Identify if memory_scope applies to work-items in a work-group or work-items of a kernel(s).



The OpenCL C programming language implements a subset of the C11 atomics (refer to section 7.17 of the C11 specification) and synchronization operations. These operations play a special role in making assignments in one work-item visible to another. A synchronization operation on one or more memory locations is either an acquire operation, a release operation, or both an acquire and release operation. (The C11 consume operation is not supported.) A synchronization operation without an associated memory location is a fence and can be either an acquire fence, a release fence or both an acquire and release fence. In addition, there are relaxed atomic operations, which are not synchronization operations, and atomic read-modify-write operations which have special characteristics

The enumerated type memory_scope specifies whether the memory ordering constraints given by memory_order apply to work-items in a work-group or work-items of a kernel(s) executing on the device or across devices (in the case of shared virtual memory). Its enumeration constants are as follows:


The memory_scope_work_item value for memory_scope can only be used with atomic_work_item_fence with flags set to CLK_IMAGE_MEM_FENCE.

The memory scope should only be used when performing atomic operations to global memory. Atomic operations to local memory only guarantee memory ordering in the work-group not across work-groups and therefore ignore the memory_scope value.



OpenCL Specification

Also see

Atomic Functions, memory_order

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