[FFmpeg-devel] [PATCH] configure: set IceLake-AVX512 as the minimum baseline

[Joel Linn]

Hello,

On 2021-08-18 12:40, Ronald S. Bultje wrote:
> 
> I don't think you can make that decision single-handedly. doesn't it 
> depend
> on the situation, and shouldn't individual users and/or developers be 
> able
> to make that decision themselves?
> 

I agree, not all AVX512 instructions slow down those CPUs and heat the 
room; especially when used only occasionally.

True, the AVX512 feature matrix is a mess but there are a lot of 
instructions which simplify work with 256bit registers as well because 
the restriction on 128bit lanes was lifted and a lot of new functions 
where added.
It was shown that the occasional use of AVX512 instructions does not 
significantly throttle CPUs. For example in a larger algorithm, 
replacing sequences of AVX permute and shuffle instructions with single 
AVX512 permute(ex)s could thus aid all AVX512 systems.