....... if a function calls make the statements of the program jump and that jump makes the program slower compare to straight execution of statements from top to bottom. Just wondering :D
What if the function were thousands of lines and called from hundreds of places?
Would you want the code insertion done every place it was called? That would result in massive program bloat; all to save one jump instruction which is infinitesimal compared to the code inserted.
What if the inserted function also had hundreds of function calls? Would you want those expanded inline also?