Is my Java code being optimized by the JIT compiler?

How do you know whether a particular piece of code in your Java application is being compiled by the JIT compiler or not? JVM is a complicated runtime and it makes intelligent decisions about which code needs to go through the compilation pipeline, so it might happen that some classes and methods are not compiled or compiled by the less optimizing compilers.

On GraalVM the top tier JIT compiler is the GraalVM compiler and in this video I show how to enable the logging output to see whether methods of a given Java class have been compiled by it.

This is a simple trick and if you're evaluating GraalVM and would like to know whether some code is compiled by it, you can see that in no time.