Reimplemented the KeyedLookupCache to speed up access.

src/heap.h

 // Copyright 2006-2008 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 108 matching lines @@
   V(Proxy, prototype_accessors)                         \
   V(Dictionary, code_stubs)                             \
   V(Dictionary, non_monomorphic_cache)                  \
   V(Code, js_entry_code)                                \
   V(Code, js_construct_entry_code)                      \
   V(Code, c_entry_code)                                 \
   V(Code, c_entry_debug_break_code)                     \
   V(FixedArray, number_string_cache)                    \
   V(FixedArray, single_character_string_cache)          \
   V(FixedArray, natives_source_cache)                   \
-  V(Object, keyed_lookup_cache)                         \
   V(Object, last_script_id)
 
 
 #define ROOT_LIST(V)                                  \
   STRONG_ROOT_LIST(V)                                 \
   V(Object, symbol_table)
 
 #define SYMBOL_LIST(V)                                                   \
   V(Array_symbol, "Array")                                               \
   V(Object_symbol, "Object")                                             \
@@ skipping 553 matching lines @@
   static inline AllocationSpace TargetSpaceId(InstanceType type);
 
   // Sets the stub_cache_ (only used when expanding the dictionary).
   static void set_code_stubs(Dictionary* value) { code_stubs_ = value; }
 
   // Sets the non_monomorphic_cache_ (only used when expanding the dictionary).
   static void set_non_monomorphic_cache(Dictionary* value) {
     non_monomorphic_cache_ = value;
   }
 
-  // Gets, sets and clears the lookup cache used for keyed access.
-  static inline Object* GetKeyedLookupCache();
-  static inline void SetKeyedLookupCache(LookupCache* cache);
-  static inline void ClearKeyedLookupCache();
-
   // Update the next script id.
   static inline void SetLastScriptId(Object* last_script_id);
 
 #ifdef DEBUG
   static void Print();
   static void PrintHandles();
 
   // Verify the heap is in its normal state before or after a GC.
   static void Verify();
 
@@ skipping 415 matching lines @@
   // Perform all necessary shutdown (destruction) work.
   void Shutdown();
 
   // Space iterator for iterating all the spaces.
   SpaceIterator* space_iterator_;
   // Object iterator for the space currently being iterated.
   ObjectIterator* object_iterator_;
 };
 
 
+// Cache for mapping (map, property name) into field offset.
+// Cleared at startup and prior to mark sweep collection.
+class KeyedLookupCache {
+ public:
+  // Lookup field offset for (map, name). If absent, -1 is returned.
+  static int Lookup(Map* map, String* name);
+
+  // Update an element in the cache.
+  static void Update(Map* map, String* name, int field_offset);
+
+  // Clear the cache.
+  static void Clear();
+ private:
+  inline static int Hash(Map* map, String* name);
+  static const int kLength = 128;
+  struct Key {
+    Map* map;
+    String* name;
+  };
+  static Key keys_[kLength];
+  static int field_offsets_[kLength];
+};
+
+
 // ----------------------------------------------------------------------------
 // Marking stack for tracing live objects.
 
 class MarkingStack {
  public:
   void Initialize(Address low, Address high) {
     top_ = low_ = reinterpret_cast<HeapObject**>(low);
     high_ = reinterpret_cast<HeapObject**>(high);
     overflowed_ = false;
   }
@@ skipping 156 matching lines @@
   int marked_count_;
 
   // The count from the end of the previous full GC.  Will be zero if there
   // was no previous full GC.
   int previous_marked_count_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_