#ifndef _BITSTRING_H_
#define _BITSTRING_H_
typedef unsigned char bitstr_t;
#define _bit_byte(bit) \
((bit) >> 3)
#define _bit_mask(bit) \
(1 << ((bit)&0x7))
#define bitstr_size(nbits) \
(((nbits) + 7) >> 3)
#define bit_alloc(nbits) \
(bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
#define bit_decl(name, nbits) \
((name)[bitstr_size(nbits)])
#define bit_test(name, bit) \
((name)[_bit_byte(bit)] & _bit_mask(bit))
#define bit_set(name, bit) \
((name)[_bit_byte(bit)] |= _bit_mask(bit))
#define bit_clear(name, bit) \
((name)[_bit_byte(bit)] &= ~_bit_mask(bit))
#define bit_nclear(name, start, stop) do { \
bitstr_t *_name = (name); \
int _start = (start), _stop = (stop); \
int _startbyte = _bit_byte(_start); \
int _stopbyte = _bit_byte(_stop); \
if (_startbyte == _stopbyte) { \
_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
(0xff << ((_stop&0x7) + 1))); \
} else { \
_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
while (++_startbyte < _stopbyte) \
_name[_startbyte] = 0; \
_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
} \
} while (0)
#define bit_nset(name, start, stop) do { \
bitstr_t *_name = (name); \
int _start = (start), _stop = (stop); \
int _startbyte = _bit_byte(_start); \
int _stopbyte = _bit_byte(_stop); \
if (_startbyte == _stopbyte) { \
_name[_startbyte] |= ((0xff << (_start&0x7)) & \
(0xff >> (7 - (_stop&0x7)))); \
} else { \
_name[_startbyte] |= 0xff << ((_start)&0x7); \
while (++_startbyte < _stopbyte) \
_name[_startbyte] = 0xff; \
_name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
} \
} while (0)
#define bit_ffc(name, nbits, value) do { \
bitstr_t *_name = (name); \
int _byte, _nbits = (nbits); \
int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
if (_nbits > 0) \
for (_byte = 0; _byte <= _stopbyte; ++_byte) \
if (_name[_byte] != 0xff) { \
bitstr_t _lb; \
_value = _byte << 3; \
for (_lb = _name[_byte]; (_lb&0x1); \
++_value, _lb >>= 1); \
break; \
} \
if (_value >= nbits) \
_value = -1; \
*(value) = _value; \
} while (0)
#define bit_ffs(name, nbits, value) do { \
bitstr_t *_name = (name); \
int _byte, _nbits = (nbits); \
int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
if (_nbits > 0) \
for (_byte = 0; _byte <= _stopbyte; ++_byte) \
if (_name[_byte]) { \
bitstr_t _lb; \
_value = _byte << 3; \
for (_lb = _name[_byte]; !(_lb&0x1); \
++_value, _lb >>= 1); \
break; \
} \
if (_value >= nbits) \
_value = -1; \
*(value) = _value; \
} while (0)
#endif