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authorGabe Black <gblack@eecs.umich.edu>2009-08-05 03:01:49 -0700
committerGabe Black <gblack@eecs.umich.edu>2009-08-05 03:01:49 -0700
commitd265f7683e761207a60d9187324846aedf674c84 (patch)
tree6af4d0c31018863baec8ff63f82f2488d1d34af1
parent77dc6b33ee836e030a2e9c230b8ce67e0e39c322 (diff)
downloadgem5-d265f7683e761207a60d9187324846aedf674c84.tar.xz
X86: Handle rotate right with carry instructions that go all the way around or more.
-rw-r--r--src/arch/x86/isa/microops/regop.isa16
1 files changed, 10 insertions, 6 deletions
diff --git a/src/arch/x86/isa/microops/regop.isa b/src/arch/x86/isa/microops/regop.isa
index 0bf3420b8..477034224 100644
--- a/src/arch/x86/isa/microops/regop.isa
+++ b/src/arch/x86/isa/microops/regop.isa
@@ -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);