From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id B51224C61A for ; Thu, 23 Jan 2025 21:31:27 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 7F44568B7CC; Thu, 23 Jan 2025 23:31:23 +0200 (EET) Received: from szaka.eu (szaka.eu [144.217.86.229]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 83C0B68A8B1 for ; Thu, 23 Jan 2025 23:31:16 +0200 (EET) Date: Thu, 23 Jan 2025 22:31:05 +0100 To: FFmpeg development discussions and patches Message-ID: References: <20250119173259.1533-2-ffmpeg@szaka.eu> <8111ca5d-4d1c-15d2-bd32-e74959c2194f@martin.st> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <8111ca5d-4d1c-15d2-bd32-e74959c2194f@martin.st> Subject: Re: [FFmpeg-devel] [PATCH] avutil/aarch64/float_dsp_neon: Refactor ff_vector_fmul_add_neon X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Krzysztof Pyrkosz via ffmpeg-devel Reply-To: FFmpeg development discussions and patches Cc: Krzysztof Pyrkosz Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Sun, Jan 19, 2025 at 10:57:57PM +0200, Martin Storsj=F6 wrote: > On Sun, 19 Jan 2025, Krzysztof Pyrkosz via ffmpeg-devel wrote: > = > > Removed a branch, unrolled loop. Speed increase bumped from 3.95 to 5.6= 0. > = > On what core is that? Please quote the actual output including the absolu= te > numbers. > = > I'm getting much more inconclusive numbers for this one: > = > Before: Cortex A53 A72 A73 A78 > vector_fmul_add_neon: 620.0 257.2 624.5 162.8 > After: > vector_fmul_add_neon: 767.0 259.2 767.5 110.5 > = > This seems to make things quite a lot slower on 2 of these 4 cores. On the > A78, I'm getting numbers that look like yours though. > = > So while it makes things better on one kind of core, it also regresses > things quite a bit on others, so I'm not quite as convinced about this on= e. Indeed, I conducted the tests and gathered the benchmark results on the A78, Rock5B to be more specific. > Doing that change, i.e. > = > fmla v4.4s, v0.4s, v2.4s > fmla v5.4s, v1.4s, v3.4s > + subs w4, w4, #16 > stp q4, q5, [x0], #32 > - sub w4, w4, #16 > - cbnz w4, 1b > + b.gt 1b > ret > = > has this effect on numbers: > = > Before: Cortex A53 A72 A73 A78 > vector_fmul_add_neon: 767.0 259.2 769.5 109.0 > After: > vector_fmul_add_neon: 751.0 254.5 751.0 109.2 > = Below are my results for different cores I have lying around. First is the mainline version, second uses the patch from the original email, third improves things by reordering instructions: - vector_fmul_neon A72 A78 Thinkpad x13s Mainline: 218.42 114.7 62.85 Original patch: 223.92 86.16 64.77 Reordered instr: 221.75 85.66 61.16 - vector_fmul_add_neon A72 A78 Thinkpad x13s Mainline: 269.49 163.43 84.48 Original patch: 269.42 114.16 85.31 Reordered instr: 266.92 111.62 85.04 > That makes things a little bit better on A53,A72,A73, but it's still over= all > a notable regression on the A53 and A73. Let's skip this patch and two others then, thank you for the review. Krzysztof _______________________________________________ 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".