What really happens to your Java code along the way to becoming machine code?

Red Hat has been developing an almost pauseless GC for OpenJDK which requires adding read barriers to every object access. We've also developed ARM64 versions of both the server and the client compilers. This has given us quite a bit of experience with the internals of the various methods of generating machine code inside the JVM. This talk will start with a brief tour of the various levels of code generation available and then open up the floor for questions from our panel.