From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932082AbWAZDgs (ORCPT ); Wed, 25 Jan 2006 22:36:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932181AbWAZDgr (ORCPT ); Wed, 25 Jan 2006 22:36:47 -0500 Received: from ns.miraclelinux.com ([219.118.163.66]:25573 "EHLO mail01.miraclelinux.com") by vger.kernel.org with ESMTP id S932082AbWAZDgq (ORCPT ); Wed, 25 Jan 2006 22:36:46 -0500 Date: Thu, 26 Jan 2006 12:36:52 +0900 To: Grant Grundler Cc: Linux Kernel Development , linux-ia64@vger.kernel.org Subject: [PATCH 9/12] generic hweight64() Message-ID: <20060126033652.GH11138@miraclelinux.com> References: <20060125112625.GA18584@miraclelinux.com> <20060125113206.GD18584@miraclelinux.com> <20060125200250.GA26443@flint.arm.linux.org.uk> <20060125205907.GF9995@esmail.cup.hp.com> <20060126032713.GA9984@miraclelinux.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060126032713.GA9984@miraclelinux.com> User-Agent: Mutt/1.5.9i From: mita@miraclelinux.com (Akinobu Mita) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces the C-language equivalent of the function: unsigned long hweight64(__u64 w); HAVE_ARCH_HWEIGHT64_BITOPS is defined when the architecture has its own version of these functions. This code largely copied from: include/linux/bitops.h Index: 2.6-git/include/asm-generic/bitops.h =================================================================== --- 2.6-git.orig/include/asm-generic/bitops.h 2006-01-25 19:14:11.000000000 +0900 +++ 2.6-git/include/asm-generic/bitops.h 2006-01-25 19:14:11.000000000 +0900 @@ -491,6 +491,25 @@ #endif /* HAVE_ARCH_HWEIGHT_BITOPS */ +#ifndef HAVE_ARCH_HWEIGHT64_BITOPS + +static inline unsigned long hweight64(__u64 w) +{ +#if BITS_PER_LONG < 64 + return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); +#else + u64 res; + res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul); + res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); + res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful); + res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul); + res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul); + return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul); +#endif +} + +#endif /* HAVE_ARCH_HWEIGHT64_BITOPS */ + #endif /* __KERNEL__ */ #endif /* _ASM_GENERIC_BITOPS_H */