Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030380AbWBNFQc (ORCPT ); Tue, 14 Feb 2006 00:16:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030382AbWBNFNk (ORCPT ); Tue, 14 Feb 2006 00:13:40 -0500 Received: from ns.miraclelinux.com ([219.118.163.66]:28111 "EHLO mail01.miraclelinux.com") by vger.kernel.org with ESMTP id S1030380AbWBNFFG (ORCPT ); Tue, 14 Feb 2006 00:05:06 -0500 Message-Id: <20060214050444.599668000@localhost.localdomain> References: <20060214050351.252615000@localhost.localdomain> Date: Tue, 14 Feb 2006 14:04:06 +0900 From: Akinobu Mita To: linux-kernel@vger.kernel.org Cc: akpm@osdl.org, Richard Henderson , Ivan Kokshaysky , Russell King , Ian Molton , dev-etrax@axis.com, David Howells , Yoshinori Sato , Linus Torvalds , linux-ia64@vger.kernel.org, Hirokazu Takata , linux-m68k@vger.kernel.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 , Akinobu Mita Subject: [patch 15/47] generic hweight{64,32,16,8}() Content-Disposition: inline; filename=hweight-bitops.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3807 Lines: 111 This patch introduces the C-language equivalents of the functions below: unsigned int hweight32(unsigned int w); unsigned int hweight16(unsigned int w); unsigned int hweight8(unsigned int w); unsigned long hweight64(__u64 w); In include/asm-generic/bitops/hweight.h This code largely copied from: include/linux/bitops.h Signed-off-by: Akinobu Mita include/asm-generic/bitops/hweight.h | 9 +++++ lib/Makefile | 1 lib/hweight.c | 54 +++++++++++++++++++++++++++++++++++ 3 files changed, 64 insertions(+) Index: 2.6-rc/include/asm-generic/bitops/hweight.h =================================================================== --- /dev/null +++ 2.6-rc/include/asm-generic/bitops/hweight.h @@ -0,0 +1,9 @@ +#ifndef _ASM_GENERIC_BITOPS_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_HWEIGHT_H_ + +extern unsigned int hweight32(unsigned int w); +extern unsigned int hweight16(unsigned int w); +extern unsigned int hweight8(unsigned int w); +extern unsigned long hweight64(__u64 w); + +#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ Index: 2.6-rc/lib/Makefile =================================================================== --- 2.6-rc.orig/lib/Makefile +++ 2.6-rc/lib/Makefile @@ -21,6 +21,7 @@ lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_SEMAPHORE_SLEEPERS) += semaphore-sleepers.o lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o +lib-$(CONFIG_GENERIC_HWEIGHT) += hweight.o obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o Index: 2.6-rc/lib/hweight.c =================================================================== --- /dev/null +++ 2.6-rc/lib/hweight.c @@ -0,0 +1,54 @@ +#include +#include + +/** + * hweightN - returns the hamming weight of a N-bit word + * @x: the word to weigh + * + * The Hamming Weight of a number is the total number of bits set in it. + */ + +unsigned int hweight32(unsigned int w) +{ + unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); + res = (res & 0x33333333) + ((res >> 2) & 0x33333333); + res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); + res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); + return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); +} +EXPORT_SYMBOL(hweight32); + +unsigned int hweight16(unsigned int w) +{ + unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); + res = (res & 0x3333) + ((res >> 2) & 0x3333); + res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); + return (res & 0x00FF) + ((res >> 8) & 0x00FF); +} +EXPORT_SYMBOL(hweight16); + +unsigned int hweight8(unsigned int w) +{ + unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); + res = (res & 0x33) + ((res >> 2) & 0x33); + return (res & 0x0F) + ((res >> 4) & 0x0F); +} +EXPORT_SYMBOL(hweight8); + +unsigned long hweight64(__u64 w) +{ +#if BITS_PER_LONG == 32 + return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); +#elif BITS_PER_LONG == 64 + 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); +#else +#error BITS_PER_LONG not defined +#endif +} +EXPORT_SYMBOL(hweight64); -- - 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/