Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758087AbZADUkd (ORCPT ); Sun, 4 Jan 2009 15:40:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752042AbZADUkX (ORCPT ); Sun, 4 Jan 2009 15:40:23 -0500 Received: from terminus.zytor.com ([198.137.202.10]:40388 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751140AbZADUkW (ORCPT ); Sun, 4 Jan 2009 15:40:22 -0500 Message-ID: <49611E88.6010204@zytor.com> Date: Sun, 04 Jan 2009 12:39:36 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Rob Landley CC: Alan Cox , Sam Ravnborg , Embedded Linux mailing list , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH 1/3]: Replace kernel/timeconst.pl with kernel/timeconst.sh References: <200901020207.30359.rob@landley.net> <200901031932.51873.rob@landley.net> <20090104120735.72840fdb@lxorguk.ukuu.org.uk> <200901041303.12687.rob@landley.net> In-Reply-To: <200901041303.12687.rob@landley.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 815 Lines: 23 Rob Landley wrote: > > C) The only calculation which can overflow 64 bits (the ADJ32 one) turns out > not to need arbitrary precision math, just 72 bits, and if it ever uses more > than 32 then bottom 32 are all zero before the divide so you can do it in > three lines. > ... for the current code (32 bits). When we get an overflow-less 64-bit implementation, this code will have to be redone, which is not true for a properly done implementation. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/