-xautopar

(SPARC) Turns on automatic parallelization for multiple processors. Does dependence analysis (analyze loops for inter-iteration data dependence) and loop restructuring. If optimization is not at -xO3 or higher, optimization is raised to -xO3 and a warning is emitted.

Avoid -xautopar if you do your own thread management.

The Sun Workshop includes the license required to use multiprocessor C. To get faster execution, this option requires a multiple processor system. On a single-processor system, the resulting binary usually runs slower.

To determine how many processors you have, use the psrinfo command:

% psrinfo
0	on-line			since 01/12/95 10:41:54
1	on-line			since 01/12/95 10:41:54
2	on-line			since 01/12/95 10:41:54
3	on-line			since 01/12/95 10:41:54

To request a number of processors, set the PARALLEL environment variable. The default is 1.

• Do not request more processors than are available.

• If N is the number of processors on the machine, then for a one-user, multiprocessor system, try PARALLEL=N-1.

If you use -xautopar and compile and link in one step, then linking automatically includes the microtasking library and the threads-safe C runtime library. If you use -xautopar and compile and link in separate steps, then you must also link with -xautopar.