void LCodeGen::DoMathPowHalf(LUnaryMathOperation* instr) {
DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
DoubleRegister result = ToDoubleRegister(instr->result());
- DoubleRegister double_scratch = double_scratch0();
+ DoubleRegister temp = ToDoubleRegister(instr->TempAt(0));
+
+ ASSERT(!input.is(result));
+
+ // Note that according to ECMA-262 15.8.2.13:
+ // Math.pow(-Infinity, 0.5) == Infinity
+ // Math.sqrt(-Infinity) == NaN
+ Label done;
+ __ Move(temp, -V8_INFINITY);
+ __ BranchF(USE_DELAY_SLOT, &done, NULL, eq, temp, input);
+ // Set up Infinity in the delay slot.
+ // result is overwritten if the branch is not taken.
+ __ neg_d(result, temp);
// Add +0 to convert -0 to +0.
- __ mtc1(zero_reg, double_scratch.low());
- __ mtc1(zero_reg, double_scratch.high());
- __ add_d(result, input, double_scratch);
+ __ add_d(result, input, kDoubleRegZero);
__ sqrt_d(result, result);
+ __ bind(&done);
}
LOperand* input = UseFixedDouble(instr->value(), f4);
LUnaryMathOperation* result = new LUnaryMathOperation(input, NULL);
return MarkAsCall(DefineFixedDouble(result, f4), instr);
+ } else if (op == kMathPowHalf) {
+ // Input cannot be the same as the result.
+ // See lithium-codegen-mips.cc::DoMathPowHalf.
+ LOperand* input = UseFixedDouble(instr->value(), f8);
+ LOperand* temp = FixedTemp(f6);
+ LUnaryMathOperation* result = new LUnaryMathOperation(input, temp);
+ return DefineFixedDouble(result, f4);
} else {
LOperand* input = UseRegisterAtStart(instr->value());
LOperand* temp = (op == kMathFloor) ? TempRegister() : NULL;
return DefineAsRegister(result);
case kMathRound:
return AssignEnvironment(DefineAsRegister(result));
- case kMathPowHalf:
- return DefineAsRegister(result);
default:
UNREACHABLE();
return NULL;