[llvm-dev] Use Galois field New Instructions (GFNI) to combine affine instructions

[Adrien Guinet via llvm-dev]

On 5/18/20 8:24 PM, Craig Topper wrote:
> I can tell you that your avx512 issue is that v64i8 gfni instructions also
> require avx512bw to be enabled to make v64i8 a supported type. The C
> intrinsics handling in the front end know this rule. But since you
> generated your own intrinsics you bypassed that.

Indeed that's the issue... I was stick with what Intel announces here
(https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=gf2p&expand=2907), but
I guess I should have checked the C intrinsics.

I will fix my code to verify the presence of avx512bw if I ever need v64i8.

Thanks for the hint!