From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29051 invoked by alias); 30 Dec 2009 16:59:29 -0000 Received: (qmail 28976 invoked by uid 48); 30 Dec 2009 16:59:18 -0000 Date: Wed, 30 Dec 2009 16:59:00 -0000 Message-ID: <20091230165918.28975.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug regression/42145] Incorrect "may be used uninitialized warning" for a very specific test case In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "manu at gcc dot gnu dot org" 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: 2009-12/txt/msg02804.txt.bz2 ------- Comment #3 from manu at gcc dot gnu dot org 2009-12-30 16:59 ------- This would need conditional PHIs, so a duplicate of PR20968. GCC never detects that ret is always initialized, it doesn't warn because at low optimization levels we do not warn for PHIs or because CCP (PR18501) just initializes the variable (probably to 1 or 10). There is some differences between the dumps of -O1 and -O2 in the way the logical or is transformed int bitwise-or and how dom1 deals with each of them, but I cannot tell if there is some missing optimization involved. *** This bug has been marked as a duplicate of 20968 *** -- manu at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |manu at gcc dot gnu dot org Status|UNCONFIRMED |RESOLVED Resolution| |DUPLICATE http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42145