Guidelines for Using Advanced PGO

When you use PGO, consider the following guidelines:

Minimize the changes to your program after instrumented execution and before feedback compilation. During feedback compilation, the compiler ignores dynamic information for functions modified after that information was generated.

Note
The compiler issues a warning that the dynamic information does not correspond to a modified function.

Repeat the instrumentation compilation if you make many changes to your source files after execution and before feedback compilation.
Specify the name of the profile summary file using the -prof_filefilename option

The options controlling advanced PGO optimizations are as follows.

Option	Description
-prof_dirdirname	Specifies the directory where .dyn files are to be created. The default is the directory where the program is compiled. The specified directory must already exist. You should specify the same -prof_dir option for both the instrumentation and feedback compilations. If you move the .dyn files, you need to specify the new path.
-prof_filefilename	Specifies file name for profiling summary file.