From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#63365: 30.0.50; GCC 13.1 breaks building Emacs with native-compilation Date: Sat, 24 Jun 2023 12:21:31 +0300 Message-ID: <83r0q1z04k.fsf@gnu.org> References: <86v8ffutg7.fsf@gnu.org> <838rca3frp.fsf@gnu.org> <86edm2jtih.fsf@gnu.org> <83jzvu1ijw.fsf@gnu.org> <87mt0pjk2w.fsf@aia00820.aia.gr> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="17908"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 63365@debbugs.gnu.org, arash@gnu.org, acorallo@gnu.org, svraka.andras@gmail.com, cyril.arnould@outlook.com To: Deus Max Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Jun 24 11:22:28 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1qCzTO-0004Hl-Kn for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 24 Jun 2023 11:22:26 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qCzT6-0008Ht-SU; Sat, 24 Jun 2023 05:22:08 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qCzT0-0008H9-E5 for bug-gnu-emacs@gnu.org; Sat, 24 Jun 2023 05:22:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qCzT0-0007zr-5r for bug-gnu-emacs@gnu.org; Sat, 24 Jun 2023 05:22:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1qCzSz-0007I6-Rs for bug-gnu-emacs@gnu.org; Sat, 24 Jun 2023 05:22:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 24 Jun 2023 09:22:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 63365 X-GNU-PR-Package: emacs Original-Received: via spool by 63365-submit@debbugs.gnu.org id=B63365.168759848627963 (code B ref 63365); Sat, 24 Jun 2023 09:22:01 +0000 Original-Received: (at 63365) by debbugs.gnu.org; 24 Jun 2023 09:21:26 +0000 Original-Received: from localhost ([127.0.0.1]:39930 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1qCzSQ-0007Gx-C0 for submit@debbugs.gnu.org; Sat, 24 Jun 2023 05:21:26 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:33710) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1qCzSM-0007Ge-O8 for 63365@debbugs.gnu.org; Sat, 24 Jun 2023 05:21:24 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qCzSH-0007tZ-7b; Sat, 24 Jun 2023 05:21:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=CYg2WWKXyBQMF9nMBUQfrwRHvwOtBBzhuD7TwBn5etg=; b=q4N4g5zUvh7g ieVp00sVBtfZJRj8FNq3dLYcFrP0fSaeeOeNPcy1cR2fAZ54YWdlYB+rcvC46KK3f3CbBANl9SdNh j6mnIdIMFAVfF8Vai+23bJMftTzZytdckPiVNehG+kiO4loelJVXubiyCGseGd2B5dTAo8jCHbaNc 6VFv8kphRej8oYr/Li7H/zaUOFU8IJ3l+/onrcryAML0kHTMHIXSrDbZcFKrXnvnBUKCkf0E83Uv2 /o0ja6HJpETVmBzWQFy6OFSJX58G4UIyfKeWSTGa9d1ux5iSEBv52rNEo+7VUgMiD6f59c3YRu5j+ P3IbHx2i39Dt12AZk13GAg==; Original-Received: from [87.69.77.57] (helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qCzSG-0000uB-DL; Sat, 24 Jun 2023 05:21:16 -0400 In-Reply-To: <87mt0pjk2w.fsf@aia00820.aia.gr> (message from Deus Max on Sat, 24 Jun 2023 12:17:11 +0300) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:263980 Archived-At: > From: Deus Max > Cc: Arash Esbati , 63365@debbugs.gnu.org, acorallo@gnu.org, > svraka.andras@gmail.com, cyril.arnould@outlook.com > Date: Sat, 24 Jun 2023 12:17:11 +0300 > > On 2023-06-23T15:15 Fri, Eli Zaretskii wrote: > > >> From: Arash Esbati > >> Cc: Andrea Corallo , cyril.arnould@outlook.com, > >> 63365@debbugs.gnu.org, svraka.andras@gmail.com > >> Date: Fri, 23 Jun 2023 13:41:10 +0200 > >> > >> > Also, why are you using -O3? That is not recommended when building > >> > Emacs. > >> > >> I wasn't aware of that. Can you elaborate why -O3 isn't recommended? > > > > In a nutshell, it bloats the code (due to excessive inlining), with no > > real effect on speed. The inner loops in Emacs are very large, and > > thus the techniques used by -O3 to speed up code (loop unrolling etc.) > > don't really work. Moreover, they could make things worse because the > > larger loops might no longer fit into the L1 cache of the CPU. > > > > The -O3 is well suited to speed up relatively simple algorithms with > > tight loops. Emacs has very few of those, in the places that matter > > for observable performance. > > Interesting. > This recommendation and the explanation are worth documenting somewhere. > Shouldn't a new bug be opened on documenting the GCC -O3 recommendation? I don't think it's our business to document this. The default build procedure correctly uses -O2. People who use non-default compilation switches should know what they are doing.