From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: =?utf-8?Q?=C3=93scar_Fuentes?= Newsgroups: gmane.emacs.devel Subject: Re: Default compiler optimization level for building dev sources Date: Fri, 22 Apr 2016 17:00:38 +0200 Message-ID: <87h9etvgbt.fsf@wanadoo.es> References: <87lh45vib7.fsf@wanadoo.es> <8360v9671f.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1461337275 27527 80.91.229.3 (22 Apr 2016 15:01:15 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 22 Apr 2016 15:01:15 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Apr 22 17:01:06 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1atcZt-0003U0-Vm for ged-emacs-devel@m.gmane.org; Fri, 22 Apr 2016 17:01:06 +0200 Original-Received: from localhost ([::1]:34553 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atcZt-0004yi-Fi for ged-emacs-devel@m.gmane.org; Fri, 22 Apr 2016 11:01:05 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:59222) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atcZk-0004nA-35 for emacs-devel@gnu.org; Fri, 22 Apr 2016 11:01:01 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1atcZg-0006Kg-1y for emacs-devel@gnu.org; Fri, 22 Apr 2016 11:00:56 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:52629) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atcZe-0006KO-SK for emacs-devel@gnu.org; Fri, 22 Apr 2016 11:00:51 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1atcZa-0003Fn-34 for emacs-devel@gnu.org; Fri, 22 Apr 2016 17:00:46 +0200 Original-Received: from 120.red-88-22-75.staticip.rima-tde.net ([88.22.75.120]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 22 Apr 2016 17:00:46 +0200 Original-Received: from ofv by 120.red-88-22-75.staticip.rima-tde.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 22 Apr 2016 17:00:46 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 42 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 120.red-88-22-75.staticip.rima-tde.net User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.92 (gnu/linux) Cancel-Lock: sha1:saROHRlK0PTGzCAYxJXrinC1VnU= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:203179 Archived-At: Eli Zaretskii writes: >> I'm using Emacs 25.0.92 on Windows and it seems remarkably slower than >> the previous binary. This one was built with a plain config && make >> while the previous one had CFLAGS set to -O3 and other extra >> optimization flags. > > So you are saying that -O2 (that's the default) is significantly > slower than -O3? No, I'm saying that this binary feels quite slower than the previous one. > That's strange, my experience is that -O3 is > generally not faster than -O2 and sometimes slower. No arguing here. The cause must be elsewhere. The previous binary was one year old and the current one is from a few days old master but I doubt that such performance deterioration was caused by the introduced changes with nobody noticing until now. I need to investigate further. >> Maybe the build does not turn on optimizations when it detects that the >> sources are on a repo. Sorry for asking here instead of checking it >> myself but today I have no access to the sources nor the web. > > I don't think so. The default is -O2, so if you want -O3, you need to > request it by saying "CFLAGS='-O3' ./configure ...". > > Do you still have the source directory tree where you b uilt the > previous binary? If so, please tell what configure-time switches you > used and which compiler switches do you see in src/Makefile. I *think* that the build dir is still around, but I have no access to that VM for now. I trust you on the default CFLAGS, but maybe makepkg-mingw (this is the MSYS2 way of building packages) did something on its own. I'll check the Makefile and re-launch the build with some flag for showing the compile command instead of just `CC foo.c' (I guess that `make VERBOSE=1' will do.) Thank you.