thirdparty/ppsspp
2
0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Shave one instruction off slti and slt on ARM.

Browse source
This commit is contained in:
Henrik Rydgard 2013-11-30 15:53:21 +01:00
parent 8956fb2932
commit 04742e00fc
1 changed files with 13 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

14
Core/MIPS/ARM/ArmCompALU.cpp
View file

@ -106,12 +106,18 @@ namespace MIPSComp
break;
}
gpr.MapDirtyIn(rt, rs);
#if 0
CMPI2R(gpr.R(rs), simm, R0);
SetCC(CC_LT);
MOVI2R(gpr.R(rt), 1);
SetCC(CC_GE);
MOVI2R(gpr.R(rt), 0);
SetCC(CC_AL);
#else
// Simply subtract, then use a logical shift to grab the sign bit.
ADDI2R(R0, gpr.R(rs), -simm, R1);
LSR(gpr.R(rt), R0, 31);
#endif
}
break;
@ -128,6 +134,9 @@ namespace MIPSComp
SetCC(CC_HS);
MOVI2R(gpr.R(rt), 0);
SetCC(CC_AL);
// For unsigned, to do the same trick as with signed we need to extract the carry and that
// is probably more expensive than this.
}
break;
@ -364,7 +373,10 @@ namespace MIPSComp
CMN(gpr.R(rs), op2);
} else {
gpr.MapDirtyInIn(rd, rs, rt);
CMP(gpr.R(rs), gpr.R(rt));
SUB(R0, gpr.R(rs), gpr.R(rt));
LSR(gpr.R(rd), R0, 31);
return;
// CMP(gpr.R(rs), gpr.R(rt));
}
SetCC(caseOne);