From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26743 invoked by alias); 10 Sep 2013 17:49:33 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 26715 invoked by uid 48); 10 Sep 2013 17:49:30 -0000 From: "rcopley at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/54412] Request for 32-byte stack alignment with -mavx on Windows Date: Tue, 10 Sep 2013 17:49:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 4.7.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: rcopley at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-09/txt/msg00750.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54412 --- Comment #4 from R Copley --- (In reply to Kai Tietz from comment #1) > MS' abi doesn't allow this. So I doubt we will be able to implement that > for this target. If we want to re-align stack on function-base we will run > into troubles with SEH-information. You might be right, I'm not sure. Are you aware that on 64-bit Windows, SEH is table-based, not frame-based (see, e.g., http://www.osronline.com/article.cfm?article=469)? > Doesn't it work to align explicit the variable itself? No (see attachments 2 and 3). If I understand correctly, the alignment specification is redundant anyway, because the variables are supposed to be naturally aligned, on their size. Assembling attachment 3 with "-g" and running it in gdb gives: Program received signal SIGSEGV, Segmentation fault. main () at bug1.s:46 46 vmovapd %ymm0, -96(%rbp) Thanks.