccessor(object, name, isolate->factory()->null_value(),
                                setter, NONE));
   return isolate->heap()->undefined_value();
 }
 }
 }  // namespace v8::internal