Allow boundscheck elimination to work on Smi keys.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
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@@ skipping 3642 matching lines @@
       base_ = index();
       offset_ = 0;
       scale_ = 0;
       return false;
     }
   }
 
   virtual Representation RequiredInputRepresentation(int arg_index) {
     return representation();
   }
   virtual Representation observed_input_representation(int index) {

[Jakob Kummerow, 2013/06/07 10:47:41]

You can delete the entire method (and fall back to the superclass
implementation, which returns None).

[Toon Verwaest, 2013/06/07 11:00:19]

Done.

-    return Representation::Integer32();
+    return Representation::None();
   }
 
   virtual bool IsRelationTrueInternal(NumericRelation relation,
                                       HValue* related_value,
                                       int offset = 0,
                                       int scale = 0);
 
   virtual void PrintDataTo(StringStream* stream);
   virtual void InferRepresentation(HInferRepresentation* h_infer);
 
@@ skipping 2890 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_