From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14993 invoked by alias); 31 Jan 2013 10:26:34 -0000 Received: (qmail 14898 invoked by uid 48); 31 Jan 2013 10:26:13 -0000 From: "fweimer at redhat dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/55616] bogus warning about undefined overflow after overflow check Date: Thu, 31 Jan 2013 10:26:00 -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: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: fweimer at redhat dot com X-Bugzilla-Status: NEW 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 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: 2013-01/txt/msg02858.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55616 --- Comment #4 from Florian Weimer 2013-01-31 10:26:12 UTC --- (In reply to comment #3) > I don't see anything bogus on the warning, it is useful to inform the developer > about potentially unintended optimization removing some conditional. Neither programmer wrote (X + c) < X, this pattern does not occur in Okular nor Qt. I'm open to labeling the warning as "very difficult to diagnose" or "unhelpful" in these cases, and not "bogus". But I think it's a problem because it distracts from the real problems this warning intends to catch.