From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15173 invoked by alias); 28 Dec 2013 16:28:16 -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 15140 invoked by uid 48); 28 Dec 2013 16:28:12 -0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/59615] "asm goto" output or at least clobbered operands Date: Sat, 28 Dec 2013 16:28:00 -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: unknown X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: jakub 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-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: 2013-12/txt/msg02304.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59615 --- Comment #4 from Jakub Jelinek --- But it would warn about it with -Wsign-compare. You want unsigned r = (unsigned) a + b; or similar to avoid undefined behavior if there is a possibility of signed integer overflow. Anyway, you definitely don't want to use inline asm in this case, if there is some code GCC doesn't optimize as good as you'd like to, just report that.