Cannot install on centos-7 gcc-4.8.5 missing -fopenmd-simd

[howff]

Cannot install on centos-7 x86_64 with gcc-4.8.5 because it's trying to use the gcc option -fopenmp-simd which is unknown.

I tried BLIS_ARCH=generic with the same result.

[adrianeboyd]

I think the easiest option is to use blis==0.4.1 instead.

We could use some better documentation about supported compiler versions. It looks like you'd need gcc 4.9.1+ for this option, and there may be additional unsupported options in the hard-coded build script setup, which is problematic for cases like this. I know that I've tested back to gcc-5, and the CI currently tests clang 9.0 and relatively up-to-date releases of gcc-7, gcc-8, and gcc-9.