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.help Subject: Re: 64 bit official Windows builds Date: Fri, 12 Feb 2016 09:16:13 +0100 Message-ID: <87mvr6s5rm.fsf@wanadoo.es> 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> <834mde8j3x.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1455265014 25409 80.91.229.3 (12 Feb 2016 08:16:54 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 12 Feb 2016 08:16:54 +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 09:16:45 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 1aU8uD-00046y-3m for geh-help-gnu-emacs@m.gmane.org; Fri, 12 Feb 2016 09:16:45 +0100 Original-Received: from localhost ([::1]:58439 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU8u9-0005OT-1X for geh-help-gnu-emacs@m.gmane.org; Fri, 12 Feb 2016 03:16:41 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:37042) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU8tx-0005OH-H9 for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 03:16:30 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aU8tt-0007bl-Gd for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 03:16:29 -0500 Original-Received: from plane.gmane.org ([80.91.229.3]:46828) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU8tt-0007bA-8i for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 03:16:25 -0500 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1aU8tp-0003rK-NA for help-gnu-emacs@gnu.org; Fri, 12 Feb 2016 09:16:21 +0100 Original-Received: from 173.red-83-43-64.dynamicip.rima-tde.net ([83.43.64.173]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 12 Feb 2016 09:16:21 +0100 Original-Received: from ofv by 173.red-83-43-64.dynamicip.rima-tde.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 12 Feb 2016 09:16:21 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 68 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 173.red-83-43-64.dynamicip.rima-tde.net User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:LpBh7e3zX5eTHU7BwsUN0sKJawQ= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 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:109128 Archived-At: Eli Zaretskii writes: >> > 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. You missed the "also". The compiler version can have a dramatic impact on some cases (it is quite common to find 10x differences on some microbenchmarks) but I'm more prone to point fingers to what is around of the compiler, something that I hinted on my previous message. >> 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. Okay, let's scratch that hypothesis then. >> 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. Maybe I'll try the comparision, but at the moment I only have virtual machines with Windows 64 bits and those are not specially reliable for performance measurements, although a 2x difference on real metal should have some impact on the VM too. >> 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. Are there reports about Dired being slow on Windows 32 bits? Just curious. > 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. I'm glad you think this way. So now we have agreed that the existence of a dramatic performance gap between 32 and 64 bits Emacs executables and its cause being API thunking is just a theory of yours based on limited evidence :-) My also (limited) evidence is that 64 bit Windows binaries can be a bit faster than 32 bit ones, and vice-versa. For instance: my experience building complex C++ code with GCC is that the 32 bit compiler runs a bit faster than its 64 bit version. For Emacs, I see no difference, it is responsive on both systems.