From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3663 invoked by alias); 28 Jan 2010 13:53:20 -0000 Received: (qmail 3589 invoked by uid 48); 28 Jan 2010 13:53:04 -0000 Date: Thu, 28 Jan 2010 13:53:00 -0000 Message-ID: <20100128135304.3588.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug rtl-optimization/42889] [4.5 Regression] "-fcompare-debug failure (length)" with "-O1 -fgcse" In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "steven 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: 2010-01/txt/msg03221.txt.bz2 ------- Comment #10 from steven at gcc dot gnu dot org 2010-01-28 13:53 ------- The patch of comment #9 is a hack that doesn't solve anything. There are loads of other passes that may inadvertedly trigger a fast DCE if only a DEBUG_INSN is modified and needs to be rescanned. IMHO the only "proper" fix would be to teach DF not to run DCE (and any other DF-problem other than scan) if only DEBUG_INSNs are modified. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42889