From owner-freebsd-amd64@FreeBSD.ORG  Thu Dec 23 20:23:06 2004
Return-Path: <owner-freebsd-amd64@FreeBSD.ORG>
Delivered-To: freebsd-amd64@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 18DDA16A4CE
	for <amd64@freebsd.org>; Thu, 23 Dec 2004 20:23:06 +0000 (GMT)
Received: from mail4.speakeasy.net (mail4.speakeasy.net [216.254.0.204])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 7468B43D2D
	for <amd64@freebsd.org>; Thu, 23 Dec 2004 20:23:05 +0000 (GMT)
	(envelope-from jmg@hydrogen.funkthat.com)
Received: (qmail 32560 invoked from network); 23 Dec 2004 20:23:05 -0000
Received: from gate.funkthat.com (HELO hydrogen.funkthat.com) ([69.17.45.168])
          (envelope-sender <jmg@hydrogen.funkthat.com>)
          by mail4.speakeasy.net (qmail-ldap-1.03) with SMTP
          for <sean@mcneil.com>; 23 Dec 2004 20:23:04 -0000
Received: from hydrogen.funkthat.com (pcryty@localhost.funkthat.com
	[127.0.0.1])iBNKN3GH052669;	Thu, 23 Dec 2004 12:23:03 -0800 (PST)
	(envelope-from jmg@hydrogen.funkthat.com)
Received: (from jmg@localhost)
	by hydrogen.funkthat.com (8.12.10/8.12.10/Submit) id iBNKN2po052668;
	Thu, 23 Dec 2004 12:23:02 -0800 (PST)
Date: Thu, 23 Dec 2004 12:23:02 -0800
From: John-Mark Gurney <gurney_j@resnet.uoregon.edu>
To: Sean McNeil <sean@mcneil.com>
Message-ID: <20041223202302.GG19624@funkthat.com>
Mail-Followup-To: Sean McNeil <sean@mcneil.com>, amd64@freebsd.org
References: <1103830283.53421.3.camel@server.mcneil.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1103830283.53421.3.camel@server.mcneil.com>
User-Agent: Mutt/1.4.1i
X-Operating-System: FreeBSD 4.2-RELEASE i386
X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31  96 7A 22 B3 D8 56 36 F4
X-Files: The truth is out there
X-URL: http://resnet.uoregon.edu/~gurney_j/
X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html
cc: amd64@freebsd.org
Subject: Re: what is the proper asm spec for xchg
X-BeenThere: freebsd-amd64@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
Reply-To: John-Mark Gurney <gurney_j@resnet.uoregon.edu>
List-Id: Porting FreeBSD to the AMD64 platform <freebsd-amd64.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
	<mailto:freebsd-amd64-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-amd64>
List-Post: <mailto:freebsd-amd64@freebsd.org>
List-Help: <mailto:freebsd-amd64-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
	<mailto:freebsd-amd64-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 23 Dec 2004 20:23:06 -0000

Sean McNeil wrote this message on Thu, Dec 23, 2004 at 11:31 -0800:
> I'm looking at why audio/sdl_mixer will not compile and I see that
> devel/sdl12 has an include with
> 
> #elif defined(__GNUC__) && defined(__x86_64__)
> static __inline__ Uint16 SDL_Swap16(Uint16 x)
> {
>         __asm__("xchgb %b0,%h0" : "=q" (x) :  "0" (x));
>         return x;
> }
> 
> This appears to be incorrect as it is giving errors when compiled.  Does
> anyone more conversant with asm directives for amd64 have an idea what
> this should be?

well, from amd64/include/endian.h:
#define __byte_swap_word_var(x) \
__extension__ ({ register __uint16_t __X = (x); \
   __asm ("xchgb %h0, %b0" : "+Q" (__X)); \
   __X; })

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."