smp

Applies to C Applies to C++

Purpose

Enables parallelization of program code.

Syntax


Syntax Diagram

where:


auto Enables automatic parallelization and optimization of program code.
noauto Disables automatic parallelization of program code. Program code explicitly parallelized with SMP or OpenMP pragma statements is optimized.
opt Enables automatic parallelization and optimization of program code.
noopt Enables automatic parallelization, but disables optimization of parallelized program code. Use this setting when debugging parallelized program code.
omp Enables strict compliance to the OpenMP 2.0 standard. Automatic parallelization is disabled. Parallelized program code is optimized. Only OpenMP parallelization pragmas are recognized.
noomp Enables automatic parallelization and optimization of program code.
explicit Enables pragmas controlling explicit parallelization of loops.
noexplicit Disables pragmas controlling explicit parallelization of loops.
nested_par If specified, nested parallel constructs are not serialized. nested_par does not provide true nested parallelism because it does not cause new team of threads to be created for nested parallel regions. Instead, threads that are currently available are re-used.

This option should be used with caution. Depending on the number of threads available and the amount of work in an outer loop, inner loops could be executed sequentially even if this option is in effect. Parallelization overhead may not necessarily be offset by program performance gains.

nonested_par Disables parallization of nested parallel constructs.
rec_locks If specified, recursive locks are used, and nested critical sections will not cause a deadlock.
norec_locks If specified, recursive locks are not used.
schedule=sched_type[=n] Specifies what kind of scheduling algorithms and chunk size (n) are used for loops to which no other scheduling algorithm has been explicitly assigned in the source code. If sched_type is not specified, schedule=runtime is assumed for the default setting.

Notes

Related Concepts

Program Parallelization

Related Tasks

Control Parallel Processing with Pragmas

Related References

Compiler Command Line Options
O, optimize
threaded
Pragmas to Control Parallel Processing
Run-time Options for Parallel ProcessingOpenMP Run-time Options for Parallel Processing
Built-in Functions Used for Parallel Processing IBM Copyright 2003