https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86735
--- Comment #12 from janus at gcc dot gnu.org --- (In reply to Dominique d'Humieres from comment #11) > Thanks for the explanation. Note that > > % gfcp pr86735.f90 -Ofast -march=skylake -Wall -Wextra -fcheck=all That probably just means that -fcheck prevents the optimization passes from applying AVX512 instructions. Please cut the noise!