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 B54234CF15 for ; Sat, 14 Jun 2025 22:49:48 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id A0A4A68CF3C; Sun, 15 Jun 2025 01:49:46 +0300 (EEST) Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTPS id E7F5568CB24 for ; Sun, 15 Jun 2025 01:49:44 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 4DB43432F5; Sat, 14 Jun 2025 22:49:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1749941384; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hvmnrrUoD4wZtpQQlfR8lZrDsJwEQTkGw6Of3vsCEFs=; b=PX8e8tpaZ47CR9wyNV7Uq++L2ZO9Msdva0r+MYuR+JydNYmLl+i7fKPku3LMymojIYBY+W m/IvB4t4wkT0FQbToYCPZbiTDpj5OgmWVHc0EeVsA420FlgV/SNtCl7jPMIalRZBdbC/Wr zyqTGJIJVb2rnfauqbeaAVRHuSUWxXLqLe66nRvPBduUvVvaxh/vfZ8bAa23o0NGU8wuYQ Ylj6IyqH9JBzf9Ly9JHADDmatx4PpVj+A6QpNeMnmlLd2QHCw1V9lEZ3mvBplmqywuh9Dy 14fO8B4XmTGpUvg1WO5s+t2D01gk9jEIOwNUkthGJJdoBl2ddiwz8b+doxTqNQ== Date: Sun, 15 Jun 2025 00:49:42 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20250614224942.GT5177@pb2> References: <20250613083704.6858-1-jiawei@iscas.ac.cn> MIME-Version: 1.0 In-Reply-To: X-GND-State: clean X-GND-Score: -85 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtddugddvvddtjecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnegfrhhlucfvnfffucdludehmdenucfjughrpeffhffvvefukfhfgggtuggjsehgtderredttddunecuhfhrohhmpefoihgthhgrvghlucfpihgvuggvrhhmrgihvghruceomhhitghhrggvlhesnhhivgguvghrmhgrhigvrhdrtggtqeenucggtffrrghtthgvrhhnpeeuieeitdfgvdehtddthfegvdehjeekgfejtedugfdvgeekgefgheevkeelhfeghfenucffohhmrghinhepfhhfmhhpvghgrdhorhhgnecukfhppeeguddrieeirdeijedruddufeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeguddrieeirdeijedruddufedphhgvlhhopehlohgtrghlhhhoshhtpdhmrghilhhfrhhomhepmhhitghhrggvlhesnhhivgguvghrmhgrhigvrhdrtggtpdhnsggprhgtphhtthhopedvpdhrtghpthhtohepfhhfmhhpvghgqdguvghvvghlsehffhhmphgvghdrohhrghdprhgtphhtthhopehjihgrfigvihesihhstggrshdrrggtrdgtnh X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] [PATCH v5] gcc: Don't disable '-ftree-vectorize' if gcc version higher than 13. 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 Cc: Jiawei Content-Type: multipart/mixed; boundary="===============0256631250563276479==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============0256631250563276479== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="dMK9NfDstrAqAuhj" Content-Disposition: inline --dMK9NfDstrAqAuhj Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Martin On Fri, Jun 13, 2025 at 11:42:11AM +0300, Martin Storsj=F6 wrote: > On Fri, 13 Jun 2025, Jiawei wrote: >=20 > > This patch modifies the FFmpeg build system to allow GCC to use the > > `-ftree-vectorize` flag when the compiler version is 13 or newer. > > Enabling this flag can improve performance through better loop analysis > > and auto-vectorization (SIMD) opportunities in modern GCC versions. > >=20 > > The explicit `-fno-tree-vectorize` flag was originally added in commit > > 973859f5230e (2009). A previous attempt to enable `-ftree-vectorize` > > was made in commit cb8646af24bd (2016), but it was reverted in > > fd6dbc53855f. The reason for the revert was that the inline x86 CABAC > > assembly code caused compiler errors ??? the compiler would run out of > > available registers during vectorization, making it unable to compile > > some functions. > >=20 > > In commit 182663a58a7a (2023), the problematic CABAC function was made > > non-inline. This significantly reduces the risk of register exhaustion > > caused by inlining large assembly blocks, making the vectorizer safer > > to enable for other functions. > >=20 > > Given improvements in GCC's vectorizer and the mitigation of the > > original issue, we now re-enable `-ftree-vectorize` for GCC version 13 > > and above. > >=20 > > Version log: > > Only allow GCC versions >=3D 13 to use -ftree-vectorize. > > Modify the commit description. > > Add historical context and rationale for the change. > >=20 > > Disscussion see: > > https://patchwork.ffmpeg.org/project/ffmpeg/patch/20250521061750.54882-= 1-jiawei@iscas.ac.cn/ > >=20 > >=20 > > Signed-off-by: Jiawei > > --- > > configure | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) >=20 > Thanks; I'm ok with this version. Whoever applies it can touch up the com= mit > message to remove the ???? word (maybe just replace it with an "as"), it > sounds reasonably right like that. the patch seems not to be on the mailing list I have v4 in my inbox but not v5, so if the patch is ok, maybe you are the only one who can apply it Maybe Jiawei is not subscribed to the ML so his mails would go to the moderation que (i didnt check) thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Dictatorship naturally arises out of democracy, and the most aggravated form of tyranny and slavery out of the most extreme liberty. -- Plato --dMK9NfDstrAqAuhj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEKAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCaE38ewAKCRBhHseHBAsP q9iPAJ9GplzilX+YBIPMO6KLbO5zra0F6wCeIQju+0R+4V5wBUJ+OstimwtH/wM= =B5+D -----END PGP SIGNATURE----- --dMK9NfDstrAqAuhj-- --===============0256631250563276479== 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". --===============0256631250563276479==--