From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2398 invoked by alias); 18 Jan 2015 18:06:26 -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 2355 invoked by uid 48); 18 Jan 2015 18:06:16 -0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/64655] Vectorizer is always using load aligned instructions with objects with the "aligned" attribute Date: Sun, 18 Jan 2015 18:06:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c X-Bugzilla-Version: 4.9.2 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: RESOLVED 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: bug_status resolution 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: 2015-01/txt/msg01736.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64655 Jakub Jelinek changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #6 from Jakub Jelinek --- You are wrong on this. You've told the compiler that those arrays will be aligned to 32 bytes, but they are not, so running the code is undefined behavior. malloc doesn't have a way to pass alignment requirements to it, so there is no way it could know about the alignment requirements of struct A.