memory_scope
Identify if memory_scope applies to work-items in a work-group or work-items of a kernel(s).
Description
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:
(if cl_khr_subgroups is supported)memory_scope_work_item
memory_scope_work_group
memory_scope_device
memory_scope_all_svm_devices
memory_scope_sub_group
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.
If the
cl_khr_subgroups
extension is enabled, The memory_scope_sub_group
specifies that the memory ordering constraints given by memory_order
apply to work-items in a sub-group. This memory scope can be used
when performing atomic operations to global or local memory.
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