From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932199Ab3LTKs6 (ORCPT ); Fri, 20 Dec 2013 05:48:58 -0500 Received: from multi.imgtec.com ([194.200.65.239]:18898 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932115Ab3LTKsy (ORCPT ); Fri, 20 Dec 2013 05:48:54 -0500 Message-ID: <52B4208B.1080801@imgtec.com> Date: Fri, 20 Dec 2013 10:48:43 +0000 From: James Hogan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Chen Gang CC: , "linux-kernel@vger.kernel.org" , Subject: Re: [PATCH] arch: metag: lib: add "umoddi3.S" file for __umoddi3() References: <52B2E0FA.7090805@gmail.com> <52B2E3DB.7010008@imgtec.com> <52B2F6B7.1050802@gmail.com> <52B2F8DC.8060006@imgtec.com> <52B3A0EA.9010801@gmail.com> <52B40E44.9040603@imgtec.com> <52B419DE.8050706@gmail.com> In-Reply-To: <52B419DE.8050706@gmail.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.65] X-SEF-Processed: 7_3_0_01192__2013_12_20_10_48_44 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/12/13 10:20, Chen Gang wrote: > Hmm... but do you know why we need some 64-bit functions which are > implemented under "arch/metag/lib/*.S"? can we use > instead of them? (e.g 64-bit '/'). If you look at linux/math64.h you'll see it only implements division operations. The other 64 bit operations like shift, compare, and multiply are relatively cheap so are implemented as intrinsics instead. Cheers James