For years we’ve been told that the JVM’s amazing optimizers can take your running code and make i...
For years we’ve been told that the JVM’s amazing optimizers can take your running code and make it “fast” or “as fast as C++” or “as fast as C”…or sometimes “faster than C”. And yet we don’t often see this happen in practice, due in large part to (good and bad) development patterns that have taken hold in the Java world.
In this talk, we’ll explore the main reasons why Java code rarely runs as fast as C or C++ and how you can write really bad Java code that the JVM will do a better job of optimizing. We’ll take some popular microbenchmarks and burn them to the ground, monitoring JIT logs and assembly dumps along the way.