From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765442AbXGWSmb (ORCPT ); Mon, 23 Jul 2007 14:42:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763259AbXGWSmX (ORCPT ); Mon, 23 Jul 2007 14:42:23 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56366 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760969AbXGWSmW (ORCPT ); Mon, 23 Jul 2007 14:42:22 -0400 Message-ID: <46A4F5EF.8010402@zytor.com> Date: Mon, 23 Jul 2007 11:39:43 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: Linus Torvalds CC: Satyam Sharma , Linux Kernel Mailing List , David Howells , Nick Piggin , Andi Kleen , Andrew Morton Subject: Re: [PATCH 2/8] i386: bitops: Rectify bogus "Ir" constraints References: <20070723160528.22137.84144.sendpatchset@cselinux1.cse.iitk.ac.in> <20070723160538.22137.35213.sendpatchset@cselinux1.cse.iitk.ac.in> In-Reply-To: X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > > On Mon, 23 Jul 2007, Satyam Sharma wrote: >> * The "I" constraint modifier is applicable only to immediate-value operands, >> and combining it with "r" is bogus. > > This is wrong too. > > The whole point of a "Ir" modifier is to say that the instruction takes > *either* an "I" or an "r". > > Andrew - the ones I've looked at were all wrong. Please don't take this > series. > Incidentally, I just noticed the x86-64 bitops have "dIr" as their constraint set. "d" would normally be redundant with "r", and as far as I know, gcc doesn't prefer one over the other without having "?" or "!" as part of the constraint, so is is "d" a stray or is there some meaning behind it? -hpa