http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50160 --- Comment #10 from Jonathan Schmidt-Dominé <devel@the-user.org> 2011-08-23 19:15:20 UTC --- There seem to be a lot of tricks to achieve that: http://graphics.stanford.edu/~seander/bithacks.html#ReverseByteWith64BitsDiv