correct the subtraction instructions and try something more sensible for overflow detection

This commit is contained in:
Peter Tissen 2014-03-19 18:13:52 +01:00
parent 27bb41d652
commit acf955635f

View File

@ -2612,10 +2612,10 @@ private:
}
void SUBFE(u32 rd, u32 ra, u32 rb, u32 oe, bool rc)
{
const s64 RA = CPU.GPR[ra];
const s64 RB = CPU.GPR[rb];
const u64 RA = CPU.GPR[ra];
const u64 RB = CPU.GPR[rb];
CPU.GPR[rd] = ~RA + RB + CPU.XER.CA;
CPU.XER.CA = ((u64)~RA + CPU.XER.CA > ~(u64)RB) | ((RA == 0) & CPU.XER.CA);
CPU.XER.CA = (~RA + CPU.XER.CA > ~RB) | ((RA == 0) & CPU.XER.CA);
if(rc) CPU.UpdateCR0<s64>(CPU.GPR[rd]);
if(oe) UNK("subfeo");
}
@ -2736,9 +2736,9 @@ private:
}
void SUBFZE(u32 rd, u32 ra, u32 oe, bool rc)
{
const u64 nRA = ~CPU.GPR[ra];
CPU.GPR[rd] = nRA + CPU.XER.CA;
CPU.XER.CA = CPU.IsCarry(nRA, CPU.XER.CA);
const u64 RA = CPU.GPR[ra];
CPU.GPR[rd] = ~RA + CPU.XER.CA;
CPU.XER.CA = (0x8000000000000000 & RA) && (0x8000000000000000 & CPU.GPR[rd]);//RA <= 0ull;
if (oe) ConLog.Warning("subfzeo");
if (rc) CPU.UpdateCR0<s64>(CPU.GPR[rd]);
}
@ -2769,9 +2769,9 @@ private:
}
void SUBFME(u32 rd, u32 ra, u32 oe, bool rc)
{
const u64 nRA = ~CPU.GPR[ra];
CPU.GPR[rd] = nRA + CPU.XER.CA + 0xFFFFFFFF;
CPU.XER.CA = CPU.IsCarry(nRA, CPU.XER.CA) || CPU.IsCarry(nRA, CPU.XER.CA + 0xFFFFFFFF);
const u64 RA = CPU.GPR[ra];
CPU.GPR[rd] = ~RA + CPU.XER.CA + 0xFFFFFFFFFFFFFFFF;
CPU.XER.CA = !(0x8000000000000000 & RA) && !(0x8000000000000000 & CPU.GPR[rd]);
if (oe) ConLog.Warning("subfmeo");
if (rc) CPU.UpdateCR0<s64>(CPU.GPR[rd]);
}