From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 57875 invoked by alias); 17 Oct 2015 12:52:56 -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 57804 invoked by uid 48); 17 Oct 2015 12:52:52 -0000 From: "ch3root at openwall dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/67999] Wrong optimization of pointer comparisons Date: Sat, 17 Oct 2015 12:52:00 -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: 5.2.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ch3root at openwall dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: 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: 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: 2015-10/txt/msg01372.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67999 --- Comment #4 from Alexander Cherepanov --- Interesting. In particular, this means that the warning "Argument 'size' of function malloc has a fishy (possibly negative) value" from valgrind is a serious thing. Is this gcc limitation documented somewhere? Is there a better reference than this bug? Am I right that the C standards do not allow for such a limitation (and hence this should not be reported to glibc as a bug) and gcc is not standards-compliant in this regard? Or I'm missing something?