From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9235 invoked by alias); 22 Aug 2012 08:56:45 -0000 Received: (qmail 9220 invoked by uid 22791); 22 Aug 2012 08:56:43 -0000 X-SWARE-Spam-Status: No, hits=-4.3 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 22 Aug 2012 08:55:56 +0000 From: "steven at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/53676] [4.7 regression] empty loop is not always removed now Date: Wed, 22 Aug 2012 08:56:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: steven at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.2 X-Bugzilla-Changed-Fields: CC Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 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: 2012-08/txt/msg01522.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53676 Steven Bosscher changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |steven at gcc dot gnu.org --- Comment #14 from Steven Bosscher 2012-08-22 08:55:05 UTC --- (In reply to comment #13) > No, it's only the commit referenced in this PR. No optimization regressions > warrant a backport as they always come with the risk of regressing something > worse than performance. Trivial restoring of old behavior might be worth > backporting but the patch introduces a completely new non-trivial transform > into a core analysis engine that is shared among many passes. FWIW, it seems to me that small patches, even non-trivial ones, should be candidates for back-porting after they've been on the trunk or on a later release branch for a reasonable period of time. E.g. after 3 months on the GCC 4.8 trunk and with no resulting bugs reported, this patch should be considered for back-porting IMHO.