Fix representation requirement in HReturn.

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 1563 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 class HReturn V8_FINAL : public HTemplateControlInstruction<0, 3> {
  public:
   DECLARE_INSTRUCTION_WITH_CONTEXT_FACTORY_P2(HReturn, HValue*, HValue*);
   DECLARE_INSTRUCTION_WITH_CONTEXT_FACTORY_P1(HReturn, HValue*);
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
+    // TODO(titzer): require an Int32 input for faster returns.
+    if (index == 2) return Representation::Smi();
     return Representation::Tagged();
   }
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
   HValue* value() { return OperandAt(0); }
   HValue* context() { return OperandAt(1); }
   HValue* parameter_count() { return OperandAt(2); }
 
   DECLARE_CONCRETE_INSTRUCTION(Return)
@@ skipping 5959 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_