From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9612 invoked by alias); 16 Jun 2011 08:19:14 -0000 Received: (qmail 9601 invoked by uid 22791); 16 Jun 2011 08:19:10 -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 08:18:57 +0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/49419] [4.6/4.7 regression] gcc -O2 miscompiles gp2c 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: 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: 4.6.1 X-Bugzilla-Changed-Fields: Status Resolution 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 08:19:00 -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/msg01415.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49419 Jakub Jelinek changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED --- Comment #8 from Jakub Jelinek 2011-06-16 08:17:46 UTC --- The bug should be fixed now, though VRP should be cerrtainly improved in various ways, including choosing better vr during extract_range_from_assert, trying to derive numeric ranges from symbolic ranges x - 1 maximums or x + 1 minimums, and IMHO adjust_range_for_scev could use number_of_latch_executions to see if the number is simple enough and a smaller iteration count can be derived from its value ranges or, e.g. if it is the init SSA_NAME itself or that plus/minus a constant, it could determine it doesn't decrease until -INF but only until 0 +- constant.