Implement HChange support for Smis and use it in Load/StoreNameField

src/hydrogen-instructions.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 5191 matching lines @@
                   int offset, HValue* typecheck = NULL)
       : is_in_object_(is_in_object),
         field_representation_(field_representation),
         offset_(offset) {
     ASSERT(object != NULL);
     SetOperandAt(0, object);
     SetOperandAt(1, typecheck != NULL ? typecheck : object);
 
     if (FLAG_track_fields && field_representation.IsSmi()) {
       set_type(HType::Smi());
-      set_representation(Representation::Tagged());
+      set_representation(field_representation);
     } else if (FLAG_track_double_fields && field_representation.IsDouble()) {
       set_representation(field_representation);
     } else if (FLAG_track_heap_object_fields &&
                field_representation.IsHeapObject()) {
       set_type(HType::NonPrimitive());
       set_representation(Representation::Tagged());
     } else {
       set_representation(Representation::Tagged());
     }
     SetFlag(kUseGVN);
@@ skipping 373 matching lines @@
   }
 
   DECLARE_CONCRETE_INSTRUCTION(StoreNamedField)
 
   virtual Representation RequiredInputRepresentation(int index) {
     if (FLAG_track_double_fields &&
         index == 1 && field_representation_.IsDouble()) {
       return field_representation_;
     } else if (FLAG_track_fields &&
                index == 1 && field_representation_.IsSmi()) {
-      return Representation::Integer32();
+      return field_representation_;
     }
     return Representation::Tagged();
   }
   virtual void SetSideEffectDominator(GVNFlag side_effect, HValue* dominator) {
     ASSERT(side_effect == kChangesNewSpacePromotion);
     new_space_dominator_ = dominator;
   }
   virtual void PrintDataTo(StringStream* stream);
 
   HValue* object() { return OperandAt(0); }
@@ skipping 844 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_