Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030383AbWBNFTS (ORCPT ); Tue, 14 Feb 2006 00:19:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030448AbWBNFTR (ORCPT ); Tue, 14 Feb 2006 00:19:17 -0500 Received: from ns.miraclelinux.com ([219.118.163.66]:15823 "EHLO mail01.miraclelinux.com") by vger.kernel.org with ESMTP id S1030359AbWBNFFE (ORCPT ); Tue, 14 Feb 2006 00:05:04 -0500 Message-Id: <20060214050443.645438000@localhost.localdomain> References: <20060214050351.252615000@localhost.localdomain> Date: Tue, 14 Feb 2006 14:04:01 +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, Yoshinori Sato , Hirokazu Takata , Greg Ungerer , linux-mips@linux-mips.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 , Akinobu Mita Subject: [patch 10/47] generic fls() Content-Disposition: inline; filename=fls-bitops.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1448 Lines: 65 This patch introduces the C-language equivalent of the function: int fls(int x); In include/asm-generic/bitops/fls.h This code largely copied from: include/linux/bitops.h Signed-off-by: Akinobu Mita include/asm-generic/bitops/fls.h | 41 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 41 insertions(+) Index: 2.6-rc/include/asm-generic/bitops/fls.h =================================================================== --- /dev/null +++ 2.6-rc/include/asm-generic/bitops/fls.h @@ -0,0 +1,41 @@ +#ifndef _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ + +static inline int fls(int x) +{ + int r = 32; + + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ -- - 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/