From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-381361-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 24409 invoked by alias); 26 Jan 2012 13:03:26 -0000
Received: (qmail 24399 invoked by uid 22791); 26 Jan 2012 13:03:25 -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; Thu, 26 Jan 2012 13:03:13 +0000
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/51798] [4.7 regression] libstdc++ atomicity performance regression due to __sync_fetch_and_add
Date: Thu, 26 Jan 2012 13:52:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Priority: P1
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 4.7.0
X-Bugzilla-Changed-Fields:
Message-ID: <bug-51798-4-dxzAex0DM5@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-51798-4@http.gcc.gnu.org/bugzilla/>
References: <bug-51798-4@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: 2012-01/txt/msg03036.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51798

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-26 13:01:58 UTC ---
What about the other files that use __sync_* in libstdc++?
include/tr1/shared_ptr.h, include/bits/shared_ptr_base.h,
include/profile/impl/profiler_state.h, libsupc++/guard.cc and parts of
include/parallel/compatibility.h use __sync_*compare_and_swap or
__sync_lock_test_and_set, so I assume that we have the same code for those on
ppc* as before, but in
include/parallel/compatibility.h, libsupc++/eh_tm.cc, libsupc++/eh_ptr.cc and
libsupc++/eh_throw.cc __sync_*fetch* is used.  Should we change all those to
use acq_rel semantics __atomic* counterparts in addition to
include/ext/atomicity.h and config/cpu/generic/atomicity_builtins/atomicity.h?