Don't use StubType to probe the code caches.

src/objects.cc

 // Copyright 2013 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 7321 matching lines @@
   Object* new_cache;
   { MaybeObject* maybe_new_cache = cache->Put(name, code);
     if (!maybe_new_cache->ToObject(&new_cache)) return maybe_new_cache;
   }
   set_normal_type_cache(new_cache);
   return this;
 }
 
 
 Object* CodeCache::Lookup(Name* name, Code::Flags flags) {
-  if (Code::ExtractTypeFromFlags(flags) == Code::NORMAL) {
-    return LookupNormalTypeCache(name, flags);
-  } else {
-    return LookupDefaultCache(name, flags);
-  }
+  flags = Code::RemoveTypeFromFlags(flags);
+  Object* result = LookupDefaultCache(name, flags);
+  if (result->IsCode()) return result;
+  return LookupNormalTypeCache(name, flags);
 }
 
 
 Object* CodeCache::LookupDefaultCache(Name* name, Code::Flags flags) {
   FixedArray* cache = default_cache();
   int length = cache->length();
   for (int i = 0; i < length; i += kCodeCacheEntrySize) {
     Object* key = cache->get(i + kCodeCacheEntryNameOffset);
     // Skip deleted elements.
     if (key->IsNull()) continue;
     if (key->IsUndefined()) return key;
     if (name->Equals(Name::cast(key))) {
       Code* code = Code::cast(cache->get(i + kCodeCacheEntryCodeOffset));
-      if (code->flags() == flags) {
+      if (Code::RemoveTypeFromFlags(code->flags()) == flags) {
         return code;
       }
     }
   }
   return GetHeap()->undefined_value();
 }
 
 
 Object* CodeCache::LookupNormalTypeCache(Name* name, Code::Flags flags) {
   if (!normal_type_cache()->IsUndefined()) {
@@ skipping 43 matching lines @@
 // The key in the code cache hash table consists of the property name and the
 // code object. The actual match is on the name and the code flags. If a key
 // is created using the flags and not a code object it can only be used for
 // lookup not to create a new entry.
 class CodeCacheHashTableKey : public HashTableKey {
  public:
   CodeCacheHashTableKey(Name* name, Code::Flags flags)
       : name_(name), flags_(flags), code_(NULL) { }
 
   CodeCacheHashTableKey(Name* name, Code* code)
-      : name_(name),
-        flags_(code->flags()),
-        code_(code) { }
+      : name_(name), flags_(code->flags()), code_(code) { }
 
 
   bool IsMatch(Object* other) {
     if (!other->IsFixedArray()) return false;
     FixedArray* pair = FixedArray::cast(other);
     Name* name = Name::cast(pair->get(0));
     Code::Flags flags = Code::cast(pair->get(1))->flags();
     if (flags != flags_) {
       return false;
     }
@@ skipping 8732 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal