As Chris suggested, handle the situation if ShAmt larger than BitWidth,

otherwise, opt might crash.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52041 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Zhou Sheng 2008-06-06 08:32:05 +00:00
parent 9c3c221364
commit cc41940dff

View File

@ -1236,7 +1236,7 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, APInt DemandedMask,
// If the input sign bit is known to be zero, or if none of the top bits
// are demanded, turn this into an unsigned shift right.
if (BitWidth == ShiftAmt || RHSKnownZero[BitWidth-ShiftAmt-1] ||
if (BitWidth <= ShiftAmt || RHSKnownZero[BitWidth-ShiftAmt-1] ||
(HighBits & ~DemandedMask) == HighBits) {
// Perform the logical shift right.
Value *NewVal = BinaryOperator::CreateLShr(