https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67406
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> --- -mfma is an independent ISA option, not part of -mavx2, there could be CPUs with AVX2, but without FMA, so it can't be enabled. As for AVX512 cloning, what ISAs we clone to is part of the ABI, and at the time when the support has been added the AVX512 support hasn't been there yet. Furthermore, even on the current trunk, the support for the integral masks is really bad, and the ABI says that the masks for AVX512 are passed in general purpose integral registers.
