From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752703Ab0E1R61 (ORCPT ); Fri, 28 May 2010 13:58:27 -0400 Received: from king.tilera.com ([72.1.168.226]:7758 "EHLO king.tilera.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121Ab0E1R6Z (ORCPT ); Fri, 28 May 2010 13:58:25 -0400 Message-ID: <4C00043C.5030804@tilera.com> Date: Fri, 28 May 2010 13:58:20 -0400 From: Chris Metcalf User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: Marc Gauthier CC: Arnd Bergmann , Linux Kernel Mailing List , Linus Torvalds , "linux-arch@vger.kernel.org" Subject: Re: [PATCH] arch/tile: new multi-core architecture for Linux References: <201005200543.o4K5hFRF006079@farm-0002.internal.tilera.com> <201005271041.30519.arnd@arndb.de> <4BFE73DF.5090107@tilera.com> <201005271611.47963.arnd@arndb.de> <522C1DF17AF50042AD8AE87F7887BD3D01637144CA@exch.hq.tensilica.com> In-Reply-To: <522C1DF17AF50042AD8AE87F7887BD3D01637144CA@exch.hq.tensilica.com> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 28 May 2010 17:58:23.0158 (UTC) FILETIME=[5D3DA560:01CAFE8F] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/27/2010 10:52 AM, Marc Gauthier wrote: >>> We use [a syscall] not for the floating-point operations, but for integer >>> divide-by-zero. In principle we could use it for floating-point too, >>> but we currently don't, since generally folks don't expect it there. >>> >> Ah, I see. That probably makes a lot of sense to present as a signal >> the way you do. >> > FWIW, this can also be done using some recognizable illegal > instruction sequence, if the architecture reserves some opcodes > as always illegal. We do reserve a range of illegal values, and this is a great idea. I've removed the syscall from our kernel, and will add support for the appropriate magic in the trap handler once we pick an encoding and give it a name in the assembler. -- Chris Metcalf, Tilera Corp. http://www.tilera.com