https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96918
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Or the generic code could try to expand vector rotates by multiplies of BITS_PER_UNIT as vector permutations, perhaps only if there is no optab for it. Or trying to expand both permutation and rotate and determine at expansion time using costs which sequence is cheaper.
