ARM: Optimize NumberTagU

src/arm/lithium-codegen-arm.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 4750 matching lines @@
     virtual void Generate() V8_OVERRIDE {
       codegen()->DoDeferredNumberTagI(instr_,
                                       instr_->value(),
                                       UNSIGNED_INT32);
     }
     virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
    private:
     LNumberTagU* instr_;
   };
 
-  LOperand* input = instr->value();
-  ASSERT(input->IsRegister() && input->Equals(instr->result()));
-  Register reg = ToRegister(input);
+  Register input = ToRegister(instr->value());
+  Register result = ToRegister(instr->result());
 
   DeferredNumberTagU* deferred = new(zone()) DeferredNumberTagU(this, instr);
-  __ cmp(reg, Operand(Smi::kMaxValue));
+  __ cmp(input, Operand(Smi::kMaxValue));
   __ b(hi, deferred->entry());
-  __ SmiTag(reg, reg);
+  __ SmiTag(result, input);
   __ bind(deferred->exit());
 }
 
 
 void LCodeGen::DoDeferredNumberTagI(LInstruction* instr,
                                     LOperand* value,
                                     IntegerSignedness signedness) {
   Label slow;
   Register src = ToRegister(value);
   Register dst = ToRegister(instr->result());
@@ skipping 1093 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal