By viewing the source code of a function identified in the VTune analyzer as a hotspots, you can see the statistics associated with lines of source code.
The VTune analyzer cannot measure statistics for each and every line of code. Doing so would basically hang the system, that is, it would be unresponsive, because of the overhead. The whole point of sampling is to allow the system to run at near full speed, just as it will when executing your code under normal circumstances.
By viewing the annotated source code, you can determine which sections of a function are impacting performance. Typically, you will want to collect samples based on processor events other than Clockticks, once you have identified the hotspot function(s). This will help you to determine why the code is a hotspot. See the Tuning Assistant and the online help for info on common coding pitfall events and primary/secondary tuning events.