void
CodeGeneratorX86::visitOutOfLineTruncateFloat32(OutOfLineTruncateFloat32* ool)
{
LTruncateFToInt32* ins = ool->ins();
FloatRegister input = ToFloatRegister(ins->input());
Register output = ToRegister(ins->output());
Label fail;
if (Assembler::HasSSE3()) {
// Push float32, but subtracts 64 bits so that the value popped by fisttp fits
masm.subl(Imm32(sizeof(uint64_t)), esp);
masm.storeFloat32(input, Operand(esp, 0));
static const uint32_t EXPONENT_MASK = FloatingPoint<float>::kExponentBits;
static const uint32_t EXPONENT_SHIFT = FloatingPoint<float>::kExponentShift;
// Integers are still 64 bits long, so we can still test for an exponent > 63.
static const uint32_t TOO_BIG_EXPONENT = (FloatingPoint<float>::kExponentBias + 63)
<< EXPONENT_SHIFT;
// Check exponent to avoid fp exceptions.
Label failPopFloat;
masm.movl(Operand(esp, 0), output);
masm.and32(Imm32(EXPONENT_MASK), output);
masm.branch32(Assembler::GreaterThanOrEqual, output, Imm32(TOO_BIG_EXPONENT), &failPopFloat);
// Load float, perform 32-bit truncation.
masm.fld32(Operand(esp, 0));
masm.fisttp(Operand(esp, 0));
// Load low word, pop 64bits and jump back.
masm.load32(Address(esp, 0), output);
masm.addl(Imm32(sizeof(uint64_t)), esp);
masm.jump(ool->rejoin());
masm.bind(&failPopFloat);
masm.addl(Imm32(sizeof(uint64_t)), esp);
masm.jump(&fail);
} else {
FloatRegister temp = ToFloatRegister(ins->tempFloat());
// Try to convert float32 representing integers within 2^32 of a signed
// integer, by adding/subtracting 2^32 and then trying to convert to int32.
// This has to be an exact conversion, as otherwise the truncation works
// incorrectly on the modified value.
masm.zeroFloat32(ScratchFloat32Reg);
masm.vucomiss(ScratchFloat32Reg, input);
masm.j(Assembler::Parity, &fail);
{
Label positive;
masm.j(Assembler::Above, &positive);
masm.loadConstantFloat32(4294967296.f, temp);
Label skip;
masm.jmp(&skip);
masm.bind(&positive);
masm.loadConstantFloat32(-4294967296.f, temp);
masm.bind(&skip);
}
masm.addFloat32(input, temp);
masm.vcvttss2si(temp, output);
masm.vcvtsi2ss(output, ScratchFloat32Reg, ScratchFloat32Reg);
masm.vucomiss(ScratchFloat32Reg, temp);
masm.j(Assembler::Parity, &fail);
masm.j(Assembler::Equal, ool->rejoin());
}
masm.bind(&fail);
{
saveVolatile(output);
masm.push(input);
masm.setupUnalignedABICall(output);
masm.vcvtss2sd(input, input, input);
masm.passABIArg(input.asDouble(), MoveOp::DOUBLE);
if (gen->compilingAsmJS())
masm.callWithABI(AsmJSImm_ToInt32);
else
masm.callWithABI(BitwiseCast<void*, int32_t(*)(double)>(JS::ToInt32));
masm.storeCallResult(output);
masm.pop(input);
restoreVolatile(output);
}
masm.jump(ool->rejoin());
}
void
CodeGeneratorX86::visitOutOfLineTruncateFloat32(OutOfLineTruncateFloat32* ool)
{
LTruncateFToInt32* ins = ool->ins();
FloatRegister input = ToFloatRegister(ins->input());
Register output = ToRegister(ins->output());
Label fail;
if (Assembler::HasSSE3()) {
Label failPopFloat;
// Push float32, but subtracts 64 bits so that the value popped by fisttp fits
masm.subl(Imm32(sizeof(uint64_t)), esp);
masm.storeFloat32(input, Operand(esp, 0));
// Check exponent to avoid fp exceptions.
masm.branchDoubleNotInInt64Range(Address(esp, 0), output, &failPopFloat);
// Load float, perform 32-bit truncation.
masm.truncateFloat32ToInt64(Address(esp, 0), Address(esp, 0), output);
// Load low word, pop 64bits and jump back.
masm.load32(Address(esp, 0), output);
masm.addl(Imm32(sizeof(uint64_t)), esp);
masm.jump(ool->rejoin());
masm.bind(&failPopFloat);
masm.addl(Imm32(sizeof(uint64_t)), esp);
masm.jump(&fail);
} else {
FloatRegister temp = ToFloatRegister(ins->tempFloat());
// Try to convert float32 representing integers within 2^32 of a signed
// integer, by adding/subtracting 2^32 and then trying to convert to int32.
// This has to be an exact conversion, as otherwise the truncation works
// incorrectly on the modified value.
masm.zeroFloat32(ScratchFloat32Reg);
masm.vucomiss(ScratchFloat32Reg, input);
masm.j(Assembler::Parity, &fail);
{
Label positive;
masm.j(Assembler::Above, &positive);
masm.loadConstantFloat32(4294967296.f, temp);
Label skip;
masm.jmp(&skip);
masm.bind(&positive);
masm.loadConstantFloat32(-4294967296.f, temp);
masm.bind(&skip);
}
masm.addFloat32(input, temp);
masm.vcvttss2si(temp, output);
masm.vcvtsi2ss(output, ScratchFloat32Reg, ScratchFloat32Reg);
masm.vucomiss(ScratchFloat32Reg, temp);
masm.j(Assembler::Parity, &fail);
masm.j(Assembler::Equal, ool->rejoin());
}
masm.bind(&fail);
{
saveVolatile(output);
masm.Push(input);
if (gen->compilingWasm())
masm.setupWasmABICall();
else
masm.setupUnalignedABICall(output);
masm.vcvtss2sd(input, input, input);
masm.passABIArg(input.asDouble(), MoveOp::DOUBLE);
if (gen->compilingWasm())
masm.callWithABI(ins->mir()->bytecodeOffset(), wasm::SymbolicAddress::ToInt32);
else
masm.callWithABI(BitwiseCast<void*, int32_t(*)(double)>(JS::ToInt32));
masm.storeCallWordResult(output);
masm.Pop(input);
restoreVolatile(output);
}
masm.jump(ool->rejoin());
}
