From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:50614)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <rth7680@gmail.com>) id 1aodzz-0002AK-Qt
	for qemu-devel@nongnu.org; Fri, 08 Apr 2016 17:31:28 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <rth7680@gmail.com>) id 1aodzv-0007R0-Nr
	for qemu-devel@nongnu.org; Fri, 08 Apr 2016 17:31:27 -0400
Received: from mail-qk0-x241.google.com ([2607:f8b0:400d:c09::241]:35926)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <rth7680@gmail.com>) id 1aodzv-0007Qv-KS
	for qemu-devel@nongnu.org; Fri, 08 Apr 2016 17:31:23 -0400
Received: by mail-qk0-x241.google.com with SMTP id e124so5581929qkc.3
	for <qemu-devel@nongnu.org>; Fri, 08 Apr 2016 14:31:22 -0700 (PDT)
Sender: Richard Henderson <rth7680@gmail.com>
References: <1460050358-25025-1-git-send-email-cota@braap.org>
	<1460050358-25025-7-git-send-email-cota@braap.org>
	<87bn5kb6ek.fsf@linaro.org> <5707FA93.9090803@twiddle.net>
	<87a8l3bxpc.fsf@linaro.org> <570821FD.2010107@redhat.com>
From: Richard Henderson <rth@twiddle.net>
Message-ID: <57082326.4050604@twiddle.net>
Date: Fri, 8 Apr 2016 14:31:18 -0700
MIME-Version: 1.0
In-Reply-To: <570821FD.2010107@redhat.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Subject: Re: [Qemu-devel] [PATCH v2 06/13] qemu-thread: add simple
 test-and-set spinlock
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>
Cc: "Emilio G. Cota" <cota@braap.org>, QEMU Developers <qemu-devel@nongnu.org>, MTTCG Devel <mttcg@greensocs.com>, Peter Crosthwaite <crosthwaite.peter@gmail.com>, Peter Maydell <peter.maydell@linaro.org>, Sergey Fedorov <serge.fdrv@gmail.com>

On 04/08/2016 02:26 PM, Paolo Bonzini wrote:
> 
> 
> On 08/04/2016 23:24, Alex Bennée wrote:
>>> Except that quite a lot of hosts can only (efficiently) do atomic operations on
>>> a minimum of 4 byte quantities.  I'd rather continue to use int here.
>>
>> I suspect bool == unsigned int underneath. But having true/false and 0/1 mixed up
>> gets confusing even if they are equivalent.
> 
> Sometimes sizeof(bool) == 1.

sizeof(bool) == 1 everywhere except MacOSX, where it's 4.


r~