https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114252
--- Comment #16 from rguenther at suse dot de <rguenther at suse dot de> --- On Thu, 7 Mar 2024, gjl at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114252 > > --- Comment #14 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- > The code in the example is not a perfect bswap, it needs additional shuffling > of bytes. The tree passes must know that bswap is not a perfect fit. There > must be *some* criterion that depends on the permutation, and when a bswap is > closer to the bswapped-permutation that a non-bswapped permutation is to the > original one. I think we only support bswap + rotate as replacement (but just use that if it matches).
