PGO Environment Variables

The following table describes environment values to determine the directory to store dynamic information files or whether to overwrite pgopti.dpi. Refer to your operating system documentation for instructions on how to specify environment values.

Profile-guided Optimization Environment Variables

Variable Description
PROF_DIR Specifies the directory in which dynamic information files are created. This variable applies to all three phases of the profiling process.
PROF_NO_CLOBBER Alters the feedback compilation phase slightly. By default, during the feedback compilation phase, the compiler merges the data from all dynamic information files and creates a new pgopti.dpi file if .dyn files are newer than an existing pgopti.dpi file. When this variable is set, the compiler does not overwrite the existing pgopti.dpi file. Instead, the compiler issues a warning and you must remove the pgopti.dpi file if you want to use additional dynamic information files.