1: /*
   2:  * Copyright (c) 1989 The Regents of the University of California.
   3:  * All rights reserved.
   4:  *
   5:  * This code is derived from software contributed to Berkeley by
   6:  * Paul Vixie.
   7:  *
   8:  * Redistribution and use in source and binary forms are permitted
   9:  * provided that the above copyright notice and this paragraph are
  10:  * duplicated in all such forms and that any documentation,
  11:  * advertising materials, and other materials related to such
  12:  * distribution and use acknowledge that the software was developed
  13:  * by the University of California, Berkeley.  The name of the
  14:  * University may not be used to endorse or promote products derived
  15:  * from this software without specific prior written permission.
  16:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  17:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  18:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  19:  *
  20:  *	@(#)bitstring.h	5.2.1 (2.11BSD) 1999/8/5
  21:  */
  22: 
  23: typedef unsigned char bitstr_t;
  24: 
  25: /* internal macros */
  26:                 /* byte of the bitstring bit is in */
  27: #define _bit_byte(bit) \
  28:     ((bit) >> 3)
  29: 
  30:                 /* mask for the bit within its byte */
  31: #define _bit_mask(bit) \
  32:     (1 << ((bit)&0x7))
  33: 
  34: /* external macros */
  35:                 /* bytes in a bitstring of nbits bits */
  36: #define bitstr_size(nbits) \
  37:     ((((nbits) - 1) >> 3) + 1)
  38: 
  39:                 /* allocate a bitstring */
  40: #define bit_alloc(nbits) \
  41:     (bitstr_t *)calloc(1, \
  42:         (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
  43: 
  44:                 /* allocate a bitstring on the stack */
  45: #define bit_decl(name, nbits) \
  46:     (name)[bitstr_size(nbits)]
  47: 
  48:                 /* is bit N of bitstring name set? */
  49: #define bit_test(name, bit) \
  50:     ((name)[_bit_byte(bit)] & _bit_mask(bit))
  51: 
  52:                 /* set bit N of bitstring name */
  53: #define bit_set(name, bit) \
  54:     (name)[_bit_byte(bit)] |= _bit_mask(bit)
  55: 
  56:                 /* clear bit N of bitstring name */
  57: #define bit_clear(name, bit) \
  58:     (name)[_bit_byte(bit)] &= ~_bit_mask(bit)
  59: 
  60:                 /* clear bits start ... stop in bitstring */
  61: #define bit_nclear(name, start, stop) { \
  62:     register bitstr_t *_name = name; \
  63:     register int _start = start, _stop = stop; \
  64:     register int _startbyte = _bit_byte(_start); \
  65:     register int _stopbyte = _bit_byte(_stop); \
  66:     if (_startbyte == _stopbyte) { \
  67:         _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
  68:                       (0xff << ((_stop&0x7) + 1))); \
  69:     } else { \
  70:         _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
  71:         while (++_startbyte < _stopbyte) \
  72:             _name[_startbyte] = 0; \
  73:         _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
  74:     } \
  75: }
  76: 
  77:                 /* set bits start ... stop in bitstring */
  78: #define bit_nset(name, start, stop) { \
  79:     register bitstr_t *_name = name; \
  80:     register int _start = start, _stop = stop; \
  81:     register int _startbyte = _bit_byte(_start); \
  82:     register int _stopbyte = _bit_byte(_stop); \
  83:     if (_startbyte == _stopbyte) { \
  84:         _name[_startbyte] |= ((0xff << (_start&0x7)) & \
  85:                     (0xff >> (7 - (_stop&0x7)))); \
  86:     } else { \
  87:         _name[_startbyte] |= 0xff << ((_start)&0x7); \
  88:         while (++_startbyte < _stopbyte) \
  89:                 _name[_startbyte] = 0xff; \
  90:         _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
  91:     } \
  92: }
  93: 
  94:                 /* find first bit clear in name */
  95: #define bit_ffc(name, nbits, value) { \
  96:     register bitstr_t *_name = name; \
  97:     register int _byte, _nbits = nbits; \
  98:     register int _stopbyte = _bit_byte(_nbits), _value = -1; \
  99:     for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 100:         if (_name[_byte] != 0xff) { \
 101:             _value = _byte << 3; \
 102:             for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
 103:                 ++_value, _stopbyte >>= 1); \
 104:             break; \
 105:         } \
 106:     *(value) = _value; \
 107: }
 108: 
 109:                 /* find first bit set in name */
 110: #define bit_ffs(name, nbits, value) { \
 111:     register bitstr_t *_name = name; \
 112:     register int _byte, _nbits = nbits; \
 113:     register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 114:     for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 115:         if (_name[_byte]) { \
 116:             _value = _byte << 3; \
 117:             for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
 118:                 ++_value, _stopbyte >>= 1); \
 119:             break; \
 120:         } \
 121:     *(value) = _value; \
 122: }

Defined typedef's

bitstr_t defined in line 23; used 6 times

Defined macros

_bit_byte defined in line 27; used 9 times
_bit_mask defined in line 31; used 3 times
bit_alloc defined in line 40; never used
bit_clear defined in line 57; never used
bit_decl defined in line 45; never used
bit_ffc defined in line 95; never used
bit_ffs defined in line 110; never used
bit_nclear defined in line 61; never used
bit_nset defined in line 78; never used
bit_set defined in line 53; never used
bit_test defined in line 49; never used
bitstr_size defined in line 36; used 2 times
Last modified: 1999-08-06
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