From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19719 invoked by alias); 16 Jun 2011 20:09:03 -0000 Received: (qmail 19685 invoked by uid 22791); 16 Jun 2011 20:09:02 -0000 X-SWARE-Spam-Status: No, hits=-2.7 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 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; Thu, 16 Jun 2011 20:08:48 +0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/49444] IV-OPTs changes an unaligned loads into aligned loads incorrectly 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: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: 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 Date: Thu, 16 Jun 2011 20:09:00 -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 X-SW-Source: 2011-06/txt/msg01484.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49444 --- Comment #1 from Richard Guenther 2011-06-16 20:08:43 UTC --- Well, I'm 100% sure this is just the age-old bug that GCC can't expand misaligned indirect-refs (or nowadays mem-refs and target-mem-refs) on strict-align targets properly. Try the following on any GCC version: typedef int myint __attribute__((aligned(1))); int foo(myint *p) { return *p; } int main() { char c[5] = {}; return foo(&c[1]); } it'll fault on any strict-align target since forever. Now it would indeed be nice if _finally_ somebody would go and fix that ... Dup of ....