[Not all the world is C++ -- I'm glad to say!] Note that OpenBLAS doesn't have avx512 kernels, and the fallback to avx2 (unreleased) is a factor of three slowe

[Not all the world is C++ -- I'm glad to say!] Note that OpenBLAS doesn't have avx512 kernels, and the fallback to avx2 (unreleased) is a factor of three slower than MKL dgemm on Knights Landing. It looks as if the next release of BLIS will remedy the lack of free BLAS avx512 support with micro-architecture dynamic dispatch which includes fairly competitive avx512 (>80% of MKL dgemm on KNL). I don't know about the competition on non-x86 architectures, but BLIS currently has more limited support than OpenBLAS.