From: "Rémi Denis-Courmont" <remi@remlab.net>
To: ffmpeg-devel@ffmpeg.org
Subject: Re: [FFmpeg-devel] [PATCH v4] libavcodec/riscv:add RVV optimized idct_32x32_8 for HEVC
Date: Sat, 24 May 2025 19:18:46 +0300
Message-ID: <2001553.PYKUYFuaPT@basile.remlab.net> (raw)
In-Reply-To: <20250520075806.138222-1-daichengrong@iscas.ac.cn>
Le tiistaina 20. toukokuuta 2025, 10.58.06 Itä-Euroopan kesäaika
daichengrong@iscas.ac.cn a écrit :
> From: daichengrong <daichengrong@iscas.ac.cn>
>
> Since there are no comments for v2 and v3, we have continued to optimize
> according to the comments of v1. We spilled the slide to memory to help
> improve performance,and optimized the extraction of elements from vector
> registers.
You still seem to be flip-flopping values in X registers. You may need to go
easier on macros to get a better view of the actual generated code.
Also it seems that this uses half-vectors a lot. I am not sure if this can be
avoided, but typically that leads to very poor performance.
Also you're resetting `vl` with its current value, which can hurt performance
depending on the implementation. If you don't need to change `vl`, then use
`zero`.
Lastly, you seem to be changing vtype when it's not actually needed, e.g.:
vsetvli zero, 4, e16, mf2...
...
vsetvli zero, 4, e32, mf1...
vse32.v ...
--
德尼-库尔蒙‧雷米
Hagalund ny stad, f.d. Finska republik Nylands
_______________________________________________
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:[~2025-05-24 16:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-20 7:58 daichengrong
2025-05-24 16:18 ` Rémi Denis-Courmont [this message]
2025-05-30 7:40 ` [FFmpeg-devel] [PATCH v5] " daichengrong
2025-06-02 20:13 ` Rémi Denis-Courmont
2025-06-06 9:26 ` [FFmpeg-devel] [PATCH v6] libavcodec/riscv: add " daichengrong
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=2001553.PYKUYFuaPT@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