Make setting length on arrays faster.

src/ic.h

 // Copyright 2006-2009 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 27 matching lines @@
 enum DictionaryCheck { CHECK_DICTIONARY, DICTIONARY_CHECK_DONE };
 
 
 // IC_UTIL_LIST defines all utility functions called from generated
 // inline caching code. The argument for the macro, ICU, is the function name.
 #define IC_UTIL_LIST(ICU)                             \
   ICU(LoadIC_Miss)                                    \
   ICU(KeyedLoadIC_Miss)                               \
   ICU(CallIC_Miss)                                    \
   ICU(StoreIC_Miss)                                   \
+  ICU(StoreIC_ArrayLength)                            \
   ICU(SharedStoreIC_ExtendStorage)                    \
   ICU(KeyedStoreIC_Miss)                              \
   /* Utilities for IC stubs. */                       \
   ICU(LoadCallbackProperty)                           \
   ICU(StoreCallbackProperty)                          \
   ICU(LoadPropertyWithInterceptorOnly)                \
   ICU(LoadPropertyWithInterceptorForLoad)             \
   ICU(LoadPropertyWithInterceptorForCall)             \
   ICU(KeyedLoadPropertyWithInterceptor)               \
   ICU(StoreInterceptorProperty)
@@ skipping 293 matching lines @@
 
   Object* Store(State state,
                 Handle<Object> object,
                 Handle<String> name,
                 Handle<Object> value);
 
   // Code generators for stub routines. Only called once at startup.
   static void GenerateInitialize(MacroAssembler* masm) { GenerateMiss(masm); }
   static void GenerateMiss(MacroAssembler* masm);
   static void GenerateMegamorphic(MacroAssembler* masm);
+  static void GenerateArrayLength(MacroAssembler* masm);
 
  private:
   // Update the inline cache and the global stub cache based on the
   // lookup result.
   void UpdateCaches(LookupResult* lookup,
                     State state, Handle<JSObject> receiver,
                     Handle<String> name,
                     Handle<Object> value);
 
   // Stub accessors.
@@ skipping 67 matching lines @@
   // The map is the new map that the inlined code should check against.
   static bool PatchInlinedStore(Address address, Object* map);
 
   friend class IC;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IC_H_