We already handled a superset check that included the known ones too and folded to a constant that may include ones. But it can also handle the case of no ones.
llvm-svn: 300093
(DemandedMask & ~RHSKnownZero))
return I->getOperand(1);
- // If all of the demanded bits in the inputs are known zeros, return zero.
- if ((DemandedMask & (RHSKnownZero|LHSKnownZero)) == DemandedMask)
- return Constant::getNullValue(VTy);
-
// If the RHS is a constant, see if we can simplify it.
if (ShrinkDemandedConstant(I, 1, DemandedMask & ~LHSKnownZero))
return I;