None.
Prepares the object files produced by the compiler for profiling.
The compiler produces monitoring code that counts the number of times each routine is called. The compiler inserts a call to the monitor subroutine at the start of each subprogram.
Not applicable.
When you run a program compiled with -p or -pg and it ends normally, it produces a gmon.out file with the profiling information. You can then use the gprof command to generate a runtime profile.
$ xlf95 -pg needs_tuning.f
$ a.out
$ gprof
.
.
.
detailed and verbose profiling data
.
.
.