From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from colo.lackof.org (colo.lackof.org [198.49.126.79]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.lackof.org", Issuer "ca.lackof.org" (not verified)) by ozlabs.org (Postfix) with ESMTP id 2015867EC8 for ; Fri, 27 Jan 2006 03:33:58 +1100 (EST) Date: Thu, 26 Jan 2006 09:18:49 -0700 From: Grant Grundler To: Akinobu Mita , linux-kernel@vger.kernel.org, Ivan Kokshaysky , Ian Molton , dev-etrax@axis.com, David Howells , Yoshinori Sato , Linus Torvalds , linux-ia64@vger.kernel.org, Hirokazu Takata , linux-m68k@lists.linux-m68k.org, Greg Ungerer , linux-mips@linux-mips.org, parisc-linux@parisc-linux.org, linuxppc-dev@ozlabs.org, linux390@de.ibm.com, linuxsh-dev@lists.sourceforge.net, linuxsh-shmedia-dev@lists.sourceforge.net, sparclinux@vger.kernel.org, ultralinux@vger.kernel.org, Miles Bader , Andi Kleen , Chris Zankel Subject: Re: [parisc-linux] Re: [PATCH 3/6] C-language equivalents of include/asm-*/bitops.h Message-ID: <20060126161849.GA13632@colo.lackof.org> References: <20060125112625.GA18584@miraclelinux.com> <20060125113206.GD18584@miraclelinux.com> <20060125200250.GA26443@flint.arm.linux.org.uk> <20060126000618.GA5592@twiddle.net> <20060126085540.GA15377@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20060126085540.GA15377@flint.arm.linux.org.uk> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Jan 26, 2006 at 08:55:41AM +0000, Russell King wrote: > Unfortunately that's not correct. You do not appear to have checked > the compiler output like I did - this code does _not_ generate > constant shifts. Russell, By "written stupidly", I thought Richard meant they could have used constants instead of "s". e.g.: if (word << 16 == 0) { b += 16; word >>= 16); } if (word << 24 == 0) { b += 8; word >>= 8); } if (word << 28 == 0) { b += 4; word >>= 4); } But I prefer what Edgar Toernig suggested. grant