// a mask with n set lo or hi bits
#define lomask(n) (uint32_t)((((uint32_t)1) << (n)) - 1)
#define himask(n) (~lomask(32 - n))
#define ONES32 ((uint32_t)0xffffffff)

#ifdef __INTEL_COMPILER
#define count_bits(b) _popcnt32(b)
#else
static inline uint32_t count_bits(uint32_t b)
{
    b = b - ((b >> 1) & 0x55555555);
    b = ((b >> 2) & 0x33333333) + (b & 0x33333333);
    b = ((b >> 4) + b) & 0x0f0f0f0f;
    b += (b >> 8);
    b += (b >> 16);
    return b & 0x3f;
    // here is the non-optimized version, for clarity:
    /*
    b = ((b>> 1)&0x55555555) + (b&0x55555555);
    b = ((b>> 2)&0x33333333) + (b&0x33333333);
    b = ((b>> 4)&0x0f0f0f0f) + (b&0x0f0f0f0f);
    b = ((b>> 8)&0x00ff00ff) + (b&0x00ff00ff);
    b = ((b>>16)&0x0000ffff) + (b&0x0000ffff);
    return b & 0x3f;
    */
}
#endif

uint32_t bitreverse(uint32_t x);

uint32_t *bitvector_new(uint64_t n, int initzero);
uint32_t *bitvector_resize(uint32_t *b, uint64_t oldsz, uint64_t newsz,
                           int initzero);
size_t bitvector_nwords(uint64_t nbits);
void bitvector_set(uint32_t *b, uint64_t n, uint32_t c);
uint32_t bitvector_get(uint32_t *b, uint64_t n);

uint32_t bitvector_next(uint32_t *b, uint64_t n0, uint64_t n);

void bitvector_shr(uint32_t *b, size_t n, uint32_t s);
void bitvector_shr_to(uint32_t *dest, uint32_t *b, size_t n, uint32_t s);
void bitvector_shl(uint32_t *b, size_t n, uint32_t s);
void bitvector_shl_to(uint32_t *dest, uint32_t *b, size_t n, uint32_t s,
                      bool_t scrap);
void bitvector_fill(uint32_t *b, uint32_t offs, uint32_t c, uint32_t nbits);
void bitvector_copy(uint32_t *dest, uint32_t doffs, uint32_t *a,
                    uint32_t aoffs, uint32_t nbits);
void bitvector_not(uint32_t *b, uint32_t offs, uint32_t nbits);
void bitvector_not_to(uint32_t *dest, uint32_t doffs, uint32_t *a,
                      uint32_t aoffs, uint32_t nbits);
void bitvector_reverse(uint32_t *b, uint32_t offs, uint32_t nbits);
void bitvector_reverse_to(uint32_t *dest, uint32_t *src, uint32_t soffs,
                          uint32_t nbits);
void bitvector_and_to(uint32_t *dest, uint32_t doffs, uint32_t *a,
                      uint32_t aoffs, uint32_t *b, uint32_t boffs,
                      uint32_t nbits);
void bitvector_or_to(uint32_t *dest, uint32_t doffs, uint32_t *a,
                     uint32_t aoffs, uint32_t *b, uint32_t boffs,
                     uint32_t nbits);
void bitvector_xor_to(uint32_t *dest, uint32_t doffs, uint32_t *a,
                      uint32_t aoffs, uint32_t *b, uint32_t boffs,
                      uint32_t nbits);
uint64_t bitvector_count(uint32_t *b, uint32_t offs, uint64_t nbits);
uint32_t bitvector_any0(uint32_t *b, uint32_t offs, uint32_t nbits);
uint32_t bitvector_any1(uint32_t *b, uint32_t offs, uint32_t nbits);