Is it just me, or does that loop not do anything?
Anyway, to answer your question: blindingly fast. Each operation will execute so fast you could blink and not see it happen
Think about it: you're asking us to tell you how fast a particular loop runs on any unknown PC. Perhaps you could instead ask something quantified and important like "realistically, can I call hashCode() more than 1 million times every 1 ms on a modern PC?". Or something like "are there any performance problems with Arraylists with 5000 elements?" (to which the answer is YES!: be a little careful about add's, and especially careful about indexOf's and remove's, which can be slow on mor than a few thousand elements)
OTOH, how many times do people have to say "optimize last" and "profile before optimizing"?
The question "this code is responsible for 65% of my runtime, which I can't explain at all" then that would be a very good question for people to help with. As it stands, it's a little hard to see how it could even show up at all in your profiler...