-autopar

Enable automatic loop parallelization.

SPARC: 77/90

Finds and parallelizes appropriate loops for running in parallel on multiple processors. Analyzes loops for inter-iteration data dependencies and loop restructuring. If the optimization level is not specified -O3 or higher, it will automatically be raised to -O3.

-g cancels -autopar. Debugging is facilitated by specifying -g without any optimization or parallelization options since not all debugging features are available when these options are invoked. See the dbx documentation for details.

To improve performance, also specify the -stackvar option when using any of the parallelization options, including -autopar.

Avoid -autopar if the program already contains explicit calls to the libthread threads library. See note with -mt on "-mt".

The -autopar option is not appropriate on a single-processor system, and the compiled code will generally run slower.

To run a parallelized program on a multiprocessor system, you must set the PARALLEL environment variable prior to execution. The default is 1. However, do not request more processors than are available.

If you use -autopar and compile and link in one step, the microtasking library and the threads-safe Fortran runtime library will automatically be linked. If you use -autopar and compile and link in separate steps, then you must also link with -autopar to insure linking the appropriate libraries.

Other parallelization options are -parallel and -explicitpar. Also, the -reduction option may be used with -autopar.

Refer to the Fortran Programming Guide for more information on parallelization.