From: Krzysztof Pyrkosz via ffmpeg-devel <ffmpeg-devel@ffmpeg.org>
To: ffmpeg-devel@ffmpeg.org
Cc: Krzysztof Pyrkosz <ffmpeg@szaka.eu>
Subject: [FFmpeg-devel] [PATCH 2/2] avcodec/aarch64/ac3dsp_neon.S: Optimize ac3_sum_square_butterfly_int32_neon
Date: Fri, 28 Feb 2025 22:21:50 +0100
Message-ID: <20250228212148.11560-4-ffmpeg@szaka.eu> (raw)
In-Reply-To: <20250228212148.11560-2-ffmpeg@szaka.eu>
Before and after:
A78
ac3_sum_square_bufferfly_int32_neon: 484.8 ( 2.00x)
ac3_sum_square_bufferfly_int32_neon: 468.2 ( 2.08x)
A72
ac3_sum_square_bufferfly_int32_neon: 793.6 ( 1.26x)
ac3_sum_square_bufferfly_int32_neon: 527.3 ( 1.92x)
---
Instead of calculating a^2, b^2, (a+b)^2 and (a-b)^2, calculate only
a^2, b^2 and 2*a*b in each iteration and derive the latter parts from
these three at the end.
Krzysztof
libavcodec/aarch64/ac3dsp_neon.S | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/libavcodec/aarch64/ac3dsp_neon.S b/libavcodec/aarch64/ac3dsp_neon.S
index b2ac9edc55..2128eab528 100644
--- a/libavcodec/aarch64/ac3dsp_neon.S
+++ b/libavcodec/aarch64/ac3dsp_neon.S
@@ -80,21 +80,20 @@ function ff_ac3_sum_square_butterfly_int32_neon, export=1
movi v0.2d, #0
movi v1.2d, #0
movi v2.2d, #0
- movi v3.2d, #0
1: ld1 {v4.2s}, [x1], #8
ld1 {v5.2s}, [x2], #8
- add v6.2s, v4.2s, v5.2s
- sub v7.2s, v4.2s, v5.2s
- smlal v0.2d, v4.2s, v4.2s
- smlal v1.2d, v5.2s, v5.2s
- smlal v2.2d, v6.2s, v6.2s
- smlal v3.2d, v7.2s, v7.2s
subs w3, w3, #2
+ smlal v0.2d, v4.2s, v4.2s // sum of a^2
+ smlal v1.2d, v5.2s, v5.2s // sum of b^2
+ sqdmlal v2.2d, v4.2s, v5.2s // sum of 2ab
b.gt 1b
addp d0, v0.2d
addp d1, v1.2d
addp d2, v2.2d
- addp d3, v3.2d
+ sub d3, d0, d2 // a^2 + b^2 - 2ab
+ add d2, d0, d2
+ add d3, d3, d1 // a^2 + b^2 + 2ab
+ add d2, d2, d1
st1 {v0.1d-v3.1d}, [x0]
ret
endfunc
--
2.47.2
_______________________________________________
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".
prev parent reply other threads:[~2025-02-28 21:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-28 21:21 [FFmpeg-devel] [PATCH 1/2] avcodec/aarch64/ac3dsp_neon.S: Optimize ac3_extract_exponents Krzysztof Pyrkosz via ffmpeg-devel
2025-02-28 21:21 ` Krzysztof Pyrkosz via ffmpeg-devel [this message]
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=20250228212148.11560-4-ffmpeg@szaka.eu \
--to=ffmpeg-devel@ffmpeg.org \
--cc=ffmpeg@szaka.eu \
/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