Tips to Encourage PGO

Consider the following when using PGO:

• 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.
• Repeat the instrumentation compilation if you make many changes to your source files after execution and before feedback compilation.
• PGO is most effective when you can properly define a representative workload.
• Use PGO on applications with many functions, calls, or branches that are not loop-bound.
  Examples:
• Databases,
• Decision-support (enterprise),
• MCAD Apps with computation spread throughout;
• not confined to kernels

You can run PGO on different workloads. You can use the results in these ways:

• merged by the compiler to produce a general-purpose binary
• separately—use each workload to generate a special-purpose binary optimized for that workload