suggest places where you might try to eliminate function calls that use a lot of time. *Note The Call Graph: Call Graph. The "annotated source" listing is a copy of the program's source code, labeled with the number of times each line of the program was executed. *Note The Annotated Source Listing: Annotated Source. To better understand how profiling works, you may wish to read a description of its implementation. *Note Implementation of Profiling: Implementation.