/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. */ #include "lint.h" #include <string.h> #include <strings.h> #include <sys/types.h> static int ffs_impl(uint64_t bits) { int i = 1; uint32_t bits32; if (bits == 0) return (0); if ((bits32 = (uint32_t)bits) == 0) { bits32 = (uint32_t)(bits >> 32); i += 32; } if ((bits32 & 0xffff) == 0) { bits32 >>= 16; i += 16; } if ((bits32 & 0xff) == 0) { bits32 >>= 8; i += 8; } if ((bits32 & 0xf) == 0) { bits32 >>= 4; i += 4; } if ((bits32 & 0x3) == 0) { bits32 >>= 2; i += 2; } if ((bits32 & 0x1) == 0) i += 1; return (i); } int ffs(int bits) { return (ffs_impl((uint64_t)(uint_t)bits)); } int ffsl(long bits) { return (ffs_impl((uint64_t)(ulong_t)bits)); } int ffsll(long long bits) { return (ffs_impl((uint64_t)(u_longlong_t)bits)); }