Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757317AbXKFSzr (ORCPT ); Tue, 6 Nov 2007 13:55:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754732AbXKFSzk (ORCPT ); Tue, 6 Nov 2007 13:55:40 -0500 Received: from astoria.ccjclearline.com ([64.235.106.9]:43096 "EHLO astoria.ccjclearline.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754971AbXKFSzj (ORCPT ); Tue, 6 Nov 2007 13:55:39 -0500 Date: Tue, 6 Nov 2007 13:53:29 -0500 (EST) From: "Robert P. J. Day" X-X-Sender: rpjday@localhost.localdomain To: Boaz Harrosh cc: Linux Kernel Mailing List , Andrew Morton , matthew@wil.cx Subject: Re: [PATCH] Add the macro to test if "exactly_one_bit_set" to log2.h. In-Reply-To: <4730AE66.6030501@panasas.com> Message-ID: References: <4730AE66.6030501@panasas.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - astoria.ccjclearline.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - crashcourse.ca X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1399 Lines: 43 On Tue, 6 Nov 2007, Boaz Harrosh wrote: > On Tue, Nov 06 2007 at 18:38 +0200, "Robert P. J. Day" wrote: > > While this macro is defined in terms of "is_power_of_2" and is > > therefore functionally equivalent, the visual semantics are sometimes > > more appropriate for what is actually being tested. > > > > Signed-off-by: Robert P. J. Day > > > > --- > > > > diff --git a/include/linux/log2.h b/include/linux/log2.h > > index c8cf5e8..d0d324e 100644 > > --- a/include/linux/log2.h > > +++ b/include/linux/log2.h > > @@ -55,6 +55,12 @@ bool is_power_of_2(unsigned long n) > > } > > > > /* > > + * And for folks who want slightly different semantics ... > > + */ > > + > > +#define exactly_one_bit_set is_power_of_2 > > at_most_one_bit_set No? no, it really is *exactly* one bit set. zero is not considered a power of two. rday -- ======================================================================== Robert P. J. Day Linux Consulting, Training and Annoying Kernel Pedantry Waterloo, Ontario, CANADA http://crashcourse.ca ======================================================================== - 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/