As the docu in kprofilemethod.h says:

 Those macros help profiling using QTime.
 They allow to sum up the time taken by a given bit of code
 in a method called several times.
 This way one can find out which low-level method used by a high-level
 method is taking most of its time.

WARNING:

 Please do not commit code that uses kprofilemethod.h
 Since not everyone has tdesdk installed, it won't build for everyone.
 This is a tool to be used for a one-time profiling, and then you need
 to remove all its traces before committing.

TODO:

 KDevelop, XEmacs and vi shortcuts to insert begin/end macros around a block
 of code (e.g. after selecting it) - this macro would also insert the
 int variable, and another shortcut for inserting the print macro.