[PATCH] x86: Update CPU feature detection

Florian Weimer fweimer@redhat.com
Thu Jun 18 08:09:44 GMT 2020


* H. J. Lu via Libc-alpha:

> 1. Add COMMON_CPUID_INDEX_7_ECX_1 for AVX512_BF16.

Do you expect similar changes in the future?  This changes the layout of
struct cpu_features.

If __x86_get_cpu_features is exported, such a change will require a new
symbol version for __x86_get_cpu_features and can therefore only be made
at a release boundary.  Even then, statically linked libraries will
silently use the old layout of struct cpu_features, silently giving
incorrect results if linked against a newer glibc version.

Thanks,
Florian



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