From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16732 invoked by alias); 21 May 2003 19:45:12 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 16716 invoked from network); 21 May 2003 19:45:12 -0000 Received: from unknown (HELO mx1.redhat.com) (66.187.233.31) by sources.redhat.com with SMTP; 21 May 2003 19:45:12 -0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.11.6/8.11.6) with ESMTP id h4LJjBH03137 for ; Wed, 21 May 2003 15:45:11 -0400 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [172.16.52.156]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id h4LJjAI11377; Wed, 21 May 2003 15:45:10 -0400 Received: from localhost.localdomain (vpn50-3.rdu.redhat.com [172.16.50.3]) by pobox.corp.redhat.com (8.11.6/8.11.6) with ESMTP id h4LJj9o04662; Wed, 21 May 2003 15:45:09 -0400 Received: (from kev@localhost) by localhost.localdomain (8.11.6/8.11.6) id h4LJj4r32183; Wed, 21 May 2003 12:45:04 -0700 Date: Wed, 21 May 2003 19:45:00 -0000 From: Kevin Buettner Message-Id: <1030521194503.ZM32182@localhost.localdomain> In-Reply-To: Andrew Cagney "Re: [WIP/RFC] MIPS registers overhaul" (May 21, 3:15pm) References: <1030517004052.ZM13153@localhost.localdomain> <3ECA9587.4090407@redhat.com> <3ECB9C8F.1060706@redhat.com> <20030521154134.GA7667@nevyn.them.org> <3ECBA393.9020904@redhat.com> <20030521165816.GA8784@nevyn.them.org> <1030521183234.ZM31903@localhost.localdomain> <3ECBD034.3080504@redhat.com> To: Andrew Cagney , Kevin Buettner Subject: Re: [WIP/RFC] MIPS registers overhaul Cc: Daniel Jacobowitz , cgd@broadcom.com, gdb-patches@sources.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2003-05/txt/msg00397.txt.bz2 On May 21, 3:15pm, Andrew Cagney wrote: > > On May 21, 12:58pm, Daniel Jacobowitz wrote: > > > >> > From GDB's view point, the ISA is 64 bit. > >> > > >> > The fact that a specific remote debug agent choses to use 32 bit > >> > registers is a limitation of that debug agent / kernel. An embedded > >> > target, and I'm pretty sure IRIX 6.5, for instance, don't do that. > > > >> > >> No, from GDB's view point in this situation, the target ISA is _NOT_ 64 > >> bit. Nothing 64-bit is available, either to the inferior or to the > >> debugger. Period. > >> > >> I would be a little surprised if IRIX didn't work that way too, but I > >> don't have access to IRIX to poke around. > > > > > > I too would be surprised. I should think that SGI would want to > > ensure that legacy programs (i.e, those using the o32 ABI) behave the > > same when run on 64-bit hardware as they do when run on 32-bit > > hardware. One of the implications of this is that illegal > > instructions in the 32-bit ISA should continue to be illegal when run > > on the 64-bit hardware. > > Er, it's the same deal as for SPARC. If GDB is built against the 64 bit > debug interface, it can debug both 32 and 64 bit applications. This is > the debuggers view, not the program being run's view. Well, sure. But for such applications, you don't lose anything by permitting GDB to view it as a 32-bit application only. I.e, there's nothing that the application is going to do for which there will be a benefit to have a 64-bit view of it from the outside. Kevin