Small changes in preparation for Hydrogen-generated KeyedLoadGeneric

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include "v8.h"
 
 #include "allocation.h"
@@ skipping 7758 matching lines @@
     set_representation(Representation::Tagged());
   }
 
   int idx_;
   HForInCacheArray* index_cache_;
 };
 
 
 class HLoadFieldByIndex V8_FINAL : public HTemplateInstruction<2> {
  public:
+  DECLARE_INSTRUCTION_FACTORY_P2(HLoadFieldByIndex, HValue*, HValue*);
+
   HLoadFieldByIndex(HValue* object,
                     HValue* index) {
     SetOperandAt(0, object);
     SetOperandAt(1, index);
     SetChangesFlag(kNewSpacePromotion);
     set_representation(Representation::Tagged());
   }
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
-    return Representation::Tagged();
+    if (index == 1) {
+      return Representation::Smi();
+    } else {
+      return Representation::Tagged();
+    }
   }
 
   HValue* object() { return OperandAt(0); }
   HValue* index() { return OperandAt(1); }
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
   virtual HType CalculateInferredType() V8_OVERRIDE {
     return HType::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadFieldByIndex);
 
  private:
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_