1 /* $OpenBSD: bitstring.h,v 1.7 2024/08/26 11:52:54 bluhm Exp $ */ 2 /* $NetBSD: bitstring.h,v 1.5 1997/05/14 15:49:55 pk Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Paul Vixie. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)bitstring.h 8.1 (Berkeley) 7/19/93 36 */ 37 38 #ifndef _BITSTRING_H_ 39 #define _BITSTRING_H_ 40 41 /* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91 42 * bitstr_size changed gratuitously, but shorter 43 * bit_alloc spelling error fixed 44 * the following were efficient, but didn't work, they've been made to 45 * work, but are no longer as efficient :-) 46 * bit_nclear, bit_nset, bit_ffc, bit_ffs 47 */ 48 typedef unsigned char bitstr_t; 49 50 /* internal macros */ 51 /* byte of the bitstring bit is in */ 52 #define _bit_byte(bit) \ 53 ((bit) >> 3) 54 55 /* mask for the bit within its byte */ 56 #define _bit_mask(bit) \ 57 (1 << ((bit)&0x7)) 58 59 /* external macros */ 60 /* bytes in a bitstring of nbits bits */ 61 #define bitstr_size(nbits) \ 62 (((nbits) + 7) >> 3) 63 64 /* allocate a bitstring */ 65 #define bit_alloc(nbits) \ 66 (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t)) 67 68 /* allocate a bitstring on the stack */ 69 #define bit_decl(name, nbits) \ 70 ((name)[bitstr_size(nbits)]) 71 72 /* is bit N of bitstring name set? */ 73 #define bit_test(name, bit) ({ \ 74 register int __tbit = (bit); \ 75 ((name)[_bit_byte(__tbit)] & _bit_mask(__tbit)); \ 76 }) 77 78 /* set bit N of bitstring name */ 79 #define bit_set(name, bit) do { \ 80 register int __sbit = (bit); \ 81 ((name)[_bit_byte(__sbit)] |= _bit_mask(__sbit)); \ 82 } while(0) 83 84 /* clear bit N of bitstring name */ 85 #define bit_clear(name, bit) do { \ 86 register int __cbit = (bit); \ 87 ((name)[_bit_byte(__cbit)] &= ~_bit_mask(__cbit)); \ 88 } while(0) 89 90 /* clear bits start ... stop in bitstring */ 91 #define bit_nclear(name, start, stop) do { \ 92 register bitstr_t *__name = (name); \ 93 register int __start = (start), __stop = (stop); \ 94 while (__start <= __stop) { \ 95 bit_clear(__name, __start); \ 96 __start++; \ 97 } \ 98 } while(0) 99 100 /* set bits start ... stop in bitstring */ 101 #define bit_nset(name, start, stop) do { \ 102 register bitstr_t *__name = (name); \ 103 register int __start = (start), __stop = (stop); \ 104 while (__start <= __stop) { \ 105 bit_set(__name, __start); \ 106 __start++; \ 107 } \ 108 } while(0) 109 110 /* find first bit clear in name */ 111 #define bit_ffc(name, nbits, value) do { \ 112 register bitstr_t *__name = (name); \ 113 register int __bit, __nbits = (nbits), __value = -1; \ 114 for (__bit = 0; __bit < __nbits; ++__bit) \ 115 if (!bit_test(__name, __bit)) { \ 116 __value = __bit; \ 117 break; \ 118 } \ 119 *(value) = __value; \ 120 } while(0) 121 122 /* find first bit set in name */ 123 #define bit_ffs(name, nbits, value) do { \ 124 register bitstr_t *__name = (name); \ 125 register int __bit, __nbits = (nbits), __value = -1; \ 126 for (__bit = 0; __bit < __nbits; ++__bit) \ 127 if (bit_test(__name, __bit)) { \ 128 __value = __bit; \ 129 break; \ 130 } \ 131 *(value) = __value; \ 132 } while(0) 133 134 #endif /* !_BITSTRING_H_ */ 135