ShuriZma
/
pcsx2
mirror of https://github.com/PCSX2/pcsx2.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Just adding some comments to MMI fix.

This commit is contained in:
refractionpcsx2 2018-07-31 18:48:51 +01:00
parent 1e0b0605a6
commit 8b0114596b
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
pcsx2/MMI.cpp
View File

@ -1052,13 +1052,14 @@ static __fi void _PMADDW(int dd, int ss)
s64 temp = ((s64)cpuRegs.GPR.r[_Rs_].SL[ss] * (s64)cpuRegs.GPR.r[_Rt_].SL[ss]);
s64 temp2 = temp + ((s64)cpuRegs.HI.SL[ss] << 32);
//Playstation 2 division voodoo, for some reason only the lower half is affected
if (ss == 0)
{
if (((cpuRegs.GPR.r[_Rt_].SL[ss] & 0x7FFFFFFF) == 0 || (cpuRegs.GPR.r[_Rt_].SL[ss] & 0x7FFFFFFF) == 0x7FFFFFFF) &&
cpuRegs.GPR.r[_Rs_].SL[ss] != cpuRegs.GPR.r[_Rt_].SL[ss])
temp2 += 0x70000000;
}
//Multiplication error on the PS2 causes this not to be exactly >> 32 (off by 1)
temp2 = (s32)(temp2 / 4294967295);
cpuRegs.LO.SD[dd] = (s32)(temp & 0xffffffff) + cpuRegs.LO.SL[ss];
@ -1099,6 +1100,7 @@ __fi void _PMSUBW(int dd, int ss)
s64 temp = ((s64)cpuRegs.GPR.r[_Rs_].SL[ss] * (s64)cpuRegs.GPR.r[_Rt_].SL[ss]);
s64 temp2 = ((s64)cpuRegs.HI.SL[ss] << 32) - temp;
//Multiplication error on the PS2 causes this not to be exactly >> 32 (off by 1)
temp2 = (s32)(temp2 / 4294967295);
cpuRegs.LO.SD[dd] = cpuRegs.LO.SL[ss] - (s32)(temp & 0xffffffff);