That was the first thing that came to my mind as well. There are two definitions of what a hash function is, and they are almost always under specified. (1) Ma

That was the first thing that came to my mind as well. There are two definitions of what a hash function is, and they are almost always under specified. (1) Map key to an integer (2) Map key to a uniformly distributed integer In case of (1) the hash map implementation needs to do the mixing step, (2) is much better for benchmarking as in the article.