Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
 help / color / mirror / Atom feed
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] avutil/aarch64/float_dsp_neon: Refactor ff_butterflies_float_neon
Date: Sun, 19 Jan 2025 19:07:07 +0100
Message-ID: <20250119180706.3075-2-ffmpeg@szaka.eu> (raw)

Modified the main loop to handle 8 floats in one go. A special case of
length not being multiple of 8 is handled at the beginning. The speed
increased from 3.90 to 4.50.

Krzysztof

---
 libavutil/aarch64/float_dsp_neon.S | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/libavutil/aarch64/float_dsp_neon.S b/libavutil/aarch64/float_dsp_neon.S
index 35e2715b87..f99cc2e6b2 100644
--- a/libavutil/aarch64/float_dsp_neon.S
+++ b/libavutil/aarch64/float_dsp_neon.S
@@ -178,14 +178,28 @@ function ff_vector_fmul_reverse_neon, export=1
 endfunc
 
 function ff_butterflies_float_neon, export=1
-1:      ld1             {v0.4s}, [x0]
-        ld1             {v1.4s}, [x1]
-        subs            w2,  w2,  #4
-        fsub            v2.4s,   v0.4s,  v1.4s
-        fadd            v3.4s,   v0.4s,  v1.4s
-        st1             {v2.4s}, [x1],   #16
-        st1             {v3.4s}, [x0],   #16
-        b.gt            1b
+        tst            w2, #4
+        b.eq           bf8
+        ldr            q0, [x0]
+        ldr            q1, [x1]
+        fadd           v2.4s, v0.4s, v1.4s
+        fsub           v3.4s, v0.4s, v1.4s
+        str            q2, [x0], #16
+        str            q3, [x1], #16
+        sub            w2, w2, #4
+        cbnz           w2, bf8
+        ret
+bf8:
+        ldp            q0, q1, [x0]
+        ldp            q4, q5, [x1]
+        fadd           v2.4s, v0.4s, v4.4s
+        fadd           v3.4s, v1.4s, v5.4s
+        stp            q2, q3, [x0], #32
+        fsub           v2.4s, v0.4s, v4.4s
+        fsub           v3.4s, v1.4s, v5.4s
+        stp            q2, q3, [x1], #32
+        sub            w2, w2, #8
+        cbnz           w2, bf8
         ret
 endfunc
 
-- 
2.45.2

_______________________________________________
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".

             reply	other threads:[~2025-01-19 18:14 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-19 18:07 Krzysztof Pyrkosz via ffmpeg-devel [this message]
2025-01-19 21:28 ` Martin Storsjö

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=20250119180706.3075-2-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