exchangeLR method
Swap bits across the left and right words
Implementation
void exchangeLR(int offset, int mask) {
final int t =
(((_lBlock.rightShift32(offset)).toSigned(32) ^ _rBlock) & mask)
.toSigned(32);
(_rBlock ^= t).toSigned(32);
_lBlock ^= (t << offset).toSigned(32);
}