The .Net languages use its corresponding runtime
to run the application on different Operating Systems. During the code
execution time, the Managed Code compiled only when it is needed, that is it
converts the appropriate instructions to the native code for execution just
before when each function is called. This process is called Just In Time (JIT)
compilation, also known as Dynamic Translation. With the help of Just In Time Compiler (JIT) the Common Language Runtime (CLR) doing these
The Common Language Runtime (CLR) provides
various Just In Time compilers (JIT) and each works on a different
architecture depending on Operating System. That is why the same Microsoft
Intermediate Language (MSIL) can be executed on different Operating Systems
without rewrite the source code. Just In Time (JIT) compilation
preserves memory and save time during application initialization.
JIT compiler is a part of the runtime execution
environment. In Microsoft .NET there are three types of JIT compilers:
· Pre-JIT: - Pre-JIT compiles complete source code into native code in a
compilation cycle. This is done at the time of deployment of the application.
· Econo-JIT: - Econo-JIT compiles only those methods that are called at
However, these compiled methods are removed when they are not required.
· Normal-JIT: - Normal-JIT compiles
only those methods that are called at
runtime.These methods are compiled the first time they are called, and then they
stored in cache. When the same methods are called again, the compiled code
cache is used for execution.