x/sys/cpu: add support for detecting AVX-512

[clausecker]

I would like to detect the availability of AVX-512 and its subsets (F, CD, VL, BW, DQ, IFMA, VBMI, ...) using the golang.org/x/sys/cpu package. However, no such flags are available. Please add a way to detect the availability of AVX-512 and its specific sub features. If desired, I can try writing a patch for this myself.

[randall77]

A patch would be great, thanks.

[anton-kuklin]

@fuzxxl Hi, if you will change your mind about doing it by yourself - plz ping me, I will handle this.

[clausecker]

@justplesh If you would like to do this I would be very happy. Gives me more time to spend writing my paper.

[anton-kuklin]

@clausecker ok, so I'll work on this

[clausecker]

@justplesh Any progress on this one?

[anton-kuklin]

@clausecker will start in a few days

[clausecker]

@justplesh If it's in more than week, I think I'll just do it myself. I have been holding up writing AVX-512 code for two weeks now and would like to begin soon-ish.

[anton-kuklin]

@clausecker I'll try this weekend

[gopherbot]

Change https://golang.org/cl/257937 mentions this issue: cpu: add support for detecting AVX-512

[anton-kuklin]

@clausecker so, I've implemented the patch, hopefully, it will be merged soon

[martisch]

Note that osxsave needs to be checked and zmm register support (similar to avx and ymm registers) before allowing use of AVX-512.

[anton-kuklin]

Note that osxsave needs to be checked and zmm register support (similar to avx and ymm registers) before allowing use of AVX-512.

If I understood correctly, we can just check if AVX is supported. As it is already checked :)