From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12415 invoked by alias); 29 Feb 2012 22:19:18 -0000 Received: (qmail 12405 invoked by uid 22791); 29 Feb 2012 22:19:17 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_FC 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, 29 Feb 2012 22:19:05 +0000 From: "wschmidt at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/52424] dom prematurely pops entries from const_and_copies stack Date: Wed, 29 Feb 2012 23:18:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: wschmidt at gcc dot gnu.org X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: wschmidt at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: 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: 2012-02/txt/msg02874.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52424 --- Comment #9 from William J. Schmidt 2012-02-29 22:19:03 UTC --- (In reply to comment #8) > I think this is related to PR 45685. On the surface this looked like a good possibility. However, I just tried compiling the code from that PR on powerpc64 with this patch applied (-O3 -S -mcpu=power7 -misel) and summation_helper_1 is still generating an extra branch while summation_helper_2 produces a conditional move. The only difference in the tree-optimized dumps between the two involve cond_exprs whose operands appear in reverse order, and some of the -1's are (unsigned)(-1) instead (i.e., 4294967295). This appears to be enough for ifcvt to miss the opportunity.