Best way of message passing from GameLoop (Main loop) on iPhone

Does excessive message passing (function calling) from a game Loop which is scheduled at 60 Hz make game performance worse? In开发者_开发知识库 my gameLoop a lot of work needs to be performed. So which is the better way: writing everything in GameLoop function or splitting the work into several function and then calling them from gameLoop?

Personally I think the best advice is to go for the clearest implementation, i.e., separating your code. If you have performance issues, then profile to find the culprits - which will be much easier if your code is clear and then optimise.