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OpcodeDispatcher: rm deferred variable shift flag calcs
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Signed-off-by: Alyssa Rosenzweig <[email protected]>
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@alyssarosenzweig
alyssarosenzweig committed Apr 5, 2024
1 parent b1d1a3a commit 75216fa
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Showing 2 changed files with 1 addition and 151 deletions.
64 changes: 1 addition & 63 deletions FEXCore/Source/Interface/Core/OpcodeDispatcher.h
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Original file line number Diff line number Diff line change
Expand Up @@ -81,12 +81,9 @@ friend class FEXCore::IR::PassManager;
TYPE_MUL,
TYPE_UMUL,
TYPE_LOGICAL,
TYPE_LSHL,
TYPE_LSHLI,
TYPE_LSHR,
TYPE_LSHRI,
TYPE_LSHRDI,
TYPE_ASHR,
TYPE_ASHRI,
TYPE_BEXTR,
TYPE_BLSI,
Expand Down Expand Up @@ -1675,7 +1672,7 @@ friend class FEXCore::IR::PassManager;
OrderedNode *Src1;
} OneSource;

// Logical, LSHL, LSHR, ASHR
// Logical
struct {
OrderedNode *Src1;
OrderedNode *Src2;
Expand Down Expand Up @@ -1761,13 +1758,6 @@ friend class FEXCore::IR::PassManager;
PossiblySetNZCVBits |= OldSetNZCVBits;
}

template <typename F>
void CalculateFlags_ShiftVariable(OrderedNode *Shift, F&& CalculateFlags) {
// We are the ones calculating the deferred flags. Don't recurse!
InvalidateDeferredFlags();
Calculate_ShiftVariable(Shift, CalculateFlags);
}

/**
* @name These functions are used by the deferred flag handling while it is calculating and storing flags in to RFLAGs.
* @{ */
Expand All @@ -1793,7 +1783,6 @@ friend class FEXCore::IR::PassManager;
void CalculateFlags_ShiftRightImmediate(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, uint64_t Shift);
void CalculateFlags_ShiftRightDoubleImmediate(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, uint64_t Shift);
void CalculateFlags_ShiftRightImmediateCommon(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, uint64_t Shift);
void CalculateFlags_SignShiftRight(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2);
void CalculateFlags_SignShiftRightImmediate(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, uint64_t Shift);
void CalculateFlags_BEXTR(OrderedNode *Src);
void CalculateFlags_BLSI(uint8_t SrcSize, OrderedNode *Src);
Expand Down Expand Up @@ -1863,57 +1852,6 @@ friend class FEXCore::IR::PassManager;
};
}

void GenerateFlags_ShiftLeft(FEXCore::X86Tables::DecodedOp Op, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2) {
// Flags need to be used, generate incoming flags first.
CalculateDeferredFlags();

CurrentDeferredFlags = DeferredFlagData {
.Type = FlagsGenerationType::TYPE_LSHL,
.SrcSize = GetSrcSize(Op),
.Res = Res,
.Sources = {
.TwoSource = {
.Src1 = Src1,
.Src2 = Src2,
},
},
};
}

void GenerateFlags_ShiftRight(FEXCore::X86Tables::DecodedOp Op, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2) {
// Flags need to be used, generate incoming flags first.
CalculateDeferredFlags();

CurrentDeferredFlags = DeferredFlagData {
.Type = FlagsGenerationType::TYPE_LSHR,
.SrcSize = GetSrcSize(Op),
.Res = Res,
.Sources = {
.TwoSource = {
.Src1 = Src1,
.Src2 = Src2,
},
},
};
}

void GenerateFlags_SignShiftRight(FEXCore::X86Tables::DecodedOp Op, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2) {
// Flags need to be used, generate incoming flags first.
CalculateDeferredFlags();

CurrentDeferredFlags = DeferredFlagData {
.Type = FlagsGenerationType::TYPE_ASHR,
.SrcSize = GetSrcSize(Op),
.Res = Res,
.Sources = {
.TwoSource = {
.Src1 = Src1,
.Src2 = Src2,
},
},
};
}

void GenerateFlags_ShiftLeftImmediate(FEXCore::X86Tables::DecodedOp Op, OrderedNode *Res, OrderedNode *Src1, uint64_t Shift) {
// No flags changed if shift is zero.
if (Shift == 0) return;
Expand Down
88 changes: 0 additions & 88 deletions FEXCore/Source/Interface/Core/OpcodeDispatcher/Flags.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -303,27 +303,13 @@ void OpDispatchBuilder::CalculateDeferredFlags(uint32_t FlagsToCalculateMask) {
CurrentDeferredFlags.Sources.TwoSource.Src1,
CurrentDeferredFlags.Sources.TwoSource.Src2);
break;
case FlagsGenerationType::TYPE_LSHL:
CalculateFlags_ShiftLeft(
CurrentDeferredFlags.SrcSize,
CurrentDeferredFlags.Res,
CurrentDeferredFlags.Sources.TwoSource.Src1,
CurrentDeferredFlags.Sources.TwoSource.Src2);
break;
case FlagsGenerationType::TYPE_LSHLI:
CalculateFlags_ShiftLeftImmediate(
CurrentDeferredFlags.SrcSize,
CurrentDeferredFlags.Res,
CurrentDeferredFlags.Sources.OneSrcImmediate.Src1,
CurrentDeferredFlags.Sources.OneSrcImmediate.Imm);
break;
case FlagsGenerationType::TYPE_LSHR:
CalculateFlags_ShiftRight(
CurrentDeferredFlags.SrcSize,
CurrentDeferredFlags.Res,
CurrentDeferredFlags.Sources.TwoSource.Src1,
CurrentDeferredFlags.Sources.TwoSource.Src2);
break;
case FlagsGenerationType::TYPE_LSHRI:
CalculateFlags_ShiftRightImmediate(
CurrentDeferredFlags.SrcSize,
Expand All @@ -338,13 +324,6 @@ void OpDispatchBuilder::CalculateDeferredFlags(uint32_t FlagsToCalculateMask) {
CurrentDeferredFlags.Sources.OneSrcImmediate.Src1,
CurrentDeferredFlags.Sources.OneSrcImmediate.Imm);
break;
case FlagsGenerationType::TYPE_ASHR:
CalculateFlags_SignShiftRight(
CurrentDeferredFlags.SrcSize,
CurrentDeferredFlags.Res,
CurrentDeferredFlags.Sources.TwoSource.Src1,
CurrentDeferredFlags.Sources.TwoSource.Src2);
break;
case FlagsGenerationType::TYPE_ASHRI:
CalculateFlags_SignShiftRightImmediate(
CurrentDeferredFlags.SrcSize,
Expand Down Expand Up @@ -580,73 +559,6 @@ void OpDispatchBuilder::CalculateFlags_Logical(uint8_t SrcSize, OrderedNode *Res
SetNZ_ZeroCV(SrcSize, Res);
}

void OpDispatchBuilder::CalculateFlags_ShiftLeft(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2) {
CalculateFlags_ShiftVariable(Src2, [this, SrcSize, Res, Src1, Src2](){
const auto OpSize = SrcSize == 8 ? OpSize::i64Bit : OpSize::i32Bit;
SetNZ_ZeroCV(SrcSize, Res);

// Extract the last bit shifted in to CF
auto Size = _Constant(SrcSize * 8);
auto ShiftAmt = SrcSize >= 4 ? _Neg(OpSize, Src2) : _Sub(OpSize, Size, Src2);
auto LastBit = _Lshr(OpSize, Src1, ShiftAmt);
SetRFLAG<FEXCore::X86State::RFLAG_CF_RAW_LOC>(LastBit, 0, true);

CalculatePF(Res);

// AF
// Undefined
_InvalidateFlags(1 << X86State::RFLAG_AF_RAW_LOC);

// In the case of left shift. OF is only set from the result of <Top Source Bit> XOR <Top Result Bit>
// When Shift > 1 then OF is undefined
auto OFXor = _Xor(OpSize, Src1, Res);
SetRFLAG<FEXCore::X86State::RFLAG_OF_RAW_LOC>(OFXor, SrcSize * 8 - 1, true);
});
}

void OpDispatchBuilder::CalculateFlags_ShiftRight(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2) {
CalculateFlags_ShiftVariable(Src2, [this, SrcSize, Res, Src1, Src2](){
const auto OpSize = SrcSize == 8 ? OpSize::i64Bit : OpSize::i32Bit;
SetNZ_ZeroCV(SrcSize, Res);

// Extract the last bit shifted in to CF
auto ShiftAmt = _Sub(OpSize::i64Bit, Src2, _Constant(1));
const auto CFSize = IR::SizeToOpSize(std::max<uint8_t>(4u, SrcSize));
auto LastBit = _Lshr(CFSize, Src1, ShiftAmt);
SetRFLAG<FEXCore::X86State::RFLAG_CF_RAW_LOC>(LastBit, 0, true);

CalculatePF(Res);

// AF
// Undefined
_InvalidateFlags(1 << X86State::RFLAG_AF_RAW_LOC);

// Only defined when Shift is 1 else undefined
// OF flag is set if a sign change occurred
auto val = _Xor(OpSize, Src1, Res);
SetRFLAG<FEXCore::X86State::RFLAG_OF_RAW_LOC>(val, SrcSize * 8 - 1, true);
});
}

void OpDispatchBuilder::CalculateFlags_SignShiftRight(uint8_t SrcSize, OrderedNode *Res, OrderedNode *Src1, OrderedNode *Src2) {
CalculateFlags_ShiftVariable(Src2, [this, SrcSize, Res, Src1, Src2](){
// SF/ZF/OF
SetNZ_ZeroCV(SrcSize, Res);

// Extract the last bit shifted in to CF
const auto CFSize = IR::SizeToOpSize(std::max<uint32_t>(4u, GetOpSize(Src1)));
auto ShiftAmt = _Sub(OpSize::i64Bit, Src2, _Constant(1));
auto LastBit = _Lshr(CFSize, Src1, ShiftAmt);
SetRFLAG<FEXCore::X86State::RFLAG_CF_RAW_LOC>(LastBit, 0, true);

CalculatePF(Res);

// AF
// Undefined
_InvalidateFlags(1 << X86State::RFLAG_AF_RAW_LOC);
});
}

void OpDispatchBuilder::CalculateFlags_ShiftLeftImmediate(uint8_t SrcSize, OrderedNode *UnmaskedRes, OrderedNode *Src1, uint64_t Shift) {
// No flags changed if shift is zero
if (Shift == 0) return;
Expand Down

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