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head/sys/sys/bitstring.h
| Show First 20 Lines • Show All 269 Lines • ▼ Show 20 Lines | |||||
| /* Find the first bit clear in bit string. */ | /* Find the first bit clear in bit string. */ | ||||
| static inline void | static inline void | ||||
| bit_ffc(bitstr_t *_bitstr, int _nbits, int *_result) | bit_ffc(bitstr_t *_bitstr, int _nbits, int *_result) | ||||
| { | { | ||||
| bit_ffc_at(_bitstr, /*start*/0, _nbits, _result); | bit_ffc_at(_bitstr, /*start*/0, _nbits, _result); | ||||
| } | } | ||||
| /* Find contiguous sequence of at least size set bits at or after start */ | |||||
| static inline void | |||||
| bit_ffs_area_at(bitstr_t *_bitstr, int _start, int _nbits, int _size, int *_result) | |||||
| { | |||||
| int _index, _end, _i; | |||||
| again: | |||||
| /* Find the first set bit */ | |||||
| bit_ffs_at(_bitstr, _start, _nbits, &_index); | |||||
| if (_index < 0) { | |||||
| *_result = -1; | |||||
| return; | |||||
| } | |||||
| /* Make sure there is enough room left in the bitstr */ | |||||
| _end = _index + _size; | |||||
| if (_end > _nbits) { | |||||
| *_result = -1; | |||||
| return; | |||||
| } | |||||
| /* Find the next cleared bit starting at _index, stopping at _end */ | |||||
| bit_ffc_at(_bitstr, _index, _end, &_i); | |||||
| if (_i >= 0) { | |||||
| /* we found a clear bit between _index and _end, so skip ahead | |||||
| * to the next bit and try again | |||||
| */ | |||||
| _start = _i + 1; | |||||
| goto again; | |||||
| } | |||||
| *_result = _index; | |||||
| } | |||||
| /* Find contiguous sequence of at least size cleared bits at or after start */ | |||||
| static inline void | |||||
| bit_ffc_area_at(bitstr_t *_bitstr, int _start, int _nbits, int _size, int *_result) | |||||
| { | |||||
| int _index, _end, _i; | |||||
| again: | |||||
| /* Find the first zero bit */ | |||||
| bit_ffc_at(_bitstr, _start, _nbits, &_index); | |||||
| if (_index < 0) { | |||||
| *_result = -1; | |||||
| return; | |||||
| } | |||||
| /* Make sure there is enough room left in the bitstr */ | |||||
| _end = _index + _size; | |||||
| if (_end > _nbits) { | |||||
| *_result = -1; | |||||
| return; | |||||
| } | |||||
| /* Find the next set bit starting at _index, stopping at _end */ | |||||
| bit_ffs_at(_bitstr, _index, _end, &_i); | |||||
| if (_i >= 0) { | |||||
| /* we found a set bit between _index and _end, so skip ahead | |||||
| * to the next bit and try again | |||||
| */ | |||||
| _start = _i + 1; | |||||
| goto again; | |||||
| } | |||||
| *_result = _index; | |||||
| } | |||||
| /* Find contiguous sequence of at least size set bits in bit string */ | |||||
| static inline void | |||||
| bit_ffs_area(bitstr_t *_bitstr, int _nbits, int _size, int *_result) | |||||
| { | |||||
| bit_ffs_area_at(_bitstr, /*start*/0, _nbits, _size, _result); | |||||
| } | |||||
| /* Find contiguous sequence of at least size cleared bits in bit string */ | |||||
| static inline void | |||||
| bit_ffc_area(bitstr_t *_bitstr, int _nbits, int _size, int *_result) | |||||
| { | |||||
| bit_ffc_area_at(_bitstr, /*start*/0, _nbits, _size, _result); | |||||
| } | |||||
| /* Count the number of bits set in a bitstr of size _nbits at or after _start */ | /* Count the number of bits set in a bitstr of size _nbits at or after _start */ | ||||
| static inline void | static inline void | ||||
| bit_count(bitstr_t *_bitstr, int _start, int _nbits, int *_result) | bit_count(bitstr_t *_bitstr, int _start, int _nbits, int *_result) | ||||
| { | { | ||||
| bitstr_t *_curbitstr, mask; | bitstr_t *_curbitstr, mask; | ||||
| int _value = 0, curbitstr_len; | int _value = 0, curbitstr_len; | ||||
| if (_start >= _nbits) | if (_start >= _nbits) | ||||
| Show All 29 Lines | |||||