ARM: Optimize NumberTagU

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 164ee553daa0fd409d8e786882c1bb576a254fb2..f77a065c38457c67bc0fe357e1744cd3c7bf88a9 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4768,14 +4768,13 @@ void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
     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());
 }