From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11682 invoked by alias); 10 Sep 2013 20:14:27 -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 11642 invoked by uid 48); 10 Sep 2013 20:14:22 -0000 From: "davidxl at google dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/58377] spurious "may be used uninitialized" warning with -Og Date: Tue, 10 Sep 2013 20:14:00 -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: 4.8.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: davidxl at google 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-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: 2013-09/txt/msg00765.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58377 --- Comment #8 from davidxl at google dot com --- (In reply to Neil Vachharajani from comment #7) > It seems like the whole problem is that the loop early exit goes through > bb_6 which is the same path the back-edge goes through. There is also one thing weird about the trunk GCC's IR Why is constant 0 propagated into the PHI node? _4 = PHI >>From the CFG, it should be like _4 = PHI ?