From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4388 invoked by alias); 4 Mar 2010 19:47:01 -0000 Received: (qmail 4374 invoked by uid 22791); 4 Mar 2010 19:47:00 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 04 Mar 2010 19:46:53 +0000 Received: (qmail 8064 invoked from network); 4 Mar 2010 19:46:51 -0000 Received: from unknown (HELO caradoc.them.org) (dan@127.0.0.2) by mail.codesourcery.com with ESMTPA; 4 Mar 2010 19:46:51 -0000 Date: Thu, 04 Mar 2010 19:47:00 -0000 From: Daniel Jacobowitz To: "H.J. Lu" Cc: GDB Subject: Re: PATCH: 1/6: Add AVX support Message-ID: <20100304194645.GA20453@caradoc.them.org> Mail-Followup-To: "H.J. Lu" , GDB References: <20100304180219.GA10826@intel.com> <20100304190934.GB15979@caradoc.them.org> <6dc9ffc81003041129i72a8a79bn66721fecc7b6a83b@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6dc9ffc81003041129i72a8a79bn66721fecc7b6a83b@mail.gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) 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: 2010-03/txt/msg00209.txt.bz2 On Thu, Mar 04, 2010 at 11:29:38AM -0800, H.J. Lu wrote: > AVX registers aren't new registers, on top of SSE registers. AVX > registers are the super set of SSE registers. XMM0 is the alias > of the lower 128bit of YMM0. So we have either SSE target or > AVX target, depending on the processor/OS. We may have > remote gdb stub on an AVX processor/OS. But gdb, which > the stub is talking to, may not support AVX at all. If the stub > sends the AVX target description to gdb, gdb won't understand it > and will fail. No, it will fail to display SSE. Core debugging should still be possible, and the newly added registers will be visible too. If that's not the case, fix GDB to function with the SSE registers missing. The goal of the target description language is to communicate the entire target to GDB. If you're not putting enough in the description for an arbitrary XML-capable GDB to function, then you need to rethink how you've written the description. I do not think that having GDB negotiate with the target for an intermediate target description is a good idea. Also, it is not hard to upgrade GDB on the host. It can be hard to upgrade the target, of course. -- Daniel Jacobowitz CodeSourcery