From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759713AbZENOJs (ORCPT ); Thu, 14 May 2009 10:09:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754027AbZENOJj (ORCPT ); Thu, 14 May 2009 10:09:39 -0400 Received: from terminus.zytor.com ([198.137.202.10]:55660 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752982AbZENOJi (ORCPT ); Thu, 14 May 2009 10:09:38 -0400 Message-ID: <4A0C2614.4010803@zytor.com> Date: Thu, 14 May 2009 07:09:24 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Sheng Yang CC: linux-kernel@vger.kernel.org, linux-mm , Ingo Molnar Subject: Re: [PATCH] x86: Extend test_and_set_bit() test_and_clean_bit() to 64 bits in X86_64 References: <1242202647-32446-1-git-send-email-sheng@linux.intel.com> <4A0AFB7D.2080105@zytor.com> <4A0B036B.7000107@zytor.com> <200905141152.29378.sheng@linux.intel.com> In-Reply-To: <200905141152.29378.sheng@linux.intel.com> 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 Sheng Yang wrote: > > Yeah, this one also works well(lightly tested). :) > > But one thing should be noticed that, bit ops recognized the input as signed. > According to SDM 2A 3.1.1.7 Operation Section, Bit(BitBase, BitOffset) can > accept BitOffset as negative value, then search backward... Well, I indeed > don't know when we need this, but I think keep signed here should be better... > Urk, you're right. How daft. I had preferred to switch it to unsigned long to match MIPS and SPARC, but that probably is a good reason to leave it signed. Pain. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.