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Diffstat (limited to 'compat/bitstring.h')
| -rw-r--r-- | compat/bitstring.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/compat/bitstring.h b/compat/bitstring.h new file mode 100644 index 0000000..8fc3423 --- /dev/null +++ b/compat/bitstring.h @@ -0,0 +1,128 @@ +/* $OpenBSD: bitstring.h,v 1.5 2003/06/02 19:34:12 millert Exp $ */ +/* $NetBSD: bitstring.h,v 1.5 1997/05/14 15:49:55 pk 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 + */ +typedef unsigned char bitstr_t; + +/* internal macros */ + /* byte of the bitstring bit is in */ +#define _bit_byte(bit) \ + ((bit) >> 3) + + /* mask for the bit within its byte */ +#define _bit_mask(bit) \ + (1 << ((bit)&0x7)) + +/* external macros */ + /* bytes in a bitstring of nbits bits */ +#define bitstr_size(nbits) \ + (((nbits) + 7) >> 3) + + /* allocate a bitstring */ +#define bit_alloc(nbits) \ + (bitstr_t *)calloc((size_t)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) \ + ((name)[_bit_byte(bit)] & _bit_mask(bit)) + + /* set bit N of bitstring name */ +#define bit_set(name, bit) \ + ((name)[_bit_byte(bit)] |= _bit_mask(bit)) + + /* clear bit N of bitstring name */ +#define bit_clear(name, bit) \ + ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) + + /* clear bits start ... stop in bitstring */ +#define bit_nclear(name, start, stop) do { \ + register bitstr_t *_name = name; \ + register int _start = start, _stop = stop; \ + while (_start <= _stop) { \ + bit_clear(_name, _start); \ + _start++; \ + } \ +} while(0) + + /* set bits start ... stop in bitstring */ +#define bit_nset(name, start, stop) do { \ + register bitstr_t *_name = name; \ + register int _start = start, _stop = stop; \ + while (_start <= _stop) { \ + bit_set(_name, _start); \ + _start++; \ + } \ +} while(0) + + /* find first bit clear in name */ +#define bit_ffc(name, nbits, value) do { \ + register bitstr_t *_name = name; \ + register int _bit, _nbits = nbits, _value = -1; \ + for (_bit = 0; _bit < _nbits; ++_bit) \ + if (!bit_test(_name, _bit)) { \ + _value = _bit; \ + break; \ + } \ + *(value) = _value; \ +} while(0) + + /* find first bit set in name */ +#define bit_ffs(name, nbits, value) do { \ + register bitstr_t *_name = name; \ + register int _bit, _nbits = nbits, _value = -1; \ + for (_bit = 0; _bit < _nbits; ++_bit) \ + if (bit_test(_name, _bit)) { \ + _value = _bit; \ + break; \ + } \ + *(value) = _value; \ +} while(0) + +#endif /* !_BITSTRING_H_ */ |