From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 08 Sep 2002 18:13:29 +0200 (CEST) Received: from p508B4F9D.dip.t-dialin.net ([80.139.79.157]:30848 "EHLO dea.linux-mips.net") by linux-mips.org with ESMTP id ; Sun, 8 Sep 2002 18:13:28 +0200 Received: (from ralf@localhost) by dea.linux-mips.net (8.11.6/8.11.6) id g869gdG04428; Fri, 6 Sep 2002 11:42:39 +0200 Date: Fri, 6 Sep 2002 11:42:39 +0200 From: Ralf Baechle To: "Maciej W. Rozycki" Cc: Daniel Jacobowitz , Hartvig Ekner , "Kevin D. Kissell" , Tor Arntsen , Carsten Langgaard , linux-mips@linux-mips.org Subject: Re: 64-bit and N32 kernel interfaces Message-ID: <20020906114239.B2993@linux-mips.org> References: <20020905151409.GA25023@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from macro@ds2.pg.gda.pl on Thu, Sep 05, 2002 at 06:16:49PM +0200 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: 145 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: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Thu, Sep 05, 2002 at 06:16:49PM +0200, Maciej W. Rozycki 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. Not in any standard but de facto in existence since a long time. Anyway, the changes in floating point in the N32 are so substancial that there are projects that say without N32 or N64 they don't even need to start working on their projects. Ralf