[Bug middle-end/50481] builtin to reverse the bit order

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481

--- Comment #38 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
define_peephole2 IMHO should be able to fix this up, but I have no idea what
else could do that.