ffmpeg | branch: master | Krzysztof Pyrkosz <ffm...@szaka.eu> | Fri Feb 28 22:21:50 2025 +0100| [e8d4c559871ef93fc94a8efb8144f1738eba4c62] | committer: Martin Storsjö
avcodec/aarch64/ac3dsp_neon.S: Optimize ac3_sum_square_butterfly_int32_neon 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. 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) Signed-off-by: Martin Storsjö <mar...@martin.st> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e8d4c559871ef93fc94a8efb8144f1738eba4c62 --- 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 7e97cc39f7..c28e2082a9 100644 --- a/libavcodec/aarch64/ac3dsp_neon.S +++ b/libavcodec/aarch64/ac3dsp_neon.S @@ -69,21 +69,20 @@ 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 _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
