Minimal backport of the most important parts of r12271

src/hydrogen-instructions.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1613 matching lines @@
 // polymorphic loads where the property is sometimes found in the prototype
 // chain.
 static bool PrototypeChainCanNeverResolve(
     Handle<Map> map, Handle<String> name) {
   Isolate* isolate = map->GetIsolate();
   Object* current = map->prototype();
   while (current != isolate->heap()->null_value()) {
     if (current->IsJSGlobalProxy() ||
         current->IsGlobalObject() ||
         !current->IsJSObject() ||
+        JSObject::cast(current)->map()->has_named_interceptor() ||
         JSObject::cast(current)->IsAccessCheckNeeded() ||
         !JSObject::cast(current)->HasFastProperties()) {
       return false;
     }
 
     LookupResult lookup(isolate);
     JSObject::cast(current)->map()->LookupInDescriptors(NULL, *name, &lookup);
     if (lookup.IsFound()) {
       if (lookup.type() != MAP_TRANSITION) return false;
     } else if (!lookup.IsCacheable()) {
@@ skipping 34 matching lines @@
           } else {
             SetGVNFlag(kDependsOnBackingStoreFields);
           }
           types_.Add(types->at(i), zone);
           break;
         }
         case CONSTANT_FUNCTION:
           types_.Add(types->at(i), zone);
           break;
         case MAP_TRANSITION:
-          if (PrototypeChainCanNeverResolve(map, name)) {
+          if (!map->has_named_interceptor() &&
+              PrototypeChainCanNeverResolve(map, name)) {
             negative_lookups.Add(types->at(i), zone);
           }
           break;
         default:
           break;
       }
     } else if (lookup.IsCacheable()) {
-      if (PrototypeChainCanNeverResolve(map, name)) {
+      if (!map->has_named_interceptor() &&
+          PrototypeChainCanNeverResolve(map, name)) {
         negative_lookups.Add(types->at(i), zone);
       }
     }
   }
 
   bool need_generic =
       (types->length() != negative_lookups.length() + types_.length());
   if (!need_generic && FLAG_deoptimize_uncommon_cases) {
     SetFlag(kUseGVN);
     for (int i = 0; i < negative_lookups.length(); i++) {
@@ skipping 813 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal