Use mutable heapnumbers to store doubles in fields.

src/ic.h

 // 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 27 matching lines @@
 // 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(KeyedLoadIC_MissForceGeneric)                   \
   ICU(CallIC_Miss)                                    \
   ICU(KeyedCallIC_Miss)                               \
   ICU(StoreIC_Miss)                                   \
   ICU(StoreIC_ArrayLength)                            \
+  ICU(StoreIC_Slow)                                   \
   ICU(SharedStoreIC_ExtendStorage)                    \
   ICU(KeyedStoreIC_Miss)                              \
   ICU(KeyedStoreIC_MissForceGeneric)                  \
   ICU(KeyedStoreIC_Slow)                              \
   /* Utilities for IC stubs. */                       \
   ICU(StoreCallbackProperty)                          \
   ICU(LoadPropertyWithInterceptorOnly)                \
   ICU(LoadPropertyWithInterceptorForLoad)             \
   ICU(LoadPropertyWithInterceptorForCall)             \
   ICU(KeyedLoadPropertyWithInterceptor)               \
@@ skipping 439 matching lines @@
 };
 
 
 class StoreIC: public IC {
  public:
   StoreIC(FrameDepth depth, Isolate* isolate) : IC(depth, isolate) {
     ASSERT(target()->is_store_stub() || target()->is_keyed_store_stub());
   }
 
   // Code generators for stub routines. Only called once at startup.
+  static void GenerateSlow(MacroAssembler* masm);
   static void GenerateInitialize(MacroAssembler* masm) { GenerateMiss(masm); }
   static void GenerateMiss(MacroAssembler* masm);
   static void GenerateMegamorphic(MacroAssembler* masm,
                                   StrictModeFlag strict_mode);
   static void GenerateNormal(MacroAssembler* masm);
   static void GenerateGlobalProxy(MacroAssembler* masm,
                                   StrictModeFlag strict_mode);
 
   MUST_USE_RESULT MaybeObject* Store(
       State state,
@@ skipping 293 matching lines @@
 void PatchInlinedSmiCode(Address address, InlinedSmiCheck check);
 
 DECLARE_RUNTIME_FUNCTION(MaybeObject*, KeyedLoadIC_MissFromStubFailure);
 DECLARE_RUNTIME_FUNCTION(MaybeObject*, KeyedStoreIC_MissFromStubFailure);
 DECLARE_RUNTIME_FUNCTION(MaybeObject*, CompareNilIC_Miss);
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IC_H_