From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7454 invoked by alias); 7 Aug 2012 20:28:20 -0000 Received: (qmail 7443 invoked by uid 22791); 7 Aug 2012 20:28:19 -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; Tue, 07 Aug 2012 20:28:07 +0000 From: "aoliva at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/54114] [4.8 Regression] variable-tracking performance regression from 4.8-20120610 to 4.8-20120701 Date: Tue, 07 Aug 2012 20:28:00 -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: X-Bugzilla-Severity: normal X-Bugzilla-Who: aoliva at gcc dot gnu.org X-Bugzilla-Status: WAITING X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.8.0 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: 2012-08/txt/msg00405.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54114 --- Comment #4 from Alexandre Oliva 2012-08-07 20:28:05 UTC --- It seems quite clear to me that the new cost arises due to clobber_overlapping_mems, a relatively expensive operation that fixes a debug info correctness bug and that we just didn't do before. I'm afraid I can't think of a way to do it in a way that is significantly more efficient, so we'll have to choose between this additional cost, or living with debug locations that are no longer valid due to overlapping stores :-( I'm tempted to mark this as WONTFIX, but I thought I'd leave this open for a bit in case anyone else wants to give it a try.