Function bitstring

src/e9patch/e9mapping.cpp:87–109

 */
template <typename Key>
static void bitstring(Key key, std::string &str)
{
    Key mask = 0xFFFFFFFFFFFFFFFFull;
    for (unsigned i = 0; i < size(key); i += 2 * 64)
    {
        const char digs[] = "0123456789ABCDEF";
        size_t count = 0;
        for (unsigned j = 0; j < 2; j++)
        {
            uint64_t key64 = (key & mask).to_ullong();
            count += __builtin_popcountll(key64);
            key >>= 64;
        }
        switch (count)
        {
            case 0: case 1:
                break;
            default:
                count = 1 + (count - 2) / 9; break;
        }
        str += digs[count];
    }
}
template <>
void bitstring<Key128>(Key128 key, std::string &str)
{