From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: MS-Windows tester wanted for trunk Date: Tue, 16 Sep 2014 19:03:22 +0300 Message-ID: <83a95z4kol.fsf@gnu.org> References: <5417F9B8.9020503@yandex.ru> <83r3zb4oyh.fsf@gnu.org> <54185B53.7030900@yandex.ru> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1410883435 780 80.91.229.3 (16 Sep 2014 16:03:55 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 16 Sep 2014 16:03:55 +0000 (UTC) Cc: emacs-devel@gnu.org To: Dmitry Antipov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Sep 16 18:03:47 2014 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 1XTvEG-0005jy-F1 for ged-emacs-devel@m.gmane.org; Tue, 16 Sep 2014 18:03:44 +0200 Original-Received: from localhost ([::1]:39006 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTvEF-0001Hx-Bf for ged-emacs-devel@m.gmane.org; Tue, 16 Sep 2014 12:03:43 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:50696) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTvE7-0001Hm-Sg for emacs-devel@gnu.org; Tue, 16 Sep 2014 12:03:41 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XTvE2-0001VQ-DZ for emacs-devel@gnu.org; Tue, 16 Sep 2014 12:03:35 -0400 Original-Received: from mtaout24.012.net.il ([80.179.55.180]:47817) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTvE2-0001Ts-55 for emacs-devel@gnu.org; Tue, 16 Sep 2014 12:03:30 -0400 Original-Received: from conversion-daemon.mtaout24.012.net.il by mtaout24.012.net.il (HyperSendmail v2007.08) id <0NC000J003X84K00@mtaout24.012.net.il> for emacs-devel@gnu.org; Tue, 16 Sep 2014 18:58:08 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout24.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0NC000CLT4CV6I90@mtaout24.012.net.il>; Tue, 16 Sep 2014 18:58:08 +0300 (IDT) In-reply-to: <54185B53.7030900@yandex.ru> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 80.179.55.180 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:174375 Archived-At: > Date: Tue, 16 Sep 2014 19:46:27 +0400 > From: Dmitry Antipov > CC: emacs-devel@gnu.org > > On 09/16/2014 06:31 PM, Eli Zaretskii wrote: > > > So, as suggested by that page, I marked the callback functions in > > w32font.c with '__attribute__((force_align_arg_pointer))', and then > > Emacs comes up normally. This attribute is available in GCC since > > v4.2. > > From GCC manual, as of 4.8: > > -mstackrealign > > Realign the stack at entry. That's the other solution suggested by the URL I cited. But it's too expensive: it adds the realignment overhead to _every_ function call. By contrast, the number of callback functions we have is quite small, and even if we decorate all of them with force_align_arg_pointer (which isn't strictly necessary, AFAIU, since most of them don't cons Lisp data), that's just a handful of functions that are not performance-critical. Is it possible to prevent this problem by using an intermediate local variable with a suitable alignment (sorry if this is a silly question, but I have only a very vague idea about alignment).