Don't add py-cpuinfo

[JDBetteridge]

This is just an idea for how to avoid using the py-cpuinfo package.

To be completely honest I'm not sure this is even necessary:

• It will only work on x86_64 architectures (this is also true of py-cpuinfo)
• It feels hacky
• The default of PYOP2_SIMD_WIDTH=4 covers almost all use cases (with the exception of AVX512*)

If a user really wants to change the SIMD width used within PYOP2 they should manually set PYOP2_SIMD_WIDTH, I don't really think we should try and sniff this value.

*My impression is that using AVX512 normally incurs a performance penalty due to the CPU having to downclock. A benchmark might convince me otherwise.

[connorjward]

I agree. I think defaulting to 4, and allowing users to change things, is a completely reasonable approach here.

Are there ever circumstances where this might cause a breakage?

[wence-]

I agree. I think defaulting to 4, and allowing users to change things, is a completely reasonable approach here.

Are there ever circumstances where this might cause a breakage?

M1 cores have 128bit vectors. But I think that going for four wide (effectively 256bit vectors) would be fine.

[sv2518]

Thanks, Jack!