From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4865 invoked by alias); 19 Dec 2011 19:14:38 -0000 Received: (qmail 4851 invoked by uid 22791); 19 Dec 2011 19:14:37 -0000 X-SWARE-Spam-Status: No, hits=-2.9 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; Mon, 19 Dec 2011 19:14:25 +0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c Date: Mon, 19 Dec 2011 19:16:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P4 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.6.3 X-Bugzilla-Changed-Fields: Priority 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: 2011-12/txt/msg02154.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063 Jakub Jelinek changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P2 |P4 --- Comment #14 from Jakub Jelinek 2011-12-19 19:12:56 UTC --- Well, it is certainly desirable not to process the prologue insns during init_alias_analysis. The fact that stack pointer has the same value as frame pointer after the prologue is not usual and something the generic code isn't prepared for (usually either frame pointer is eliminated (of course then the register can be used for something else) or frame pointer is initialized from stack pointer and then decremented (or incremented) still inside of the prologue). So you need to tell the alias analysis about that, as the prologue isn't scanned, it is the backend responsibility to tell that.