bitstring.h 4.2 KB

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  1. /* $OpenBSD: bitstring.h,v 1.5 2003/06/02 19:34:12 millert Exp $ */
  2. /* $NetBSD: bitstring.h,v 1.5 1997/05/14 15:49:55 pk Exp $ */
  3. /*
  4. * Copyright (c) 1989, 1993
  5. * The Regents of the University of California. All rights reserved.
  6. *
  7. * This code is derived from software contributed to Berkeley by
  8. * Paul Vixie.
  9. *
  10. * Redistribution and use in source and binary forms, with or without
  11. * modification, are permitted provided that the following conditions
  12. * are met:
  13. * 1. Redistributions of source code must retain the above copyright
  14. * notice, this list of conditions and the following disclaimer.
  15. * 2. Redistributions in binary form must reproduce the above copyright
  16. * notice, this list of conditions and the following disclaimer in the
  17. * documentation and/or other materials provided with the distribution.
  18. * 3. Neither the name of the University nor the names of its contributors
  19. * may be used to endorse or promote products derived from this software
  20. * without specific prior written permission.
  21. *
  22. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32. * SUCH DAMAGE.
  33. *
  34. * @(#)bitstring.h 8.1 (Berkeley) 7/19/93
  35. */
  36. #ifndef _BITSTRING_H_
  37. #define _BITSTRING_H_
  38. /* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91
  39. * bitstr_size changed gratuitously, but shorter
  40. * bit_alloc spelling error fixed
  41. * the following were efficient, but didn't work, they've been made to
  42. * work, but are no longer as efficient :-)
  43. * bit_nclear, bit_nset, bit_ffc, bit_ffs
  44. */
  45. typedef unsigned char bitstr_t;
  46. /* internal macros */
  47. /* byte of the bitstring bit is in */
  48. #define _bit_byte(bit) \
  49. ((bit) >> 3)
  50. /* mask for the bit within its byte */
  51. #define _bit_mask(bit) \
  52. (1 << ((bit)&0x7))
  53. /* external macros */
  54. /* bytes in a bitstring of nbits bits */
  55. #define bitstr_size(nbits) \
  56. (((nbits) + 7) >> 3)
  57. /* allocate a bitstring */
  58. #define bit_alloc(nbits) \
  59. (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
  60. /* allocate a bitstring on the stack */
  61. #define bit_decl(name, nbits) \
  62. ((name)[bitstr_size(nbits)])
  63. /* is bit N of bitstring name set? */
  64. #define bit_test(name, bit) \
  65. ((name)[_bit_byte(bit)] & _bit_mask(bit))
  66. /* set bit N of bitstring name */
  67. #define bit_set(name, bit) \
  68. ((name)[_bit_byte(bit)] |= _bit_mask(bit))
  69. /* clear bit N of bitstring name */
  70. #define bit_clear(name, bit) \
  71. ((name)[_bit_byte(bit)] &= ~_bit_mask(bit))
  72. /* clear bits start ... stop in bitstring */
  73. #define bit_nclear(name, start, stop) do { \
  74. register bitstr_t *_name = name; \
  75. register int _start = start, _stop = stop; \
  76. while (_start <= _stop) { \
  77. bit_clear(_name, _start); \
  78. _start++; \
  79. } \
  80. } while(0)
  81. /* set bits start ... stop in bitstring */
  82. #define bit_nset(name, start, stop) do { \
  83. register bitstr_t *_name = name; \
  84. register int _start = start, _stop = stop; \
  85. while (_start <= _stop) { \
  86. bit_set(_name, _start); \
  87. _start++; \
  88. } \
  89. } while(0)
  90. /* find first bit clear in name */
  91. #define bit_ffc(name, nbits, value) do { \
  92. register bitstr_t *_name = name; \
  93. register int _bit, _nbits = nbits, _value = -1; \
  94. for (_bit = 0; _bit < _nbits; ++_bit) \
  95. if (!bit_test(_name, _bit)) { \
  96. _value = _bit; \
  97. break; \
  98. } \
  99. *(value) = _value; \
  100. } while(0)
  101. /* find first bit set in name */
  102. #define bit_ffs(name, nbits, value) do { \
  103. register bitstr_t *_name = name; \
  104. register int _bit, _nbits = nbits, _value = -1; \
  105. for (_bit = 0; _bit < _nbits; ++_bit) \
  106. if (bit_test(_name, _bit)) { \
  107. _value = _bit; \
  108. break; \
  109. } \
  110. *(value) = _value; \
  111. } while(0)
  112. #endif /* !_BITSTRING_H_ */