Are Java static calls more or less expensive than non-static calls?

Question

Is there any performance benefit one way or another? Is it compiler/VM specific? I am using Hotspot.

Answer 1

For the decision if a method should be static, the performance aspect should be irrelevant. If you have a performance problem, making lots of methods static isn't going to save the day. That said, static methods are almost certainly not slower than any instance method, in most cases marginally faster:

1.) Static methods are not polymorphic, so the JVM has less decisions to make to find the actual code to execute. This is a moot point in the Age of Hotspot, since Hotspot will optimize instance method calls that have only one implementation site, so they will perform the same.

2.) Another subtle difference is that static methods obviously have no "this" reference. This results in a stack frame one slot smaller than that of an instance method with the same signature and body ("this" is put in slot 0 of the local variables on the bytecode level, whereas for static methods slot 0 is used for the first parameter of the method).