presto-spi/src/main/java/io/prestosql/spi/block/MapHashTables.java/MapHashTables/computePosition
class MapHashTables:    static int computePosition(long hashcode, int hashTableSize)
    {
        return (int) ((Integer.toUnsignedLong(Long.hashCode(hashcode)) * hashTableSize) >> 32);
    }