From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-417598-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 23471 invoked by alias); 13 Mar 2013 13:50:00 -0000
Received: (qmail 23262 invoked by uid 48); 13 Mar 2013 13:49:12 -0000
From: "andi-gcc at firstfloor dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/55947] non constant memory models lose HLE qualifiers
Date: Wed, 13 Mar 2013 13:50:00 -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: andi-gcc at firstfloor dot 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:
Message-ID: <bug-55947-4-ifZjFlDnHG@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-55947-4@http.gcc.gnu.org/bugzilla/>
References: <bug-55947-4@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: 2013-03/txt/msg01040.txt.bz2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55947

--- Comment #3 from Andi Kleen <andi-gcc at firstfloor dot org> 2013-03-13 13:49:10 UTC ---
It was pointed out to me that atomic triggers this with, when compiled with no
optimization. For HLE wrong hints would be generated.


bool test_and_set(memory_order __m = memory_order_seq_cst) noexcept
{

      return __atomic_test_and_set (&_M_i, __m);

}

bool foo(std::atomic_flag fl) {

    return fl.test_and_set(std::memory_order_relaxed);

}