From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-376934-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 2849 invoked by alias); 14 Dec 2011 12:51:22 -0000
Received: (qmail 2836 invoked by uid 22791); 14 Dec 2011 12:51:21 -0000
X-SWARE-Spam-Status: No, hits=-2.9 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; Wed, 14 Dec 2011 12:51:08 +0000
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug lto/51497] [4.7 Regression] The run time for the polyhedron test nf.f90 is ~10% slower with -flto after revision 182107
Date: Wed, 14 Dec 2011 13:06:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: lto
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth 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: 4.7.0
X-Bugzilla-Changed-Fields: Status AssignedTo
Message-ID: <bug-51497-4-4EiFKxJDcj@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-51497-4@http.gcc.gnu.org/bugzilla/>
References: <bug-51497-4@http.gcc.gnu.org/bugzilla/>
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: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
X-SW-Source: 2011-12/txt/msg01500.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51497

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-12-14 12:50:52 UTC ---
Created attachment 26080
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26080
patch candidate

Ok, so the reason is that we now stream the VLA types for, for example 'x',
locally.  Thus they do not go through the type merging machinery (no
problem) - but they also do not get a TYPE_CANONICAL computed, which would
not be bad either would it be itself, but it is NULL_TREE and thus
references to such VLA arrays get alias-set zero.

The function local LTO sections are not structured in a way we can
arrange to call uniquify_nodes, but we should be able to fixup
canonical types (and variant types).