[FFmpeg-devel] [PATCH 2/5] configure: Add detection of assembler support for SVE/SVE2

[Martin Storsjö]

On Tue, 17 Sep 2024, Martin Storsjö wrote:

> It turns out that recent versions of MS armasm64 does support some
> SVE instructions, but not all of them. Test for one of the
> instructions that it currently doesn't support.
>
> ---
>
> Just as disclaimer, I'm not currently actively planning on writing
> SVE/SVE2 optimizations. However, related projects such as x264 and
> dav1d do have a few functions using these extensions, so we might just
> as well add the framework support for these features in ffmpeg
> anyway, as functions needing this support will come sooner or later
> anyway.
>
> In the related projects, there's no really use of longer vectors
> (as there's very little such HW available anyway), but SVE gives
> widening loads (used in a couple places in x264) and 16 bit dot
> products (used in dav1d), which can be useful with 128 bit vectors.
> ---
> configure               | 14 +++++++++++++-
> ffbuild/arch.mak        |  2 ++
> libavutil/aarch64/asm.S | 18 ++++++++++++++++++
> 3 files changed, 33 insertions(+), 1 deletion(-)

Planning on pushing this set later today.

// Martin