diff options
author | Theo de Raadt <deraadt@cvs.openbsd.org> | 1995-10-18 08:53:40 +0000 |
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committer | Theo de Raadt <deraadt@cvs.openbsd.org> | 1995-10-18 08:53:40 +0000 |
commit | d6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch) | |
tree | ece253b876159b39c620e62b6c9b1174642e070e /include/bitstring.h |
initial import of NetBSD tree
Diffstat (limited to 'include/bitstring.h')
-rw-r--r-- | include/bitstring.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/include/bitstring.h b/include/bitstring.h new file mode 100644 index 00000000000..5966a1d3f5d --- /dev/null +++ b/include/bitstring.h @@ -0,0 +1,115 @@ +/* $NetBSD: bitstring.h,v 1.4 1994/10/26 00:55:45 cgd Exp $ */ + +/* + * Copyright (c) 1989 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 are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * @(#)bitstring.h 5.2 (Berkeley) 4/4/90 + */ + +#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) { \ + register bitstr_t *_name = name; \ + register int _start = start, _stop = stop; \ + while (_start <= _stop) { \ + bit_clear(_name, _start); \ + _start++; \ + } \ +} + + /* set bits start ... stop in bitstring */ +#define bit_nset(name, start, stop) { \ + register bitstr_t *_name = name; \ + register int _start = start, _stop = stop; \ + while (_start <= _stop) { \ + bit_set(_name, _start); \ + _start++; \ + } \ +} + + /* find first bit clear in name */ +#define bit_ffc(name, nbits, value) { \ + 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; \ +} + + /* find first bit set in name */ +#define bit_ffs(name, nbits, value) { \ + 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; \ +} + +#endif /* !_BITSTRING_H_ */ |