Refactor smi tagging and untagging on IA-32.

bleeding_edge/src/ia32/stub-cache-ia32.cc

 // Copyright 2006-2009 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 218 matching lines @@
                                             Label* miss) {
   Label load_length, check_wrapper;
 
   // Check if the object is a string leaving the instance type in the
   // scratch register.
   GenerateStringCheck(masm, receiver, scratch, miss, &check_wrapper);
 
   // Load length from the string and convert to a smi.
   __ bind(&load_length);
   __ mov(eax, FieldOperand(receiver, String::kLengthOffset));
-  __ shl(eax, kSmiTagSize);
+  __ SmiTag(eax);
   __ ret(0);
 
   // Check if the object is a JSValue wrapper.
   __ bind(&check_wrapper);
   __ cmp(scratch, JS_VALUE_TYPE);
   __ j(not_equal, miss, not_taken);
 
   // Check if the wrapped value is a string and load the length
   // directly if it is.
   __ mov(receiver, FieldOperand(receiver, JSValue::kValueOffset));
@@ skipping 1688 matching lines @@
   __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal