Types: cache lub bitset to avoid heap access

test/cctest/test-types.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 172 matching lines @@
   static bool IsConstant(Type* t) { return IsTagged(t, 1); }
   static bool IsUnion(Type* t) { return IsTagged(t, 2); }
 
   static ZoneList<void*>* AsTagged(Type* t) {
     return reinterpret_cast<ZoneList<void*>*>(t);
   }
   static int AsBitset(Type* t) {
     return static_cast<int>(reinterpret_cast<intptr_t>(t) >> 1);
   }
   static Map* AsClass(Type* t) {
-    return *reinterpret_cast<Map**>(AsTagged(t)->at(1));
+    return *reinterpret_cast<Map**>(AsTagged(t)->at(2));
   }
   static Object* AsConstant(Type* t) {
-    return *reinterpret_cast<Object**>(AsTagged(t)->at(1));
+    return *reinterpret_cast<Object**>(AsTagged(t)->at(2));
   }
   static ZoneList<Type*>* AsUnion(Type* t) {
     return reinterpret_cast<ZoneList<Type*>*>(AsTagged(t));
   }
 
   static Zone* ToRegion(Zone* zone, Isolate* isolate) { return zone; }
 };
 
 
 struct HeapRep {
@@ skipping 661 matching lines @@
   ZoneTests().Intersect();
   HeapTests().Intersect();
 }
 
 
 TEST(Convert) {
   CcTest::InitializeVM();
   ZoneTests().Convert<HeapType, Handle<HeapType>, Isolate, HeapRep>();
   HeapTests().Convert<Type, Type*, Zone, ZoneRep>();
 }