From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: 64 bit official Windows builds Date: Fri, 12 Feb 2016 09:48:18 +0200 Message-ID: <834mde8j3x.fsf@gnu.org> References: <2577057e-98d3-41ce-ade2-1496648b09c3@googlegroups.com> <8337t3qdpd.fsf@gnu.org> <83wpqb7yzk.fsf@gnu.org> <8760xuuc3g.fsf@wanadoo.es> <83h9he8lkp.fsf@gnu.org> <87vb5us8iy.fsf@wanadoo.es> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1455263336 31264 80.91.229.3 (12 Feb 2016 07:48:56 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 12 Feb 2016 07:48:56 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Feb 12 08:48:56 2016 Return-path: Envelope-to: geh-help-gnu-emacs@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 1aU8TD-00087D-F5 for geh-help-gnu-emacs@m.gmane.org; Fri, 12 Feb 2016 08:48:51 +0100 Original-Received: from localhost ([::1]:58284 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU8TC-0008Cz-Lq for geh-help-gnu-emacs@m.gmane.org; Fri, 12 Feb 2016 02:48:50 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:58343) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU8T1-0008CM-Gs for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 02:48:40 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aU8Sy-00014V-9g for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 02:48:39 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:42827) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU8Sy-00014R-6f for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 02:48:36 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:1824 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1aU8Sw-0006WK-Vg for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 02:48:35 -0500 In-reply-to: <87vb5us8iy.fsf@wanadoo.es> (message from =?iso-8859-1?Q?=D3s?= =?iso-8859-1?Q?car?= Fuentes on Fri, 12 Feb 2016 08:16:37 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:109127 Archived-At: > From: Óscar Fuentes > Date: Fri, 12 Feb 2016 08:16:37 +0100 > > Eli Zaretskii writes: > > >> > That thunking is the culprit is my theory, not a fact; however, I > >> > cannot find any other explanation. If someone does, I'm all ears. > >> > >> I mentioned some possibilities on a previous message. Did you use the > >> same toolset and libraries for the 32 and 64 bits build? > > > > No. The program was compiled by mingw.org's MinGW for 32 bits and by > > MinGW64 for 64 bits. > > There you have a strong candidate for explaining the difference. That > probably also means that they were different compiler versions. I find it hard to believe that compiler version differences can explain a factor of two. It contradicts every bit of my experience with GCC over the last 30 years. > >> The MinGW and MinGW-w64 (32/64 bits) runtimes diverged quite a bit. > > > > GNU Find uses only msvcrt.dll, no other runtime libraries are involved > > in any significant way. > > As you know, there are other code pieces that are linked into the > executable besides the C runtime (which MinGW(-w64) supersede by > providing their implementations for certain functions, plus other > features missing from msvcrt.dll). IIRC some *stat functions are very > slow on Mingw, maybe the MinGW-w64 guys introduced improvements, just a > guess. Not according to the current MinGW64's Git repository. They basically simply call the msvcrt _stat. And I doubt such a speedup is really possible at all, given the simplistic implementation of 'stat' in msvcrt -- you cannot do less, really. > Why don't you build both 32 and 64 bits executables of GNU Find with > MinGW-w64 (same toolset version) for comparing its performance? Sorry, I don't have time for that. But anyone who is interested can do this experiment, the sources (and the binaries) are on the ezwinports site. FWIW, I'd be very glad to hear that my measurements were some fluke and should be disregarded. > Not saying that GNU Find will be representative of what you can expect > from Emacs. (GNU Find: I/O bound; Emacs: user bound.) Performance only matters when you do prolonged operations. One such prolonged operation in Emacs is reading a directory in Dired, in which case what Emacs does is quite similar to what Find does. For someone who uses Dired extensively, the GNU Find example is not irrelevant. Memory- and CPU-intensive operations is another matter. But here, too, I'd welcome actual measurements more than theories. Measurements can and do surprise, as is known to anyone who ever profiled a real-life program.