How to track php functions/codes duration of processing

I am developing a browser based game and i'd like to know which functions take the most time to process and so on.

Does a开发者_如何学运维nyone of you guys know what I can start with ? Using PHP 5.3

It sounds like you want xhprof. It excels at profiling.

There's a profiler in XDebug.

There's also one called PHP APD