Using profile-directed feedback

You can use profile-directed feedback (PDF) to tune the performance of your application for a typical usage scenario. The compiler optimizes the application based on an analysis of how often branches are taken and blocks of code are run.

Use the PDF process as one of the last steps of optimization before you put the application into production. Optimization at all levels from -O2 up can benefit from PDF. Other optimizations such as the -qipa option and optimization levels -O4 and -O5 can also benefit from PDF process.

The following diagram illustrates the PDF process.