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emit_x64_floating_point: Fixup special NaN case in FMA FPMulAdd implementation

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This commit is contained in:
MerryMage 2018-07-23 21:10:27 +01:00
parent 070637e0f6
commit 66bb05fc0a
2 changed files with 42 additions and 14 deletions
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36
src/backend_x64/emit_x64_floating_point.cpp
View file

@ -147,7 +147,8 @@ static void PreProcessNaNs32(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbya
code.SwitchToNearCode();
}
static void PreProcessNaNs32(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbyak::Xmm c, Xbyak::Label& end) {
template<typename NaNHandler>
static void PreProcessNaNs32(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbyak::Xmm c, Xbyak::Label& end, NaNHandler nan_handler) {
Xbyak::Label nan;
code.ucomiss(a, b);
@ -165,9 +166,7 @@ static void PreProcessNaNs32(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbya
code.movd(code.ABI_PARAM1.cvt32(), a);
code.movd(code.ABI_PARAM2.cvt32(), b);
code.movd(code.ABI_PARAM3.cvt32(), c);
code.CallFunction(static_cast<u32(*)(u32, u32, u32)>([](u32 a, u32 b, u32 c) -> u32 {
return *FP::ProcessNaNs(a, b, c);
}));
code.CallFunction(static_cast<u32(*)(u32, u32, u32)>(nan_handler));
code.movd(a, code.ABI_RETURN.cvt32());
ABI_PopCallerSaveRegistersAndAdjustStackExcept(code, HostLocXmmIdx(a.getIdx()));
code.add(rsp, 8);
@ -214,7 +213,8 @@ static void PreProcessNaNs64(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbya
code.SwitchToNearCode();
}
static void PreProcessNaNs64(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbyak::Xmm c, Xbyak::Label& end) {
template<typename NaNHandler>
static void PreProcessNaNs64(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbyak::Xmm c, Xbyak::Label& end, NaNHandler nan_handler) {
Xbyak::Label nan;
code.ucomisd(a, b);
@ -229,9 +229,7 @@ static void PreProcessNaNs64(BlockOfCode& code, Xbyak::Xmm a, Xbyak::Xmm b, Xbya
code.movq(code.ABI_PARAM1, a);
code.movq(code.ABI_PARAM2, b);
code.movq(code.ABI_PARAM3, c);
code.CallFunction(static_cast<u64(*)(u64, u64, u64)>([](u64 a, u64 b, u64 c) -> u64 {
return *FP::ProcessNaNs(a, b, c);
}));
code.CallFunction(static_cast<u64(*)(u64, u64, u64)>(nan_handler));
code.movq(a, code.ABI_RETURN);
ABI_PopCallerSaveRegistersAndAdjustStackExcept(code, HostLocXmmIdx(a.getIdx()));
code.add(rsp, 8);
@ -437,8 +435,8 @@ static void FPTwoOp64(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Funct
ctx.reg_alloc.DefineValue(inst, result);
}
template <typename Function>
static void FPFourOp32(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Function fn) {
template <typename Function, typename NaNHandler>
static void FPFourOp32(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Function fn, NaNHandler nan_handler) {
auto args = ctx.reg_alloc.GetArgumentInfo(inst);
Xbyak::Label end;
@ -454,7 +452,7 @@ static void FPFourOp32(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Func
DenormalsAreZero32(code, operand3, gpr_scratch);
}
if (ctx.AccurateNaN() && !ctx.FPSCR_DN()) {
PreProcessNaNs32(code, result, operand2, operand3, end);
PreProcessNaNs32(code, result, operand2, operand3, end, nan_handler);
}
fn(result, operand2, operand3);
if (ctx.FPSCR_FTZ()) {
@ -470,8 +468,8 @@ static void FPFourOp32(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Func
ctx.reg_alloc.DefineValue(inst, result);
}
template <typename Function>
static void FPFourOp64(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Function fn) {
template <typename Function, typename NaNHandler>
static void FPFourOp64(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Function fn, NaNHandler nan_handler) {
auto args = ctx.reg_alloc.GetArgumentInfo(inst);
Xbyak::Label end;
@ -487,7 +485,7 @@ static void FPFourOp64(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst, Func
DenormalsAreZero64(code, operand3, gpr_scratch);
}
if (ctx.AccurateNaN() && !ctx.FPSCR_DN()) {
PreProcessNaNs64(code, result, operand2, operand3, end);
PreProcessNaNs64(code, result, operand2, operand3, end, nan_handler);
}
fn(result, operand2, operand3);
if (ctx.FPSCR_FTZ()) {
@ -787,6 +785,11 @@ void EmitX64::EmitFPMulAdd32(EmitContext& ctx, IR::Inst* inst) {
if (code.DoesCpuSupport(Xbyak::util::Cpu::tFMA)) {
FPFourOp32(code, ctx, inst, [&](Xbyak::Xmm result, Xbyak::Xmm operand2, Xbyak::Xmm operand3) {
code.vfmadd231ss(result, operand2, operand3);
}, [](u32 a, u32 b, u32 c) -> u32 {
if (FP::IsQNaN(a) && ((FP::IsInf(b) && FP::IsZero(c)) || (FP::IsZero(b) && FP::IsInf(c)))) {
return f32_nan;
}
return *FP::ProcessNaNs(a, b, c);
});
return;
}
@ -798,6 +801,11 @@ void EmitX64::EmitFPMulAdd64(EmitContext& ctx, IR::Inst* inst) {
if (code.DoesCpuSupport(Xbyak::util::Cpu::tFMA)) {
FPFourOp64(code, ctx, inst, [&](Xbyak::Xmm result, Xbyak::Xmm operand2, Xbyak::Xmm operand3) {
code.vfmadd231sd(result, operand2, operand3);
}, [](u64 a, u64 b, u64 c) -> u64 {
if (FP::IsQNaN(a) && ((FP::IsInf(b) && FP::IsZero(c)) || (FP::IsZero(b) && FP::IsInf(c)))) {
return f64_nan;
}
return *FP::ProcessNaNs(a, b, c);
});
return;
}

20
src/common/fp/util.h
View file

@ -11,6 +11,16 @@
namespace Dynarmic::FP {
/// Is 32-bit floating point value a zero?
constexpr bool IsZero(u32 value) {
return (value & 0x7fffffff) == 0;
}
/// Is 32-bit floating point value an infinity?
constexpr bool IsInf(u32 value) {
return (value & 0x7fffffff) == 0x7f800000;
}
/// Is 32-bit floating point value a QNaN?
constexpr bool IsQNaN(u32 value) {
return (value & 0x7fc00000) == 0x7fc00000;
@ -60,6 +70,16 @@ inline boost::optional<u32> ProcessNaNs(u32 a, u32 b, u32 c) {
return boost::none;
}
/// Is 64-bit floating point value a zero?
constexpr bool IsZero(u64 value) {
return (value & 0x7FFF'FFFF'FFFF'FFFF) == 0;
}
/// Is 64-bit floating point value an infinity?
constexpr bool IsInf(u64 value) {
return (value & 0x7FFF'FFFF'FFFF'FFFF) == 0x7FF0'0000'0000'000;
}
/// Is 64-bit floating point value a QNaN?
constexpr bool IsQNaN(u64 value) {
return (value & 0x7FF8'0000'0000'0000) == 0x7FF8'0000'0000'0000;