From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8847 invoked by alias); 4 Mar 2010 21:27:19 -0000 Received: (qmail 8839 invoked by uid 22791); 4 Mar 2010 21:27:17 -0000 X-SWARE-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40 X-Spam-Check-By: sourceware.org Received: from mail-ww0-f41.google.com (HELO mail-ww0-f41.google.com) (74.125.82.41) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 04 Mar 2010 21:27:12 +0000 Received: by wwg30 with SMTP id 30so1064457wwg.0 for ; Thu, 04 Mar 2010 13:27:10 -0800 (PST) MIME-Version: 1.0 Received: by 10.216.90.130 with SMTP id e2mr24497wef.210.1267738030134; Thu, 04 Mar 2010 13:27:10 -0800 (PST) In-Reply-To: <20100304194645.GA20453@caradoc.them.org> References: <20100304180219.GA10826@intel.com> <20100304190934.GB15979@caradoc.them.org> <6dc9ffc81003041129i72a8a79bn66721fecc7b6a83b@mail.gmail.com> <20100304194645.GA20453@caradoc.them.org> Date: Thu, 04 Mar 2010 21:27:00 -0000 Message-ID: <6dc9ffc81003041327m379c6903g571f4d66aac8d61a@mail.gmail.com> Subject: Re: PATCH: 1/6: Add AVX support From: "H.J. Lu" To: "H.J. Lu" , GDB Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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: 2010-03/txt/msg00214.txt.bz2 On Thu, Mar 4, 2010 at 11:46 AM, Daniel Jacobowitz w= rote: > 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. =A0But 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. =A0Core debugging should still be > possible, and the newly added registers will be visible too. =A0If > that's not the case, fix GDB to function with the SSE registers > missing. Your description only works for truly NEW registers, which AVX registers aren't. AVX registers are actually the old SSE registers with different names. > The goal of the target description language is to communicate the > entire target to GDB. =A0If 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. =A0Also, it is not hard > to upgrade GDB on the host. =A0It can be hard to upgrade the target, of > course. > Gdb stub can only send XML target description with register names which gdb can pass to tdesc_numbered_register. If gdb doesn't know the new register names, it won't work. --=20 H.J.