> +/* FIXME: We don't allow vectorize "__builtin_popcountll" yet since it needs > "vec_pack_trunc" support > + and such pattern may cause inferior codegen. > + We will enable "vec_pack_trunc" when we support reasonable vector > cost model. */
Wait, why do we need vec_pack_trunc for popcountll? For me vectorizing it "just works" when the output is a uint64_t just like the standard name demands. If you're referring to something else, please detail in the comment. Regards Robin
