RhodeCode

        num = shift - 1;

        while (num--) {

          curr[0] = (((curr[0] & hiMask) | (curr[-1] & loMask)) >> 1) ^

            curr[length - shift] ^ mask[curr[-1] & 1ul];

          --curr;

        }

          curr[length - shift] ^ mask[curr[length - 1] & 1ul];

      }

      Word *current;