The bytecode is then executed by the Java Virtual Machine (JVM). JVMs today use a technique called Just-in-Time (JIT) compilation to produce native instructions that the system’s CPU can execute.

A change to Java’s G1 garbage collector would lower the memory and processing overhead and speed the execution of Java’s C2 optimizing JIT (just-in-time) compiler, benefiting cloud deployments ...

It is Java’s JIT (Just-In-Time) compilation capabilities that still are barred from iOS units, Stahl says.

Two things that developers are often concerned about with Java deployment is the garbage collector and the start-up speed of the JIT compiler. Zing is using Azul’s C4 concurrent garbage collector.

Just-in-time (JIT) compilers tend to have different requirements. Getting LLVM to handle these needs was part of the contributions that Azul delivered to the LLVM project.