[x265] How can I enable the AVX2 version of DCT and IDCT?

[Dnyaneshwar Gorade]

Hi Ximing,

If your machine (and OS also) supports AVX2 instruction set then you are
already compiling and using AVX2 version of DCT functions.
x265 automatically detects & sets all assembly primitives to highest/latest
available instruction sets.

When you run encoder, you can check command prompt output if cpu
capabilities info shows AVX2 instruction set or not.
You can get the source code of DCT AVX2 functions in dct8.asm file.


Regards,
Dnyaneshwar

On Wed, Sep 16, 2015 at 6:25 PM, Ximing Cheng <chengximing1989 at gmail.com>
wrote:

> I read the source code of the /source/common/vec/dct-sse3.cpp and I found
> the comments said "Note: We have AVX2 assembly for these functions, but
> since AVX2 is still somewhat rare on end-user PCs we still compile and link
> these SSE3 intrinsic SIMD functions".
>
> But now both my PC and server support Intel AVX2 instruction set. If I
> want to compile these functions with AVX2 assembly, where to find the AVX2
> version of source code of these functions?
>
> Thanks!
>
> _______________________________________________
> x265-devel mailing list
> x265-devel at videolan.org
> https://mailman.videolan.org/listinfo/x265-devel
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/x265-devel/attachments/20150916/10ad35dc/attachment.html>