Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264569AbTGBCSB (ORCPT ); Tue, 1 Jul 2003 22:18:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264582AbTGBCSB (ORCPT ); Tue, 1 Jul 2003 22:18:01 -0400 Received: from pao-ex01.pao.digeo.com ([12.47.58.20]:56340 "EHLO pao-ex01.pao.digeo.com") by vger.kernel.org with ESMTP id S264569AbTGBCR7 (ORCPT ); Tue, 1 Jul 2003 22:17:59 -0400 Date: Tue, 1 Jul 2003 19:32:50 -0700 From: Andrew Morton To: Bernardo Innocenti Cc: linux-kernel@vger.kernel.org, torvalds@transmeta.com Subject: Re: [PATCH] Kill div64.h dupes, parenthesize do_div() macro params Message-Id: <20030701193250.1cbd4af9.akpm@digeo.com> In-Reply-To: <200307020424.47629.bernie@develer.com> References: <200307020232.20726.bernie@develer.com> <20030701173612.280d1296.akpm@digeo.com> <200307020424.47629.bernie@develer.com> X-Mailer: Sylpheed version 0.9.0pre1 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 02 Jul 2003 02:32:23.0200 (UTC) FILETIME=[2B1F5A00:01C34042] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 809 Lines: 21 Bernardo Innocenti wrote: > > By the way, what do you think about getting rid of the do_div() macro > altogether? I think we leave it the way it is because 64-bit divides are slow. It is very easy to go accidentally adding 64-bit divides. Say, by changing the disk indexing to use 64-bit sector numbers as we did earlier in 2.5. By requiring an explicit do_div we are made aware of all those 64-bit divides and are made to think about them. Why 64-bit divides in particular were victimised in this manner is a matter for speculation ;) - 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/