static long repeats_encode_64()

in lattices/lattice_utils.cpp [95:124]

• 29 lines of code
• 5 McCabe index (conditional complexity)

static long repeats_encode_64 (
     const std::vector<Repeat> & repeats,
     int dim, const float *c)
{
    uint64_t coded = 0;
    int nfree = dim;
    uint64_t code = 0, shift = 1;
    for (auto r = repeats.begin(); r != repeats.end(); ++r) {
        int rank = 0, occ = 0;
        uint64_t code_comb = 0;
        uint64_t tosee = ~coded;
        for(;;) {
            // directly jump to next available slot.
            int i = __builtin_ctzl(tosee);
            tosee &= ~(1UL << i) ;
            if (c[i] == r->val) {
                code_comb += comb(rank, occ + 1);
                occ++;
                coded |= 1UL << i;
                if (occ == r->n) break;
            }
            rank++;
        }
        uint64_t max_comb = comb(nfree, r->n);
        code += shift * code_comb;
        shift *= max_comb;
        nfree -= r->n;
    }
    return code;
}