Bit Arrays

Compressed boolean arrays are useful to create memory efficient masks, so they are part of divERGe as static inline functions (i.e. only from the C interface). Documentation of all functions is found below:

static inline void bit_set(cbytes_t *b, cbit bit)

set bit number bit of byte b to one

static inline void bit_unset(cbytes_t *b, cbit bit)

set bit number bit of byte b to zero

static inline void bit_toggle(cbytes_t *b, cbit bit)

toggle bit number bit of byte b

static inline cbit bit_get(const cbytes_t *b, cbit bit)

get bit number bit of byte b

static inline size_t bitary_nwords(size_t nbit)

get number of bytes required to represent nbit contiguous bits in memory

static inline cbytes_t *bitary_alloc(size_t nbit)

allocate a bit array with at least nbit bits, all set to zero. The returnet memory must be free’d with free or diverge_mem_free().

static inline void bitary_set(cbytes_t *ary, size_t bitidx)

set the \(n\)-th bit (bitidx) of the bit array ary to one

static inline void bitary_unset(cbytes_t *ary, size_t bitidx)

set the \(n\)-th bit (bitidx) of the bit array ary to zero

static inline void bitary_toggle(cbytes_t *ary, size_t bitidx)

toggle the \(n\)-th bit (bitidx) of the bit array ary

static inline cbit bitary_get(const cbytes_t *ary, size_t bitidx)

get the \(n\)-th bit (bitidx) of the bit array ary

static inline void bitary_set_all(cbytes_t *ary, size_t nbit)

set the first nbit bits of the bit array ary to one

static inline void bitary_unset_all(cbytes_t *ary, size_t nbit)

set the first nbit bits of the bit array ary to zero

static inline void bitary_toggle_all(cbytes_t *ary, size_t nbit)

toggle the first nbit bits of the bit array ary

static inline size_t bitary_count(cbytes_t *ary, size_t nbit)

count the number of nonzero bits in ary, using fast __builtin_popcountll if available

static inline size_t bitary_count_parallel(cbytes_t *ary, size_t nbit, int nthr)

same as bitary_count() but with omp parallelization nthr-threaded