Remove HCheckSmi, LCheckSmi and rename LCheckSmiAndReturn to LCheckSmi.

src/code-stubs-hydrogen.cc

 // 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 624 matching lines @@
   LoopBuilder builder(this,
                       context(),
                       LoopBuilder::kPostIncrement);
   HValue* start = graph()->GetConstant0();
   HValue* key = builder.BeginBody(start, length, Token::LT);
   HInstruction* argument_elements = AddInstruction(
       new(zone()) HArgumentsElements(false));
   HInstruction* argument = AddInstruction(new(zone()) HAccessArgumentsAt(
       argument_elements, length, key));
 
-  // Checks to prevent incompatible stores
-  if (IsFastSmiElementsKind(kind)) {
-    AddInstruction(new(zone()) HCheckSmi(argument));
-  }
-
   AddInstruction(new(zone()) HStoreKeyed(elements, key, argument, kind));
   builder.EndBody();
   return new_object;
 }
 
 
 Handle<Code> ArrayNArgumentsConstructorStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
@@ skipping 17 matching lines @@
       ? graph()->GetConstant1()
       : graph()->GetConstantUndefined();
 }
 
 
 Handle<Code> CompareNilICStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 } }  // namespace v8::internal