From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-339332-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 26812 invoked by alias); 3 Dec 2010 15:27:23 -0000
Received: (qmail 26801 invoked by uid 22791); 3 Dec 2010 15:27:23 -0000
X-SWARE-Spam-Status: No, hits=-2.8 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; Fri, 03 Dec 2010 15:27:18 +0000
From: "amonakov at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/46758] [4.5/4.6 Regression] -fgraphite-identity produces wrong code when using 64bit constants
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: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: amonakov 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: 4.5.2
X-Bugzilla-Changed-Fields: Status Last reconfirmed CC Ever Confirmed
Message-ID: <bug-46758-4-pufgQlm4Yg@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-46758-4@http.gcc.gnu.org/bugzilla/>
References: <bug-46758-4@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
Date: Fri, 03 Dec 2010 15:27:00 -0000
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: 2010-12/txt/msg00315.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46758

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.12.03 15:27:13
                 CC|                            |amonakov at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #1 from Alexander Monakov <amonakov at gcc dot gnu.org> 2010-12-03 15:27:13 UTC ---
In this particular example, the problem is in scan_tree_for_params_int:

  int v = int_cst_value (cst);

  mpz_init (val);
  mpz_set_si (val, 0);

  /* Necessary to not get "-1 = 2^n - 1". */
  if (v < 0)
    mpz_sub_ui (val, val, -v);
  else
    mpz_add_ui (val, val, v);

(gdb) p cst
$8 = (tree) 0x7ffff5a4e848
(gdb) pt
 <integer_cst 0x7ffff5a4e848 type <integer_type 0x7ffff7ed0738 long long int>
constant -8589934593>
(gdb) p v
$9 = -1
(gdb) 

There are multiple places where graphite uses int_cst_value.  Note that the
problem may be more severe on 32-bit hosts as there the tree may hold a 64-bit
constant but mpz_*_{u,s}i accepts 'long's.