From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9912 invoked by alias); 9 Apr 2012 23:54:33 -0000 Received: (qmail 9904 invoked by uid 22791); 9 Apr 2012 23:54:32 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,HK_NAME_MR_MRS,KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 09 Apr 2012 23:54:16 +0000 From: "mrs at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/52571] vectorizer changes alignment of common symbols Date: Mon, 09 Apr 2012 23:54:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: mrs at gcc dot gnu.org X-Bugzilla-Status: REOPENED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: CC Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 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 X-SW-Source: 2012-04/txt/msg00579.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52571 mrs@gcc.gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mrs at gcc dot gnu.org --- Comment #11 from mrs at gcc dot gnu.org 2012-04-09 23:52:54 UTC --- Ah, I had another thought. COMDAT and LINKONCE things I don't think can be realigned for all the same reasons that one cannot align COMMON. I've not thought about this long and hard, so, could be wrong, so, would be good to have a C++ or a vectorizer person review the idea. The idea is, if you compile one translation unit with a vectorizor on, and another with it off, we wind up with two instantiations, each with different alignment, and the one picked at the end need not be either of them, but rather an explicit instantiation. This seems identical to what happens to common to me.