From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.ffmpeg.org (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id 5124F4AFAF for ; Wed, 21 May 2025 07:46:58 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id C7EEE68CC39; Wed, 21 May 2025 10:46:53 +0300 (EEST) Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTPS id 686C368C9FA for ; Wed, 21 May 2025 10:46:47 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 9A8C5441CD for ; Wed, 21 May 2025 07:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1747813606; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DesPXOng2iaoYvY/8VvRGYNC4t/jUSzo+eP9Pi54NU0=; b=ngFCsB2SWVYqewc/k1ZECSuBeGzJTBbtfxmHPudzSoAk1iafO2nezpBU6H4jh+5iB5PrKE rOoqbisNh/Jl/7mgKEX0gPS6G4VPlb7PnhJP3w257wIgpuiTVxG5PQBXOtaP28MzihMjR0 TF7we72DXA16TcwDRrVru9gbewntowd3nliPgvwopSebc9z3GE0hRUqnSMrB3zdYoMJuo6 Pnxg3wspoyucSzTtdoJfbbd/EwdIlRrGtL2nKImm6EW2Jixi48ytX2kT1wedNHT4BhjTAf BE7USGaKcKTiyQzMOojRwpO3P6voaSBTyJX/1YsCT2wwdEuZxl0du+oougOwZA== Date: Wed, 21 May 2025 09:46:45 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20250521074645.GM29660@pb2> References: <20250521061750.54882-1-jiawei@iscas.ac.cn> MIME-Version: 1.0 In-Reply-To: <20250521061750.54882-1-jiawei@iscas.ac.cn> X-GND-State: clean X-GND-Score: -85 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtddtgddvhedvucdltddurdegfedvrddttddmucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenfghrlhcuvffnffculdduhedmnecujfgurhepfffhvffukfhfgggtuggjsehgtderredttddvnecuhfhrohhmpefoihgthhgrvghlucfpihgvuggvrhhmrgihvghruceomhhitghhrggvlhesnhhivgguvghrmhgrhigvrhdrtggtqeenucggtffrrghtthgvrhhnpeffledtfeevfeffheeuuefhtdejieelueeftdeitdfgheetgefffeefteekffdthfenucffohhmrghinhepfhhfmhhpvghgrdhorhhgnecukfhppeeguddrieeirdeijedruddufeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeguddrieeirdeijedruddufedphhgvlhhopehlohgtrghlhhhoshhtpdhmrghilhhfrhhomhepmhhitghhrggvlhesnhhivgguvghrmhgrhigvrhdrtggtpdhnsggprhgtphhtthhopedupdhrtghpthhtohepfhhfmhhpvghgqdguvghvvghlsehffhhmphgvghdrohhrgh X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] gcc: Remove auto-vectorization limitation. 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: , Reply-To: FFmpeg development discussions and patches Content-Type: multipart/mixed; boundary="===============8554465004150332071==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============8554465004150332071== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="FZB11itk5qzDXri3" Content-Disposition: inline --FZB11itk5qzDXri3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 21, 2025 at 02:17:50PM +0800, Jiawei wrote: > This patch modifies the FFmpeg build system to remove the explicit disabl= ing > of GCC's auto-vectorization feature. >=20 > Modern GCC versions (>=3D 10.0) have demonstrated stable auto-vectorizati= on > capabilities through extensive optimizations in loop analysis and SIMD > code generation. The explicit -fno-tree-vectorize flag originally added > in commit 973859f (2009) to workaround early GCC vectorization instability > is no longer necessary. >=20 > Key improvements justifying this change: > 1. Enhanced heuristics for loop vectorization cost models > 2. Mature handling of alignment and memory access patterns > 3. Robust fallback mechanisms for unsupported architectures >=20 > This change allows FFmpeg to benefit from automated SIMD optimizations > when built with -O3 optimization level, particularly improving > performance on x86_64 (AVX), ARM64 (SVE) and RISC-V(RVV) architectures. >=20 > [1] https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/973859f5230e77beea7bb= 59dc081870689d6d191 >=20 > --- > configure | 1 - > 1 file changed, 1 deletion(-) >=20 > diff --git a/configure b/configure > index 3730b0524c..b9e95ce4ec 100755 > --- a/configure > +++ b/configure > @@ -7656,7 +7656,6 @@ if enabled icc; then > disable aligned_stack > fi > elif enabled gcc; then > - check_optflags -fno-tree-vectorize > check_cflags -Werror=3Dformat-security > check_cflags -Werror=3Dimplicit-function-declaration > check_cflags -Werror=3Dmissing-prototypes Your text speaks about this change being ok in a gcc version dependant way Your patch has no gcc version dependancy If you claim that all issues where solved, please show the issues happening in version v and no longer happening in w>v . Then it make sense to change the flags for version w Thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB When the tyrant has disposed of foreign enemies by conquest or treaty, and there is nothing more to fear from them, then he is always stirring up some war or other, in order that the people may require a leader. -- Plato --FZB11itk5qzDXri3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEKAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCaC2E5QAKCRBhHseHBAsP q9aqAJ0UmIoG2XZv3SvtwaGXb9UgGSyKMgCfQ6CEU0YMZd3/ptTryqe2Q1OLn9g= =RHee -----END PGP SIGNATURE----- --FZB11itk5qzDXri3-- --===============8554465004150332071== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ 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". --===============8554465004150332071==--