From: "Rémi Denis-Courmont" <remi@remlab.net>
To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Subject: Re: [FFmpeg-devel] [PATCH] lavc/vc1dsp: R-V V mspel_pixels
Date: Sun, 05 May 2024 22:26:03 +0300
Message-ID: <3559240.iIbC2pHGDl@basile.remlab.net> (raw)
In-Reply-To: <CAEa-L+tR-Ou=zqwvPnBocrEdXvSf=SXQnOP=Nm0HU5XtcghtqA@mail.gmail.com>
Le sunnuntaina 5. toukokuuta 2024, 12.18.56 EEST flow gg a écrit :
> > Does MF2 actually improve perfs over M1 here?
>
> The difference here seems very small, but when both mf2 and m1 are correct,
> the test results have only shown mf2 to be better, so I want to use mf2.
I can live with that. But this is a slippery slope because large vector sizes
would involve even smaller fractions. Then we would need to compute the value
which might negate the performance gains from fractional multipliers.
The fastest approach that I can think of is a symbolic LA (which expands to
1xAUIPC + 1xLA) to load a precomputed VTYPE value from a static variable.
Furthermore, this requires VSETVL, which precludes immediate constant VL
Indeed, the VSETIVL instruction does not exist.
AFAIU, BananaPi F3 has 256-bit vectors already now.
--
Rémi Denis-Courmont
http://www.remlab.net/
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
next prev parent reply other threads:[~2024-05-05 19:26 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-04 10:01 uk7b
2024-05-04 10:08 ` flow gg
2024-05-04 17:53 ` Rémi Denis-Courmont
2024-05-05 9:15 ` uk7b
2024-05-05 9:18 ` flow gg
2024-05-05 19:26 ` Rémi Denis-Courmont [this message]
2024-05-10 8:21 ` uk7b
2024-05-12 11:48 ` Rémi Denis-Courmont
2024-05-12 12:43 ` uk7b
2024-05-12 12:43 ` flow gg
2024-05-12 12:57 ` uk7b
2024-05-10 8:22 ` flow gg
2024-05-10 15:34 ` Rémi Denis-Courmont
2024-05-11 10:02 ` flow gg
2024-05-11 10:24 ` Rémi Denis-Courmont
2024-05-11 10:47 ` flow gg
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3559240.iIbC2pHGDl@basile.remlab.net \
--to=remi@remlab.net \
--cc=ffmpeg-devel@ffmpeg.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
This inbox may be cloned and mirrored by anyone:
git clone --mirror https://master.gitmailbox.com/ffmpegdev/0 ffmpegdev/git/0.git
# If you have public-inbox 1.1+ installed, you may
# initialize and index your mirror using the following commands:
public-inbox-init -V2 ffmpegdev ffmpegdev/ https://master.gitmailbox.com/ffmpegdev \
ffmpegdev@gitmailbox.com
public-inbox-index ffmpegdev
Example config snippet for mirrors.
AGPL code for this site: git clone https://public-inbox.org/public-inbox.git