2.5.1  ICV Descriptions

The following ICVs store values that affect the operation of parallel regions.

• dyn-var - controls whether dynamic adjustment of the number of threads is enabled for encountered parallel regions. There is one copy of this ICV per data environment.
• nthreads-var - controls the number of threads requested for encountered parallel regions. There is one copy of this ICV per data environment.
• thread-limit-var - controls the maximum number of threads participating in the contention group. There is one copy of this ICV per data environment.
• max-active-levels-var - controls the maximum number of nested active parallel regions. There is one copy of this ICV per device.
• place-partition-var - controls the place partition available to the execution environment for encountered parallel regions. There is one copy of this ICV per implicit task.
• active-levels-var - the number of nested active parallel regions that enclose the current task such that all of the parallel regions are enclosed by the outermost initial task region on the current device. There is one copy of this ICV per data environment.
• levels-var - the number of nested parallel regions that enclose the current task such that all of the parallel regions are enclosed by the outermost initial task region on the current device. There is one copy of this ICV per data environment.
• bind-var - controls the binding of OpenMP threads to places. When binding is requested, the variable indicates that the execution environment is advised not to move threads between places. The variable can also provide default thread affinity policies. There is one copy of this ICV per data environment.

The following ICVs store values that affect the operation of worksharing-loop regions.

• run-sched-var - controls the schedule that is used for worksharing-loop regions when the runtime schedule kind is specified. There is one copy of this ICV per data environment.
• def-sched-var - controls the implementation defined default scheduling of worksharing-loop regions. There is one copy of this ICV per device.

The following ICVs store values that affect program execution.

• stacksize-var - controls the stack size for threads that the OpenMP implementation creates. There is one copy of this ICV per device.
• wait-policy-var - controls the desired behavior of waiting threads. There is one copy of this ICV per device.
• display-affinity-var - controls whether to display thread affinity. There is one copy of this ICV for the whole program.
• affinity-format-var - controls the thread affinity format when displaying thread affinity. There is one copy of this ICV per device.
• cancel-var - controls the desired behavior of the cancel construct and cancellation points. There is one copy of this ICV for the whole program.
• default-device-var - controls the default target device. There is one copy of this ICV per data environment.
• target-offload-var - controls the offloading behavior. There is one copy of this ICV for the whole program.
• max-task-priority-var - controls the maximum priority value that can be specified in the priority clause of the task construct. There is one copy of this ICV for the whole program.

The following ICVs store values that affect the operation of the OMPT tool interface.

• tool-var - controls whether an OpenMP implementation will try to register a tool. There is one copy of this ICV for the whole program.
• tool-libraries-var - specifies a list of absolute paths to tool libraries for OpenMP devices. There is one copy of this ICV for the whole program.

The following ICVs store values that affect the operation of the OMPD tool interface.

• debug-var - controls whether an OpenMP implementation will collect information that an OMPD library can access to satisfy requests from a tool. There is one copy of this ICV for the whole program.

The following ICVs store values that affect default memory allocation.

• def-allocator-var - controls the memory allocator to be used by memory allocation routines, directives and clauses when a memory allocator is not specified by the user. There is one copy of this ICV per implicit task.