Profile-based optimization should be enabled during the final stages of application development. C Compile for instrumentation. The -c option in the first command line suppresses linking and creates an intermediate object file called sample.o . The .o file can be used later in the optimization phase, avoiding a second compile. The second command line uses the -o option to link sample.o into sample.exe .
Instrumented programs run slower than non-instrumented programs.
Only use instrumented code to collect statistics for profile-based optimization. C Create intermediate file for instrumentation. This step creates and logs the profile statistics to a file, by default called flow.data . The data collection file is a structured file that may be used to store the statistics from multiple test runs of different programs that you may have instrumented. Maintaining Profile Data Files Profile-based optimization stores execution profile data in a disk file.