Why does gnutls need to judge whether it supports FMA when detecting the extended instruction set AVX
In x86-common.c, Need to satisfy OSXSAVE, FMA and MOVBE are all 1 in order to use AVX. But in intel manual, only need to check OSXSAVE and AVX feature flags.
When we set environment variable GNUTLS_CPUID_OVERRIDE to AVX, it does not run the AVX extended instruction set.
Edited by zzjianhui