LCOM1920-T02G10

/*        $NetBSD: bitstring.h,v 1.9 2010/05/06 18:54:22 christos Exp $        */

/*

 * Copyright (c) 1989, 1993

 *        The Regents of the University of California.  All rights reserved.

 *

 * This code is derived from software contributed to Berkeley by

 * Paul Vixie.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 *        @(#)bitstring.h        8.1 (Berkeley) 7/19/93

 */

#ifndef _BITSTRING_H_

#define        _BITSTRING_H_

/* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91

 * bitstr_size changed gratuitously, but shorter

 * bit_alloc   spelling error fixed

 * the following were efficient, but didn't work, they've been made to

 * work, but are no longer as efficient :-)

 * bit_nclear, bit_nset, bit_ffc, bit_ffs

 */

/*

 * The comment above may or may not bear any resemblance to reality.

 * This code has been maintained in a confusing way, with little

 * information available on the provenance of much of it. "At least it

 * works."

 *  /s/ Perry E. Metzger, 2 Feb 98

 */

typedef        unsigned char bitstr_t;

/* internal macros */

                                /* byte of the bitstring bit is in */

#define        _bit_byte(bit) \

        (uint32_t)((bit) >> 3)

                                /* mask for the bit within its byte */

#define        _bit_mask(bit) \

        (uint32_t)((1 << (uint32_t)((bit)&0x7)))

/* external macros */

                                /* bytes in a bitstring of nbits bits */

#define        bitstr_size(nbits) \

        (size_t)((uint32_t)((nbits) + 7) >> 3)

                                /* allocate a bitstring */

#define        bit_alloc(nbits) \

        calloc(bitstr_size(nbits), sizeof(bitstr_t))

                                /* allocate a bitstring on the stack */

#define        bit_decl(name, nbits) \

        ((name)[bitstr_size(nbits)])

                                /* is bit N of bitstring name set? */

#define        bit_test(name, bit) \

        /*LINTED bitwise on signed*/((name)[_bit_byte(bit)] & _bit_mask(bit))

                                /* set bit N of bitstring name */

#define        bit_set(name, bit) \

        /*LINTED bitwise on signed*/((name)[_bit_byte(bit)] |= _bit_mask(bit))

                                /* clear bit N of bitstring name */

#define        bit_clear(name, bit) \

        /*LINTED bitwise on signed*/((name)[_bit_byte(bit)] &= ~_bit_mask(bit))

                                /* clear bits start ... stop in bitstring */

#define        bit_nclear(name, start, stop) do { \

        bitstr_t *_name = name; \

        int _start = start, _stop = stop; \

        while (_start <= _stop) { \

                bit_clear(_name, _start); \

                _start++; \

        } \

} while(/*CONSTCOND*/0)

                                /* set bits start ... stop in bitstring */

#define        bit_nset(name, start, stop) do { \

        bitstr_t *_name = name; \

        int _start = start, _stop = stop; \

        while (_start <= _stop) { \

                bit_set(_name, _start); \

                _start++; \

        } \

} while(/*CONSTCOND*/0)

                                /* find first bit clear in name */

#define        bit_ffc(name, nbits, value) do { \

        bitstr_t *_name = name; \

        int _bit, _nbits = nbits, _value = -1; \

        for (_bit = 0; _bit < _nbits; ++_bit) \

                if (!bit_test(_name, _bit)) { \

                        _value = _bit; \

                        break; \

                } \

        *(value) = _value; \

} while(/*CONSTCOND*/0)

                                /* find first bit set in name */

#define        bit_ffs(name, nbits, value) do { \

        bitstr_t *_name = name; \

        int _bit, _nbits = nbits, _value = -1; \

        for (_bit = 0; _bit < _nbits; ++_bit) \

                if (bit_test(_name, _bit)) { \

                        _value = _bit; \

                        break; \

                } \

        *(value) = _value; \

} while(/*CONSTCOND*/0)

#endif /* !_BITSTRING_H_ */