A64: Improve the deoptimization exit code for LMathRound.

src/a64/lithium-codegen-a64.cc

Index: src/a64/lithium-codegen-a64.cc
diff --git a/src/a64/lithium-codegen-a64.cc b/src/a64/lithium-codegen-a64.cc
index 48f8ea6136f34c07a9c62b332cb2a2d41d9398f5..63ef184ece3c61cd1fcdcbd73b49f895db4312e2 100644
--- a/src/a64/lithium-codegen-a64.cc
+++ b/src/a64/lithium-codegen-a64.cc
@@ -4025,7 +4025,6 @@ void LCodeGen::DoMathRound(LMathRound* instr) {
   DoubleRegister temp1 = ToDoubleRegister(instr->temp1());
   Register result = ToRegister(instr->result());
   Label try_rounding;
-  Label deopt;
   Label done;
 
   // Math.round() rounds to the nearest integer, with ties going towards
@@ -4047,8 +4046,7 @@ void LCodeGen::DoMathRound(LMathRound* instr) {
 
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     __ Fmov(result, input);
-    __ Cmp(result, 0);
-    DeoptimizeIf(mi, instr->environment());  // [-0.5, -0.0].
+    DeoptimizeIfNegative(result, instr->environment());  // [-0.5, -0.0].
   }
   __ Fcmp(input, dot_five);
   __ Mov(result, 1);  // +0.5.
@@ -4057,9 +4055,6 @@ void LCodeGen::DoMathRound(LMathRound* instr) {
   __ Csel(result, result, xzr, eq);
   __ B(&done);
 
-  __ Bind(&deopt);
-  Deoptimize(instr->environment());
-
   __ Bind(&try_rounding);
   // Since we're providing a 32-bit result, we can implement ties-to-infinity by
   // adding 0.5 to the input, then taking the floor of the result. This does not
@@ -4074,7 +4069,7 @@ void LCodeGen::DoMathRound(LMathRound* instr) {
   //  * the result is not representable using a 32-bit integer.
   __ Fcmp(input, 0.0);
   __ Ccmp(result, Operand(result.W(), SXTW), NoFlag, vc);
-  __ B(ne, &deopt);
+  DeoptimizeIf(ne, instr->environment());
 
   __ Bind(&done);
 }