https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89929
--- Comment #15 from Martin Liška <marxin at gcc dot gnu.org> --- @Nikolay: As discussed in https://gcc.gnu.org/ml/gcc-patches/2019-04/msg00416.html email thread, we reached the following consensus with H.J: - As any AVX512 extensions (apart from AVX512F) can be enabled individually, it's difficult to come up with priorities in dispatcher. - We don't have a syntax for target_clone attribute where one would say e.g. avx512f+avx512cd+avx512er. - So that we would reject these (AVX512* except AVX512F) in target_clone attribute and we recommend to use rather. target_clones(arch=skylake,arch=skylake-avx512,arch=cannonlake,arch=icelake-client,arch=icelake-server, ..) - Using that one can cover used AVX512 ISA combinations for existing CPUs Does it work for you Nikolay?