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OpcodeDispatcher: use ArithRef for rotates

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Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
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Alyssa Rosenzweig committed 2025-06-02 14:15:51 -04:00
1 parent 8093e8f5f1
commit 820d5c1447
1 file changed
+9 -10
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FEXCore/Source/Interface/Core/OpcodeDispatcher.cpp
+9 -10
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@@ -1568,15 +1568,14 @@ void OpDispatchBuilder::RotateOp(OpcodeArgs, bool Left, bool IsImmediate, bool I
// things tighter for 8-bit later in the function.
uint64_t Mask = Size == 8 ? 7 : (Size == 64 ? 0x3F : 0x1F);
Ref Src, UnmaskedSrc;
ArithRef UnmaskedSrc;
if (Is1Bit || IsImmediate) {
UnmaskedConst = LoadConstantShift(Op, Is1Bit);
UnmaskedSrc = _Constant(UnmaskedConst);
Src = _Constant(UnmaskedConst & Mask);
UnmaskedSrc = ARef(UnmaskedConst);
} else {
UnmaskedSrc = LoadSource(GPRClass, Op, Op->Src[1], Op->Flags, {.AllowUpperGarbage = true});
Src = _And(OpSize::i64Bit, UnmaskedSrc, _InlineConstant(Mask));
UnmaskedSrc = ARef(LoadSource(GPRClass, Op, Op->Src[1], Op->Flags, {.AllowUpperGarbage = true}));
}
auto Src = UnmaskedSrc.And(Mask);
// We fill the upper bits so we allow garbage on load.
auto Dest = LoadSource(GPRClass, Op, Op->Dest, Op->Flags, {.AllowUpperGarbage = true});
@@ -1588,18 +1587,18 @@ void OpDispatchBuilder::RotateOp(OpcodeArgs, bool Left, bool IsImmediate, bool I
}
// To rotate 64-bits left, right-rotate by (64 - Shift) = -Shift mod 64.
auto Res = _Ror(OpSize, Dest, Left ? _Neg(OpSize, Src) : Src);
auto Res = _Ror(OpSize, Dest, (Left ? Src.Neg() : Src).Ref());
StoreResult(GPRClass, Op, Res, OpSize::iInvalid);
if (Is1Bit || IsImmediate) {
if (UnmaskedConst) {
if (UnmaskedSrc.C) {
// Extract the last bit shifted in to CF
SetCFDirect(Res, Left ? 0 : Size - 1, true);
// For ROR, OF is the XOR of the new CF bit and the most significant bit of the result.
// For ROL, OF is the LSB and MSB XOR'd together.
// OF is architecturally only defined for 1-bit rotate.
if (UnmaskedConst == 1) {
if (UnmaskedSrc.C == 1) {
auto NewOF = _XorShift(OpSize, Res, Res, ShiftType::LSR, Left ? Size - 1 : 1);
SetRFLAG<FEXCore::X86State::RFLAG_OF_RAW_LOC>(NewOF, Left ? 0 : Size - 2, true);
}
@@ -1610,10 +1609,10 @@ void OpDispatchBuilder::RotateOp(OpcodeArgs, bool Left, bool IsImmediate, bool I
// We deferred the masking for 8-bit to the flag section, do it here.
if (Size == 8) {
Src = _And(OpSize::i64Bit, UnmaskedSrc, _InlineConstant(0x1F));
Src = UnmaskedSrc.And(0x1F);
}
_RotateFlags(OpSizeFromSrc(Op), Res, Src, Left);
_RotateFlags(OpSizeFromSrc(Op), Res, Src.Ref(), Left);
}
}