Merged r19798, r19896 into 3.24 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 88f76658f32d2da6214c372a2a2cc17c1b81c98f..511b6b6615e1fe9e8d8728d159d3e15c41d3122e 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1121,8 +1121,9 @@ 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));
 }