From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: =?utf-8?Q?=C3=93scar_Fuentes?= Newsgroups: gmane.emacs.devel Subject: Re: The Emacs master is much slower than the emacs-27 branch. Date: Sat, 05 Dec 2020 15:47:32 +0100 Message-ID: <87wnxwwbqz.fsf@telefonica.net> References: <877dpyzg9d.fsf@rub.de> <87czzpsyqn.fsf@gmx.net> <83o8j9eqwx.fsf@gnu.org> <874kl1spe9.fsf@gmx.net> <83blf9em55.fsf@gnu.org> <87zh2tr82r.fsf@gmx.net> <87v9dhr7i5.fsf@gmx.net> <838sadefiw.fsf@gnu.org> <83360le421.fsf@gnu.org> <83y2idcn8q.fsf@gnu.org> <83wnxxcmjr.fsf@gnu.org> <83tut0d7e9.fsf@gnu.org> <8c5fe90c-72ca-a2c3-29d2-1849458bb85a@gmx.at> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39791"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: emacs-devel@gnu.org Cancel-Lock: sha1:anX3nj9M6VnYV3U/zix9tHFw6SM= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Dec 05 15:49:04 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1klYrw-000AG8-BD for ged-emacs-devel@m.gmane-mx.org; Sat, 05 Dec 2020 15:49:04 +0100 Original-Received: from localhost ([::1]:51656 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1klYrv-0000uQ-CG for ged-emacs-devel@m.gmane-mx.org; Sat, 05 Dec 2020 09:49:03 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:55926) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klYqe-00008I-Ov for emacs-devel@gnu.org; Sat, 05 Dec 2020 09:47:45 -0500 Original-Received: from static.214.254.202.116.clients.your-server.de ([116.202.254.214]:49582 helo=ciao.gmane.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klYqa-0003al-Mh for emacs-devel@gnu.org; Sat, 05 Dec 2020 09:47:44 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1klYqX-0008ii-N2 for emacs-devel@gnu.org; Sat, 05 Dec 2020 15:47:37 +0100 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:260363 Archived-At: martin rudalics writes: >> I don't know what happens on your computer (what is your >> platform/compiler?) but on mine (Debian GNU/Linux with the latest >> Linux kernel and the latest GCC) the effect on -O0 is almost the >> same as on -Og for this particular benchmark. I just tried again on >> the emacs-27 branch: >> >> -Og: ~67s >> -O0: ~63s >> -O1: ~26s >> -O2: ~18s >> -O3: ~17s > > So when I want to compare Emacs 27 and Emacs 28 benchmarks, -Og builds > are off limits. Now can I use O0 builds or do I have to use O1-O3 > builds exclusively? -Og is the recommended setting for the edit/build/debug cycle [1], because it *improves* debug info accuracy over -O0 *and* also runs faster, which is a significant bonus. So IMHO it is a good thing to not regress -Og too much. -O0, on the other hand, shouldn't be a concern. 1. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html