From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from oss.sgi.com (localhost.localdomain [127.0.0.1]) by oss.sgi.com (8.12.3/8.12.3) with ESMTP id g3C53b8d024038 for ; Thu, 11 Apr 2002 22:03:37 -0700 Received: (from majordomo@localhost) by oss.sgi.com (8.12.3/8.12.3/Submit) id g3C53bOm024037 for linux-mips-outgoing; Thu, 11 Apr 2002 22:03:37 -0700 X-Authentication-Warning: oss.sgi.com: majordomo set sender to owner-linux-mips@oss.sgi.com using -f Received: from dea.linux-mips.net (localhost.localdomain [127.0.0.1]) by oss.sgi.com (8.12.3/8.12.3) with ESMTP id g3C53X8d024033 for ; Thu, 11 Apr 2002 22:03:34 -0700 Received: (from ralf@localhost) by dea.linux-mips.net (8.11.6/8.11.1) id g3C542p26971; Thu, 11 Apr 2002 22:04:02 -0700 Date: Thu, 11 Apr 2002 22:04:01 -0700 From: Ralf Baechle To: Rani Assaf Cc: linux-mips@oss.sgi.com Subject: Re: Question about r4k_clear_page_xxx() Message-ID: <20020411220401.A26953@dea.linux-mips.net> References: <20020410041408.G23127@paname.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: <20020410041408.G23127@paname.org>; from rani@paname.org on Wed, Apr 10, 2002 at 04:14:08AM +0200 X-Accept-Language: de,en,fr Sender: owner-linux-mips@oss.sgi.com Precedence: bulk On Wed, Apr 10, 2002 at 04:14:08AM +0200, Rani Assaf wrote: > I was cleaning duplicate code between my port of IDT RC32355 and the > current tree. I want to use r4k_clear_page_d16() but the function uses > store double (sd) which is not available on this processor. > > What's the reason for having r4k_clear_page_xxx() use store double and > not r4k_copy_page_xxx()?? The 32-bit kernel doesn't save or restore the upper 32-bits of general purpose registers. Therefore 64-bit stores can only be used with the $zero register. Ralf