prof-gen, Qprof-gen

Produces an instrumented object file that can be used in profile guided optimization.

IDE Equivalent

Windows: General > Profile Guided Optimization

General > Code Coverage Build Options

Linux: None

OS X: None

Architectures

IA-32, Intel® 64 architecture

Syntax

Linux and OS X:

-prof-gen[=keyword]

-no-prof-gen

Windows:

/Qprof-gen[:keyword]

/Qprof-gen-

Arguments

keyword

Specifies details for the instrumented file. Possible values are:

default	Produces an instrumented object file. This is the same as specifying -prof-gen (LinuxOS and OS X) or /Qprof-gen (Windows* OS) with no keyword.
srcpos	Produces an instrumented object file that includes extra source position information.
globdata	Produces an instrumented object file that includes information for global data layout.

Default

-no-prof-gen or /Qprof-gen-

Profile generation is disabled.

Description

This option produces an instrumented object file that can be used in profile guided optimization. It gets the execution count of each basic block.

If you specify keyword srcpos or globdata, a static profile information file (.spi) is created. These settings may increase the time needed to do a parallel build using -prof-gen, because of contention writing the .spi file.

These options are used in phase 1 of the Profile Guided Optimizer (PGO) to instruct the compiler to produce instrumented code in your object files in preparation for instrumented execution.

When option -prof-gen (Linux* OS and OS X*) or /Qprof-gen (Windows* OS) is used to produce an instrumented binary file for profile generation, some optimizations are disabled. Those optimizations are not disabled for any subsequent profile-guided compilation with option -prof-use (Linux* OS and OS X*) or /Qprof-use (Windows* OS) that makes use of the generated profiles.

Alternate Options

None