Used in profile-guided optimization to write all profile data from a running program to the PGC file.


pgosweep [options] image pgcfile


(Optional) The valid values for options are:

  • /? or /help displays the help message.

  • /reset resets counts to zero after sweep. This behavior is the default.

  • /pid:n only sweeps the specified PID, where n is the PID number.

  • /wait waits for the specified PID to terminate before collecting counts.

  • /onlyzero doesn't save a PGC file, only zero counts.

  • /pause pauses count collection on the system.

  • /resume resumes count collection on the system.

  • /noreset preserves the count in the runtime data structures.

The full path of an EXE or DLL file that was created by using the /GENPROFILE, /FASTGENPROFILE, or /LTCG:PGINSTRUMENT option.

The PGC file where this command writes out the data counts.


The pgosweep command works on programs that were built by using the /GENPROFILE or /FASTGENPROFILE option, or the deprecated /LTCG:PGINSTRUMENT option. It interrupts a running program and writes the profile data to a new PGC file. By default, the command resets counts after each write operation. If you specify the /noreset option, the command will record the values, but not reset them in the running program. This option gives you duplicate data if you retrieve the profile data later.

An alternative use for pgosweep is to retrieve profile information just for the normal operation of the application. For example, you could run pgosweep shortly after you start the application and discard that file. This command would remove profile data associated with startup costs. Then, you can run pgosweep before ending the application. Now the collected data has profile information only from the time the user could interact with the program.

When you name a PGC file (by using the pgcfile parameter) you can use the standard format, which is appname!n.pgc. The n represents an increasing numeric value for each file. If you use this format, the compiler automatically finds this data in the /LTCG /USEPROFILE or /LTCG:PGO phase. If you don't use the standard format, you must use pgomgr to merge the PGC files.


You can start this tool only from a Visual Studio developer command prompt. You can't start it from a system command prompt or from File Explorer.

For information on how to capture the profile data from within your executable, see PgoAutoSweep.


In this example command, pgosweep writes the current profile information for myapp.exe to myapp!1.pgc.

pgosweep myapp.exe myapp!1.pgc

See also

Profile-Guided Optimizations