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Code Issues Releases Wiki Activity

An optimized division corner case

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This commit is contained in:
caheckman 2020-08-04 15:25:21 -04:00
parent 90f6b5c7e5
commit 77b1a6bf4b
3 changed files with 89 additions and 15 deletions
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21
Ghidra/Features/Decompiler/src/decompile/cpp/op.cc
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@ -529,7 +529,22 @@ uintb PcodeOp::getNZMaskLocal(bool cliploop) const
break;
case CPUI_SUBPIECE:
resmask = getIn(0)->getNZMask();
resmask >>= 8*getIn(1)->getOffset();
sz1 = (int4)getIn(1)->getOffset();
if ((int4)getIn(0)->getSize() <= sizeof(uintb)) {
if (sz1 < sizeof(uintb))
resmask >>= 8*sz1;
else
resmask = 0;
}
else { // Extended precision
if (sz1 < sizeof(uintb)) {
resmask >>= 8*sz1;
if (sz1 > 0)
resmask |= fullmask << (8*(sizeof(uintb)-sz1));
}
else
resmask = fullmask;
}
resmask &= fullmask;
break;
case CPUI_PIECE:
@ -540,11 +555,11 @@ uintb PcodeOp::getNZMaskLocal(bool cliploop) const
case CPUI_INT_MULT:
val = getIn(0)->getNZMask();
resmask = getIn(1)->getNZMask();
sz1 = mostsigbit_set(val);
sz1 = (size > sizeof(uintb)) ? 8*size-1 : mostsigbit_set(val);
if (sz1 == -1)
resmask = 0;
else {
sz2 = mostsigbit_set(resmask);
sz2 = (size > sizeof(uintb)) ? 8*size-1 : mostsigbit_set(resmask);
if (sz2 == -1)
resmask = 0;
else {