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DSPLLE: NEG can set the carry and overflow flags

This commit is contained in:
Pokechu22 2021-08-18 16:28:08 -07:00
parent 3ee605d699
commit 779cd479bc
2 changed files with 32 additions and 14 deletions
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15
Source/Core/Core/DSP/Interpreter/DSPIntArithmetic.cpp
View File

@ -704,18 +704,23 @@ void Interpreter::dec(const UDSPInstruction opc)
// 0111 110d xxxx xxxx
// Negate accumulator $acD.
//
// flags out: --xx xx00
// flags out: x-xx xxxx
//
// The carry flag is set only if $acD was zero.
// The overflow flag is set only if $acD was 0x8000000000 (the minimum value),
// as -INT_MIN is INT_MIN in two's complement. In both of these cases,
// the value of $acD after the operation is the same as it was before.
void Interpreter::neg(const UDSPInstruction opc)
{
const u8 dreg = (opc >> 8) & 0x1;
s64 acc = GetLongAcc(dreg);
acc = 0 - acc;
const s64 acc = GetLongAcc(dreg);
const s64 res = 0 - acc;
ZeroWriteBackLog();
SetLongAcc(dreg, acc);
UpdateSR64(GetLongAcc(dreg));
SetLongAcc(dreg, res);
UpdateSR64Sub(0, acc, GetLongAcc(dreg));
}
// ABS $acD

31
Source/Core/Core/DSP/Jit/x64/DSPJitArithmetic.cpp
View File

@ -1002,20 +1002,33 @@ void DSPEmitter::dec(const UDSPInstruction opc)
// 0111 110d xxxx xxxx
// Negate accumulator $acD.
//
// flags out: --xx xx00
// flags out: x-xx xxxx
//
// The carry flag is set only if $acD was zero.
// The overflow flag is set only if $acD was 0x8000000000 (the minimum value),
// as -INT_MIN is INT_MIN in two's complement. In both of these cases,
// the value of $acD after the operation is the same as it was before.
void DSPEmitter::neg(const UDSPInstruction opc)
{
u8 dreg = (opc >> 8) & 0x1;
// s64 acc = dsp_get_long_acc(dreg);
get_long_acc(dreg);
// acc = 0 - acc;
NEG(64, R(RAX));
// dsp_set_long_acc(dreg, acc);
set_long_acc(dreg);
// Update_SR_Register64(dsp_get_long_acc(dreg));
// const s64 acc = GetLongAcc(dreg);
X64Reg acc = RAX;
get_long_acc(dreg, acc);
// const s64 res = 0 - acc;
X64Reg res = RCX;
MOV(64, R(res), R(acc));
NEG(64, R(res));
// SetLongAcc(dreg, res);
set_long_acc(dreg, res);
if (FlagsNeeded())
{
Update_SR_Register64();
// UpdateSR64Sub(0, acc, GetLongAcc(dreg));
get_long_acc(dreg, res);
X64Reg imm_reg = RDX;
XOR(64, R(imm_reg), R(imm_reg));
X64Reg tmp1 = m_gpr.GetFreeXReg();
UpdateSR64Sub(imm_reg, acc, res, tmp1);
m_gpr.PutXReg(tmp1);
}
}