The inline method which mitigates the overhead of a call of a method.
JIT forms into an inline what fulfills the following conditions.
- The IL code size is 16 bytes or less.
 - The branch command is not used (if sentence etc.).
 - The local variable is not used.
 - Exception handling has not been carried out (try, catch, etc.).
 - float is not used as the argument or return value of a method (probably by the Xbox 360, not applied).
 - When two or more arguments are in a method, it uses for the turn declared.
 
Reference
Higeneko diary