From mboxrd@z Thu Jan  1 00:00:00 1970
X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/9087
Path: news.gmane.org!not-for-mail
From: Alexander Monakov <amonakov@ispras.ru>
Newsgroups: gmane.linux.lib.musl.general
Subject: Re: atomic.h cleanup
Date: Sun, 10 Jan 2016 20:50:28 +0300 (MSK)
Message-ID: <alpine.LNX.2.20.1601102044510.32597@monopod.intra.ispras.ru>
References: <20160110122139.GF2016@debian> <20160110165718.GR238@brightrain.aerifal.cx> <20160110173509.GG2016@debian>
Reply-To: musl@lists.openwall.com
NNTP-Posting-Host: plane.gmane.org
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
X-Trace: ger.gmane.org 1452448243 23173 80.91.229.3 (10 Jan 2016 17:50:43 GMT)
X-Complaints-To: usenet@ger.gmane.org
NNTP-Posting-Date: Sun, 10 Jan 2016 17:50:43 +0000 (UTC)
To: musl@lists.openwall.com
Original-X-From: musl-return-9100-gllmg-musl=m.gmane.org@lists.openwall.com Sun Jan 10 18:50:43 2016
Return-path: <musl-return-9100-gllmg-musl=m.gmane.org@lists.openwall.com>
Envelope-to: gllmg-musl@m.gmane.org
Original-Received: from mother.openwall.net ([195.42.179.200])
	by plane.gmane.org with smtp (Exim 4.69)
	(envelope-from <musl-return-9100-gllmg-musl=m.gmane.org@lists.openwall.com>)
	id 1aIK8Y-0000Dv-1c
	for gllmg-musl@m.gmane.org; Sun, 10 Jan 2016 18:50:42 +0100
Original-Received: (qmail 32577 invoked by uid 550); 10 Jan 2016 17:50:40 -0000
Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm
Precedence: bulk
List-Post: <mailto:musl@lists.openwall.com>
List-Help: <mailto:musl-help@lists.openwall.com>
List-Unsubscribe: <mailto:musl-unsubscribe@lists.openwall.com>
List-Subscribe: <mailto:musl-subscribe@lists.openwall.com>
List-ID: <musl.lists.openwall.com>
Original-Received: (qmail 32556 invoked from network); 10 Jan 2016 17:50:39 -0000
In-Reply-To: <20160110173509.GG2016@debian>
User-Agent: Alpine 2.20 (LNX 67 2015-01-07)
Xref: news.gmane.org gmane.linux.lib.musl.general:9087
Archived-At: <http://permalink.gmane.org/gmane.linux.lib.musl.general/9087>

On Sun, 10 Jan 2016, Markus Wichmann wrote:
> | static inline int a_sc(volatile int* p, int x)
> | {
> |     __asm__ goto ("stwcx. %0, 0, %1\n\tbne- %l2" : : "r"(x), "r"(p) : "cc", "memory" : fail);
> |     return 1;
> | fail:
> |     return 0;
> | }
> 
> I tested the assembler output from both gcc and clang and it looks
> alright to me (testcase attached).

"asm goto" is an extension that appeared in gcc 4.5 and is not supported in
clang (I get "error: expected '(' after 'asm'" with clang 3.7).  I don't know
why you claim it works with clang.

Corresponding llvm bugs (no plans to add support soon):
https://llvm.org/bugs/show_bug.cgi?id=9295
https://llvm.org/bugs/show_bug.cgi?id=14406

Alexander