From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25092 invoked by alias); 5 Jul 2011 18:10:41 -0000 Received: (qmail 25079 invoked by uid 22791); 5 Jul 2011 18:10:41 -0000 X-SWARE-Spam-Status: No, hits=-2.7 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 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, 05 Jul 2011 18:10:25 +0000 From: "jason at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/49519] [4.7 Regression] Revision 175272 miscompiled 447.dealII in SPEC CPU 2006 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jason at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.0 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 Date: Tue, 05 Jul 2011 18:10:00 -0000 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: 2011-07/txt/msg00348.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49519 Jason Merrill changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu.org --- Comment #11 from Jason Merrill 2011-07-05 18:10:24 UTC --- (In reply to comment #7) > Expanding arguments in different ways occurs because corresponding GIMPLE > statements are of different types. > For 'good' case we have expression of type > COMPONENT_REF > > While for 'bad' one it is just a > MEM_REF > > For that different kinds we have slightly different expanding. > > The different expression types comes from front-end, at least in einline phase > accesses are different: The front end doesn't create MEM_REFs, they are all produced in the middle end. If tail call optimizations have trouble with them, that sounds like the bug. I'm unable to reproduce your work; when I compile step-14.cc I never hit mem_overlaps_already_clobbered_arg_p while compiling do_call. And reverting my change to tsubst_arg_types doesn't affect the use of MEM_REF in do_call. What optimization options are you using? I'm using -O -fipa-sra -foptimize-sibling-calls, as mentioned.