Merged r19798, r19896 into 3.23 branch.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 473e93dde6f42369619e1198ee1d96d2dc4d7888..b1d92f563611397ec1dee4902aa7826883536ef8 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1208,8 +1208,9 @@ LInstruction* LChunkBuilder::DoMathFloor(HUnaryMathOperation* instr) {
 
 
 LInstruction* LChunkBuilder::DoMathRound(HUnaryMathOperation* instr) {
-  LOperand* input = UseRegisterAtStart(instr->value());
-  LMathRound* result = new(zone()) LMathRound(input);
+  LOperand* input = UseRegister(instr->value());
+  LOperand* temp = FixedTemp(xmm4);
+  LMathRound* result = new(zone()) LMathRound(input, temp);
   return AssignEnvironment(DefineAsRegister(result));
 }