https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91695
Bug ID: 91695 Summary: [X86] get_available_features only sets FEATURE_GFNI and FEATURE_VPCLMULQDQ when avx512_usable is true Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: libgcc Assignee: unassigned at gcc dot gnu.org Reporter: craig.topper at gmail dot com Target Milestone: --- GFNI has instructions that have legacy SSE-like encodings. It also has VEX and EVEX encodings. VPCLMULQDQ has a VEX encoding for 256-bit and EVEX encoding 256-bit and 512-bit. So these features are usable without AVX512. It probably makes sense to qualify VPCLMULQDQ with avx_usable since it requires at least ymm registers.