https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119357
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Slightly more simplified typedef char V __attribute__((vector_size (16))); void foo (V *p) { if (__builtin_ia32_pmovmskb128 (*p == 0) != 65535) __builtin_abort (); } Just -O2 -mavx512{bw,vl} is needed.