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

src/ia32/lithium-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 922 matching lines @@
     __ sub(ToRegister(left), ToOperand(right));
   }
   if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
     DeoptimizeIf(overflow, instr->environment());
   }
 }
 
 
 void LCodeGen::DoConstantI(LConstantI* instr) {
   ASSERT(instr->result()->IsRegister());
-  __ mov(ToRegister(instr->result()), instr->value());
+  __ Set(ToRegister(instr->result()), Immediate(instr->value()));
 }
 
 
 void LCodeGen::DoConstantD(LConstantD* instr) {
   ASSERT(instr->result()->IsDoubleRegister());
   XMMRegister res = ToDoubleRegister(instr->result());
   double v = instr->value();
   // Use xor to produce +0.0 in a fast and compact way, but avoid to
   // do so if the constant is -0.0.
   if (BitCast<uint64_t, double>(v) == 0) {
@@ skipping 12 matching lines @@
       __ push_imm32(lower);
       __ movdbl(res, Operand(esp, 0));
       __ add(Operand(esp), Immediate(2 * kPointerSize));
     }
   }
 }
 
 
 void LCodeGen::DoConstantT(LConstantT* instr) {
   ASSERT(instr->result()->IsRegister());
-  __ mov(ToRegister(instr->result()), Immediate(instr->value()));
+  __ Set(ToRegister(instr->result()), Immediate(instr->value()));
 }
 
 
 void LCodeGen::DoArrayLength(LArrayLength* instr) {
   Register result = ToRegister(instr->result());
 
   if (instr->hydrogen()->value()->IsLoadElements()) {
     // We load the length directly from the elements array.
     Register elements = ToRegister(instr->input());
     __ mov(result, FieldOperand(elements, FixedArray::kLengthOffset));
@@ skipping 2280 matching lines @@
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal