Implementations check OK.
             Rate   csebe  moritz resubst bitwise
csebe     81457/s      --    -78%    -88%    -92%
moritz   377674/s    364%      --    -45%    -63%
resubst  686400/s    743%     82%      --    -33%
bitwise 1030128/s   1165%    173%     50%      --