types of JIT in the CLR
转自：http://www.actionscript.org/forums/showthread.php3?t=182395
- Pre-JIT compiler:Pre-JIT compiles complete source code into native code in a single compilation cycle. This is done at the time of deployment of the application.， 它操作起来有点慢，但可以进行高级优化
- Econo JIT compiler: Econo-JIT compiles only those methods that are called at runtime. However, these compiled methods are removed when they are not required.，可进行快速编译，但生成的代码并非最优。当代码(如批处理文件中的脚本)可能被删除或重新生成时，这种编译器非常有用。
- 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 are stored in cache. When the same methods
are called again, the compiled code from cache is used for execution.