auto NumLeadingZeroes = std::min(KnownZero.countLeadingOnes(),
KnownZero2.countLeadingOnes());
AB = ~APInt::getHighBitsSet(BitWidth, NumLeadingZeroes);
auto NumLeadingZeroes = std::min(KnownZero.countLeadingOnes(),
KnownZero2.countLeadingOnes());
AB = ~APInt::getHighBitsSet(BitWidth, NumLeadingZeroes);