From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings via "Emacs development discussions." Newsgroups: gmane.emacs.devel Subject: Re: The Emacs master is much slower than the emacs-27 branch. Date: Sat, 05 Dec 2020 08:14:24 +0000 Message-ID: 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> Reply-To: Gregory Heytings Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40113"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Alpine 2.22 (NEB 394 2020-01-19) Cc: acm@muc.de, stephen.berman@gmx.net, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Dec 05 09:15:21 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 1klSiu-000AKM-O5 for ged-emacs-devel@m.gmane-mx.org; Sat, 05 Dec 2020 09:15:20 +0100 Original-Received: from localhost ([::1]:43390 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1klSit-0006Oe-PU for ged-emacs-devel@m.gmane-mx.org; Sat, 05 Dec 2020 03:15:19 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52844) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klSiG-0005xY-91 for emacs-devel@gnu.org; Sat, 05 Dec 2020 03:14:40 -0500 Original-Received: from mx.sdf.org ([205.166.94.24]:53480) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klSiE-0006Xa-Fx; Sat, 05 Dec 2020 03:14:40 -0500 Original-Received: from sdf.org (IDENT:ghe@faeroes.freeshell.org [205.166.94.9]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 0B58EQWw022064 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Sat, 5 Dec 2020 08:14:26 GMT Original-Received: (from ghe@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 0B58F2sl004724; Sat, 5 Dec 2020 08:15:02 GMT In-Reply-To: <83tut0d7e9.fsf@gnu.org> Received-SPF: pass client-ip=205.166.94.24; envelope-from=ghe@sdf.org; helo=mx.sdf.org X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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:260341 Archived-At: >> Sorry, I meant: it only improves compilation with -Og _and -O0_. I >> don't know if -O0 is important. > > Given my measurements (see upthread), the effect on -O0 build is > negligible. And yes, -O0 _is_ important. > 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