https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91940
--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Only 16-bit byteswap has the r>> 8 canonical form, larger byteswaps don't. Larger byteswaps certainly aren't rotates, but just permutes. So, if the vectorizer doesn't try that already, it should try to vectorize bswap32, bswap64 etc. as a permutation.
