Question

the question is in the title

Answer 1

Inlining is the responsibility of the CLR (JIT) and there are some conditions as to when a function is inlined:

1. The code size is smaller than 32 bytes of IL.
2. The function does not contain ‘complex’ constructs, e.g. loops, switch etc.
3. The function does not contain try/catch/finally.
4. The function is not declared as virtual.

As you will probably find out, 32 bytes is not very much in terms of code, it is suitable for quick and small if-else condition testing, property getters/setters. I don’t think you can gain any speed from inlining a bigger amount of code.