Change codegen for literals to emit xor when literal is zero.

src/ia32/full-codegen-ia32.cc

 // Copyright 2010 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 361 matching lines @@
   UNREACHABLE();  // Not used on IA32.
 }
 
 
 void FullCodeGenerator::EffectContext::Plug(Handle<Object> lit) const {
 }
 
 
 void FullCodeGenerator::AccumulatorValueContext::Plug(
     Handle<Object> lit) const {
-  __ mov(result_register(), lit);
+  __ Set(result_register(), Immediate(lit));
 }
 
 
 void FullCodeGenerator::StackValueContext::Plug(Handle<Object> lit) const {
   // Immediates can be pushed directly.
   __ push(Immediate(lit));
 }
 
 
 void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
@@ skipping 3867 matching lines @@
   // And return.
   __ ret(0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32