Fixing fix for MathPowHalf on ARM.

Review URL: http://codereview.chromium.org/8817012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10167 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.cc

@@ -1153,6 +1153,11 @@ LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
     LOperand* input = UseFixedDouble(instr->value(), d2);
     LUnaryMathOperation* result = new LUnaryMathOperation(input, NULL);
     return MarkAsCall(DefineFixedDouble(result, d2), instr);
+  } if (op == kMathPowHalf) {
+    LOperand* input = UseFixedDouble(instr->value(), d2);
+    LOperand* temp = FixedTemp(d3);
+    LUnaryMathOperation* result = new LUnaryMathOperation(input, temp);
+    return DefineFixedDouble(result, d2);
   } else {
     LOperand* input = UseRegisterAtStart(instr->value());
     LOperand* temp = (op == kMathFloor) ? TempRegister() : NULL;
@@ -1166,8 +1171,6 @@ LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
         return DefineAsRegister(result);
       case kMathRound:
         return AssignEnvironment(DefineAsRegister(result));
-      case kMathPowHalf:
-        return DefineAsRegister(result);
       default:
         UNREACHABLE();
         return NULL;

src/arm/lithium-codegen-arm.cc

@@ -3097,13 +3097,15 @@ void LCodeGen::DoMathSqrt(LUnaryMathOperation* instr) {
 void LCodeGen::DoMathPowHalf(LUnaryMathOperation* instr) {
   DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
   DoubleRegister result = ToDoubleRegister(instr->result());
+  DoubleRegister temp = ToDoubleRegister(instr->TempAt(0));
 
   // Note that according to ECMA-262 15.8.2.13:
   // Math.pow(-Infinity, 0.5) == Infinity
   // Math.sqrt(-Infinity) == NaN
   Label done;
-  __ VFPCompareAndSetFlags(input, -V8_INFINITY);
-  __ vneg(result, input, eq);
+  __ vmov(temp, -V8_INFINITY);
+  __ VFPCompareAndSetFlags(input, temp);
+  __ vneg(result, temp, eq);
   __ b(&done, eq);
 
   // Add +0 to convert -0 to +0.

test/mjsunit/math-pow.js

@@ -135,7 +135,7 @@ function test() {
   assertEquals(+Infinity, Math.pow(-0, -0.6));
   assertEquals(-Infinity, Math.pow(-0, -1));
   assertEquals(-Infinity, Math.pow(-0, -10000000001));
-  
+
   assertEquals(4, Math.pow(16, 0.5));
   assertEquals(NaN, Math.pow(-16, 0.5));
   assertEquals(0.25, Math.pow(16, -0.5));