From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1185 invoked by alias); 1 Feb 2013 12:22:38 -0000 Received: (qmail 1100 invoked by uid 48); 1 Feb 2013 12:22:07 -0000 From: "abel at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/55889] [4.8 Regression] ICE: in move_op_ascend, at sel-sched.c:6153 with -fschedule-insns -fselective-scheduling Date: Fri, 01 Feb 2013 12:22:00 -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: ice-on-valid-code X-Bugzilla-Severity: normal X-Bugzilla-Who: abel at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: abel 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: 2013-02/txt/msg00028.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55889 --- Comment #26 from Andrey Belevantsev 2013-02-01 12:22:05 UTC --- You are right, your suggestions is what I sketched in comment #21 as choices 1 or 2. Sorry for my unclear expalanation of what was actually happening. I don't have a problem with making sel-sched have extra checks when renaming registers before reload, which will make us notice a not obvious extra dependence and avoid renaming properly, as now we've figured out these dependences don't follow immediately from the RTL. I just want an extra opinion on whether such unexpected dependencies arising when a target (hard) register is replaced by a pseudo register should be normal within GCC, or do we attribute such dependencies only to the register pressure scheduling mode. FWIW, I would rather agree with the latter than with the former.