Issue detecting AVX architecture on MacOS

[jatinchowdhury18]

I've run into some strange behaviour with a little test program that I'm writing, where xsimd::available_architectures() correctly detects that the CPU supports AVX2 instructions but does not detect that the CPU also supports AVX instructions.

I believe the CPU does in fact support AVX since when I run sysctl -a | grep machdep.cpu, I see:

Another library that I use regularly has a similar implementation that appears to give the correct result. I'd be happy to test out a potential fix, but I'm not sure I'd feel comfortable touching that part of the code myself, since I'd probably break more things than I would fix.

[JohanMabille]

Thanks for reporting!

[jatinchowdhury18]

Awesome, thank you!