ShuriZma
/
dolphin
mirror of https://github.com/dolphin-emu/dolphin.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Jit64: Don't use fregsIn in HandleNaNs 

fregsIn will include FD for double-precision instructions, since for
dependency tracking purposes the instruction does read the upper
half of FD. This is not what we want in HandleNaNs.

The consequence of this bug is that if an instruction was supposed to
output a NaN and FD happens to contain a NaN and FD happens to be the
same register as an unused register in the instruction encoding, the
NaN in FD could get used as the output instead of the correct NaN.
This isn't known to affect any games, which isn't especially surprising
considering that there's only one game that needs AccurateNaNs anyway.
This commit is contained in:
JosJuice 2022-10-08 18:19:37 +02:00
parent cd1f89a02b
commit 2a5f4a2390
3 changed files with 16 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Source/Core/Core/PowerPC/Jit64/Jit.h
View File

@ -126,7 +126,8 @@ public:
void FinalizeSingleResult(Gen::X64Reg output, const Gen::OpArg& input, bool packed = true,
bool duplicate = false);
void FinalizeDoubleResult(Gen::X64Reg output, const Gen::OpArg& input);
void HandleNaNs(UGeckoInstruction inst, Gen::X64Reg xmm, Gen::X64Reg clobber);
void HandleNaNs(UGeckoInstruction inst, Gen::X64Reg xmm, Gen::X64Reg clobber,
std::vector<int> inputs);
void MultiplyImmediate(u32 imm, int a, int d, bool overflow);

25
Source/Core/Core/PowerPC/Jit64/Jit_FloatingPoint.cpp
View File

@ -92,7 +92,7 @@ void Jit64::FinalizeDoubleResult(X64Reg output, const OpArg& input)
SetFPRFIfNeeded(input, false);
}
void Jit64::HandleNaNs(UGeckoInstruction inst, X64Reg xmm, X64Reg clobber)
void Jit64::HandleNaNs(UGeckoInstruction inst, X64Reg xmm, X64Reg clobber, std::vector<int> inputs)
{
// | PowerPC | x86
// ---------------------+----------+---------
@ -107,14 +107,13 @@ void Jit64::HandleNaNs(UGeckoInstruction inst, X64Reg xmm, X64Reg clobber)
ASSERT(xmm != clobber);
std::vector<u32> inputs;
u32 a = inst.FA, b = inst.FB, c = inst.FC;
for (u32 i : {a, b, c})
// Remove duplicates from inputs
for (auto it = inputs.begin(); it != inputs.end();)
{
if (!js.op->fregsIn[i])
continue;
if (std::find(inputs.begin(), inputs.end(), i) == inputs.end())
inputs.push_back(i);
if (std::find(inputs.begin(), it, *it) != it)
it = inputs.erase(it);
else
++it;
}
if (inst.OPCD != 4)
@ -128,7 +127,7 @@ void Jit64::HandleNaNs(UGeckoInstruction inst, X64Reg xmm, X64Reg clobber)
// If any inputs are NaNs, pick the first NaN of them
std::vector<FixupBranch> fixups;
for (u32 x : inputs)
for (int x : inputs)
{
RCOpArg Rx = fpr.Use(x, RCMode::Read);
RegCache::Realize(Rx);
@ -168,7 +167,7 @@ void Jit64::HandleNaNs(UGeckoInstruction inst, X64Reg xmm, X64Reg clobber)
BLENDVPD(xmm, MConst(psGeneratedQNaN));
// If any inputs are NaNs, use those instead
for (u32 x : inputs)
for (int x : inputs)
{
RCOpArg Rx = fpr.Use(x, RCMode::Read);
RegCache::Realize(Rx);
@ -198,7 +197,7 @@ void Jit64::HandleNaNs(UGeckoInstruction inst, X64Reg xmm, X64Reg clobber)
MOVAPD(xmm, tmp);
// If any inputs are NaNs, use those instead
for (u32 x : inputs)
for (int x : inputs)
{
RCOpArg Rx = fpr.Use(x, RCMode::Read);
RegCache::Realize(Rx);
@ -277,7 +276,7 @@ void Jit64::fp_arith(UGeckoInstruction inst)
avx_op(avxOp, sseOp, dest, Rop1, Rop2, packed, reversible);
}
HandleNaNs(inst, dest, XMM0);
HandleNaNs(inst, dest, XMM0, {op1, op2});
if (single)
FinalizeSingleResult(Rd, R(dest), packed, true);
else
@ -500,7 +499,7 @@ void Jit64::fmaddXX(UGeckoInstruction inst)
result_xmm = Rd;
}
HandleNaNs(inst, result_xmm, XMM0);
HandleNaNs(inst, result_xmm, XMM0, {a, b, c});
if (single)
FinalizeSingleResult(Rd, R(result_xmm), packed, true);

4
Source/Core/Core/PowerPC/Jit64/Jit_Paired.cpp
View File

@ -77,7 +77,7 @@ void Jit64::ps_sum(UGeckoInstruction inst)
default:
PanicAlertFmt("ps_sum WTF!!!");
}
HandleNaNs(inst, tmp, tmp == XMM1 ? XMM0 : XMM1);
HandleNaNs(inst, tmp, tmp == XMM1 ? XMM0 : XMM1, {a, b, c});
FinalizeSingleResult(Rd, R(tmp));
}
@ -112,7 +112,7 @@ void Jit64::ps_muls(UGeckoInstruction inst)
if (round_input)
Force25BitPrecision(XMM1, R(XMM1), XMM0);
MULPD(XMM1, Ra);
HandleNaNs(inst, XMM1, XMM0);
HandleNaNs(inst, XMM1, XMM0, {a, c});
FinalizeSingleResult(Rd, R(XMM1));
}