https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99396
--- Comment #4 from cqwrteur <unlvsur at live dot com> ---
(In reply to Andrew Pinski from comment #3)
> (In reply to cqwrteur from comment #2)
> > I would like to see __builtin_cpp_rotl and __builtin_cpp_rotr to allow more
> > aggressive optimizations since rotl and rotr are so important for
> > cryptography.
>
> You don't need them.
> The following code will already produce the rotate instruction:
> auto f3(std::size_t v, int t)
> {
> return (v<<t) | (v>>(sizeof(v)*8 - t));
> }
>
> Note std::rotl/std::rotr has specific behavior dealing with 0 and negative
> values and all.
but if it is constant, it would get optimized to just ror or rol
