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X86: Implement a media floating point subtract microop.

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This commit is contained in:
Gabe Black 2009-08-17 18:36:18 -07:00
parent 49c2610c04
commit 9fee8b75aa
1 changed files with 46 additions and 0 deletions
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46
src/arch/x86/isa/microops/mediaop.isa
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@ -620,4 +620,50 @@ let {{
}
FpDestReg.uqw = result;
'''
class Msubf(MediaOp):
code = '''
union floatInt
{
float f;
uint32_t i;
};
union doubleInt
{
double d;
uint64_t i;
};
assert(srcSize == destSize);
int size = srcSize;
int sizeBits = size * 8;
assert(srcSize == 4 || srcSize == 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;
if (size == 4) {
floatInt arg1, arg2, res;
arg1.i = arg1Bits;
arg2.i = arg2Bits;
res.f = arg1.f - arg2.f;
resBits = res.i;
} else {
doubleInt arg1, arg2, res;
arg1.i = arg1Bits;
arg2.i = arg2Bits;
res.d = arg1.d - arg2.d;
resBits = res.i;
}
result = insertBits(result, hiIndex, loIndex, resBits);
}
FpDestReg.uqw = result;
'''
}};