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X86: Implement an integer media subtract microop.

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This commit is contained in:
Gabe Black 2009-08-17 20:15:15 -07:00
parent c40698e315
commit a4437f8f14
1 changed files with 39 additions and 0 deletions
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39
src/arch/x86/isa/microops/mediaop.isa
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@ -870,6 +870,45 @@ let {{
FpDestReg.uqw = result;
'''
class Msubi(MediaOp):
code = '''
assert(srcSize == destSize);
int size = srcSize;
int sizeBits = size * 8;
int items = (ext & 0x1) ? 1: (sizeof(FloatRegBits) / size);
uint64_t result = FpDestReg.uqw;
for (int i = 0; i < items; i++) {
int hiIndex = (i + 1) * sizeBits - 1;
int loIndex = (i + 0) * sizeBits;
uint64_t arg1Bits = bits(FpSrcReg1.uqw, hiIndex, loIndex);
uint64_t arg2Bits = bits(FpSrcReg2.uqw, hiIndex, loIndex);
uint64_t resBits = arg1Bits - arg2Bits;
if (ext & 0x2) {
if (arg2Bits > arg1Bits) {
resBits = 0;
} else if (!findCarry(sizeBits, resBits,
arg1Bits, ~arg2Bits)) {
resBits = mask(sizeBits);
}
} else if (ext & 0x4) {
int arg1Sign = bits(arg1Bits, sizeBits - 1);
int arg2Sign = !bits(arg2Bits, sizeBits - 1);
int resSign = bits(resBits, sizeBits - 1);
if ((arg1Sign == arg2Sign) && (arg1Sign != resSign)) {
if (resSign == 0)
resBits = (1 << (sizeBits - 1));
else
resBits = mask(sizeBits - 1);
}
}
result = insertBits(result, hiIndex, loIndex, resBits);
}
FpDestReg.uqw = result;
'''
class Mmuli(MediaOp):
code = '''
int srcBits = srcSize * 8;