1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * Architecture specific definition for bitmap related routines. 30 * These may be implemented using ISA specific instructions. 31 */ 32 #include <sys/bitmap.h> 33 34 /* 35 * Find highest one bit set. 36 * Returns bit number + 1 of highest bit that is set, otherwise returns 0. 37 * High order bit is 31 (or 63 in _LP64 kernel). 38 */ 39 int 40 highbit(ulong_t i) 41 { 42 register int h = 1; 43 44 if (i == 0) 45 return (0); 46 #ifdef _LP64 47 if (i & 0xffffffff00000000ul) { 48 h += 32; i >>= 32; 49 } 50 #endif 51 if (i & 0xffff0000) { 52 h += 16; i >>= 16; 53 } 54 if (i & 0xff00) { 55 h += 8; i >>= 8; 56 } 57 if (i & 0xf0) { 58 h += 4; i >>= 4; 59 } 60 if (i & 0xc) { 61 h += 2; i >>= 2; 62 } 63 if (i & 0x2) { 64 h += 1; 65 } 66 return (h); 67 } 68 69 /* 70 * Find lowest one bit set. 71 * Returns bit number + 1 of lowest bit that is set, otherwise returns 0. 72 * Low order bit is 0. 73 */ 74 int 75 lowbit(ulong_t i) 76 { 77 register int h = 1; 78 79 if (i == 0) 80 return (0); 81 82 #ifdef _LP64 83 if (!(i & 0xffffffff)) { 84 h += 32; i >>= 32; 85 } 86 #endif 87 if (!(i & 0xffff)) { 88 h += 16; i >>= 16; 89 } 90 if (!(i & 0xff)) { 91 h += 8; i >>= 8; 92 } 93 if (!(i & 0xf)) { 94 h += 4; i >>= 4; 95 } 96 if (!(i & 0x3)) { 97 h += 2; i >>= 2; 98 } 99 if (!(i & 0x1)) { 100 h += 1; 101 } 102 return (h); 103 } 104