bindbench will create many sockets and then bind them to port 0 (i.e.
tell the operating system to assign a free port to them).

Ideally, this should be a constant time operation, but some
implementations may implement selecting the smallest free port by
traversing a list or array.

On i386, bindbench will read the task cycle counter instead of
gettimeofday and give the results in CPU cycles, not usec.  You can
divide the numbers by the CPU frequency to get comparable numbers.  As
there is no portable way to get the CPU frequency, bindbench does not
even pretend to do this.