/**
 * Implementation of FarmHash Fingerprint64, an open-source fingerprinting algorithm for strings.
 *
 * <p>Its speed is comparable to CityHash64, and its quality of hashing is at least as good.
 *
 * <p>Note to maintainers: This implementation relies on signed arithmetic being bit-wise equivalent
 * to unsigned arithmetic in all cases except:
 *
 * <ul>
 *   <li>comparisons (signed values can be negative)
 *   <li>division (avoided here)