Jit64: Correctly handle NaNs for ps_mulsX/ps_sumX #11304
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JosJuice
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Source/Core/Core/PowerPC/Jit64/Jit.h
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| @@ -127,7 +129,8 @@ class Jit64 : public JitBase, public QuantizedMemoryRoutines | |||
| bool duplicate = false); | |||
| void FinalizeDoubleResult(Gen::X64Reg output, const Gen::OpArg& input); | |||
| void HandleNaNs(UGeckoInstruction inst, Gen::X64Reg xmm, Gen::X64Reg clobber, | |||
| std::vector<int> inputs); | |||
| const std::optional<Gen::OpArg> Ra, const std::optional<Gen::OpArg> Rb, | |||
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if these aren't passed by reference or pointer, then the const does nothing in the declaration
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Yeah. I iterated on a few different approaches for how to pass the operands, and I think this was a leftover from an iteration where I was using references.
Now that I think about it, the switch away from a vector isn't actually necessary with the current approach... Any opinions on that one?
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I don't really have that strong an opinion either way. It's nice to not need to heap allocate, though
Operations that have two operands and can't generate a default NaN, i.e. addition and subtraction, already have the desired NaN handling on x86. We just need to make sure to not reverse the operands. This fixes ps_sum0/ps_sum1 outputting NaNs in cases where they shouldn't. (HandleNaNs assumes that a NaN in a ps0 input always results in a NaN in the ps0 output, and correspondingly for ps1.)
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HandleNaNs assumes that a NaN in a ps0 input always results in a NaN in the ps0 output, and correspondingly for ps1. This isn't the case for ps_mulsX and ps_sumX.