From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 05 Sep 2002 18:20:06 +0200 (CEST) Received: from crack.them.org ([65.125.64.184]:47634 "EHLO crack.them.org") by linux-mips.org with ESMTP id ; Thu, 5 Sep 2002 18:20:05 +0200 Received: from nevyn.them.org ([66.93.61.169] ident=mail) by crack.them.org with asmtp (Exim 3.12 #1 (Debian)) id 17n0IA-0003Cf-00; Thu, 05 Sep 2002 12:19:42 -0500 Received: from drow by nevyn.them.org with local (Exim 3.35 #1 (Debian)) id 17mzLx-0001Jc-00; Thu, 05 Sep 2002 12:19:33 -0400 Date: Thu, 5 Sep 2002 12:19:33 -0400 From: Daniel Jacobowitz To: "Maciej W. Rozycki" Cc: Hartvig Ekner , "Kevin D. Kissell" , Tor Arntsen , Carsten Langgaard , Ralf Baechle , linux-mips@linux-mips.org Subject: Re: 64-bit and N32 kernel interfaces Message-ID: <20020905161933.GA5023@nevyn.them.org> References: <20020905151409.GA25023@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 119 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: dan@debian.org Precedence: bulk X-list: linux-mips On Thu, Sep 05, 2002 at 06:16:49PM +0200, Maciej W. Rozycki wrote: > On Thu, 5 Sep 2002, Daniel Jacobowitz wrote: > > > N32 supports saving and restoring 64-bit registers, which O32 doesn't - > > according to some comments in GCC, O32 is in fact incompatible with > > using 64-bit operations. > > But that old software wouldn't benefit as it didn't perform 64-bit > operations unless manually coded in software using narrower data types. > There is no 64-bit C data type for o32 and long long is quite a recent > invention -- it didn't exist in the 80s or even early 90s. Right. You don't recompile and get a magic bullet speed improvement (well, you do, but not a drastic one I think); but you don't recompile and get a magic bullet binary incompatibility either. Then you add 64-bit pieces by hand as necessary. That's my understanding anyway. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer