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X86: Handle rotate right with carry instructions that go all the way around or more.

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This commit is contained in:
Gabe Black 2009-08-05 03:01:49 -07:00
parent 77dc6b33ee
commit d265f7683e
1 changed files with 10 additions and 6 deletions
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16
src/arch/x86/isa/microops/regop.isa
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@ -762,13 +762,14 @@ let {{
code = '''
uint8_t shiftAmt =
(op2 & ((dataSize == 8) ? mask(6) : mask(5)));
if(shiftAmt)
uint8_t realShiftAmt = shiftAmt % (dataSize * 8 + 1);
if(realShiftAmt)
{
CCFlagBits flags = ccFlagBits;
uint64_t top = flags.cf << (dataSize * 8 - shiftAmt);
if(shiftAmt > 1)
top |= psrc1 << (dataSize * 8 - shiftAmt + 1);
uint64_t bottom = bits(psrc1, dataSize * 8 - 1, shiftAmt);
uint64_t top = flags.cf << (dataSize * 8 - realShiftAmt);
if (realShiftAmt > 1)
top |= psrc1 << (dataSize * 8 - realShiftAmt + 1);
uint64_t bottom = bits(psrc1, dataSize * 8 - 1, realShiftAmt);
DestReg = merge(DestReg, top | bottom, dataSize);
}
else
@ -787,8 +788,11 @@ let {{
ccFlagBits = ccFlagBits | OFBit;
}
//If some combination of the CF bits need to be set, set them.
if ((ext & (CFBit | ECFBit)) && bits(SrcReg1, shiftAmt - 1))
if ((ext & (CFBit | ECFBit)) &&
(realShiftAmt == 0) ? origCFBit :
bits(SrcReg1, realShiftAmt - 1)) {
ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
}
//Use the regular mechanisms to calculate the other flags.
ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
DestReg, psrc1, op2);