From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7912 invoked by alias); 6 Oct 2007 18:00:46 -0000 Received: (qmail 7887 invoked by uid 22791); 6 Oct 2007 18:00:44 -0000 X-Spam-Check-By: sourceware.org Received: from NaN.false.org (HELO nan.false.org) (208.75.86.248) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sat, 06 Oct 2007 18:00:40 +0000 Received: from nan.false.org (localhost [127.0.0.1]) by nan.false.org (Postfix) with ESMTP id 5439D980E0; Sat, 6 Oct 2007 18:00:38 +0000 (GMT) Received: from caradoc.them.org (22.svnf5.xdsl.nauticom.net [209.195.183.55]) by nan.false.org (Postfix) with ESMTP id 2EF9E98001; Sat, 6 Oct 2007 18:00:38 +0000 (GMT) Received: from drow by caradoc.them.org with local (Exim 4.67) (envelope-from ) id 1IeDx6-0004gj-Uq; Sat, 06 Oct 2007 14:00:36 -0400 Date: Sat, 06 Oct 2007 18:00:00 -0000 From: Daniel Jacobowitz To: Thiago Jung Bauermann Cc: gdb-patches@sourceware.org Subject: Re: [rfc] Use target descriptions for PowerPC Message-ID: <20071006180036.GB10179@caradoc.them.org> Mail-Followup-To: Thiago Jung Bauermann , gdb-patches@sourceware.org References: <20071005163754.GA26041@caradoc.them.org> <1191686484.18959.51.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1191686484.18959.51.camel@localhost.localdomain> User-Agent: Mutt/1.5.15 (2007-04-09) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2007-10/txt/msg00093.txt.bz2 On Sat, Oct 06, 2007 at 01:01:24PM -0300, Thiago Jung Bauermann wrote: > A few more comments, in the hope they can be useful. Thanks. > I see that the comments above about variants have been removed. Some of > them mention different processor models which also fit the register > description, and others describe choices made and restrictions with the > register descriptions. Is it worthwhile to transport these to the XML > files? In my opinion, not particularly. The comments mostly describe things which are no longer true. I just went through them again and added a couple back. > I'd suggest adding a description about what the FIXME above refers to. Not a thing. It should be removed. I had an #if 0 below there at one point, which is what needed to be fixed. Whoops! > > - /* FIXME: pgilliam/2005-10-21: Assume all PowerPC 64-bit linux systems > > - have altivec registers. If not, ptrace will fail the first time it's > > - called to access one and will not be called again. This wart will > > - be removed when Daniel Jacobowitz's proposal for autodetecting target > > - registers is implemented. */ > > The FIXME is being removed above. Was this issue fixed already? It seems > it's not, so maybe the FIXME could be moved to somewhere else, like > ppc-linux-nat.c where I believe the behaviour comes from? This patch fixes the problem. Actually, it's a little more complicated than that since the comment doesn't really describe the state of affairs. Take a look at how 32-bit PowerPC is handled; before my patch, I mean, not after. AltiVec registers are always included. It doesn't hurt, as long as the underlying target behaves gracefully: either fetching them or quietly not doing so. I made the 64-bit handling uniform with that. Ideally a target which doesn't supply the extra registers should report a description which doesn't include them. Any time someone wants to do that, it'd be easy to add the new description required. > BTW, both powerpc-32.xml and powerpc-64.xml include the altivec feature, > so you are assuming that ppc32 has altivec registers as well, right? No, I'm just preserving the messy status quo where we assume them present if we don't know. -- Daniel Jacobowitz CodeSourcery