From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-365865-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 26247 invoked by alias); 19 Aug 2011 06:54:03 -0000
Received: (qmail 26238 invoked by uid 22791); 19 Aug 2011 06:54:02 -0000
X-SWARE-Spam-Status: No, hits=-2.6 required=5.0	tests=ALL_TRUSTED,AWL,BAYES_00,SARE_SUB_6CONS_WORD,TW_CX,TW_PX
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, 19 Aug 2011 06:53:47 +0000
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/50123] cmpxchg generated for atomic and with zero/or with -1
Date: Fri, 19 Aug 2011 07:29:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Changed-Fields: CC
Message-ID: <bug-50123-4-LLZxVsMb6q@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-50123-4@http.gcc.gnu.org/bugzilla/>
References: <bug-50123-4@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: 2011-08/txt/msg01639.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50123

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aldyh at gcc dot gnu.org,
                   |                            |amacleod at redhat dot com,
                   |                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-08-19 06:53:18 UTC ---
While we could do this on i?86/x86_64 now, it sounds better to do it in the
generic code (folding or expansion), but for that we need to wait for the
extended sync builtins that are currently brewing on cxx-mem-model branch
(because __sync_fetch_and_{and,or} are full barriers, while __sync_test_and_set
is not).