This option creates multiple processes that can be used
to compile large numbers of source files at the same time. It can improve
performance by reducing the time it takes to compile source files on the
This option causes the compiler to create one or more
copies of itself, each in a separate process. These copies simultaneously
compile the source files.
is not specified
for this option, the default value is as follows:
On Windows* systems, the value is based on the
setting of the NUMBER_OF_PROCESSORS environment variable.
systems, the value is 2.
This option applies to compilations, but not to linking
or link-time code generation.