Performs an async gather of num_elements gentype elements from source to destination.

event_t async_work_group_strided_copy(__local gentype *dst,
                                      const __global gentype *src,
                                      size_t num_gentypes,
                                      size_t src_stride,
                                      event_t event)

event_t async_work_group_strided_copy(__global gentype *dst,
                                      const __local gentype *src,
                                      size_t num_gentypes,
                                      size_t dst_stride,
                                      event_t event)

Description

async_work_group_strided_copy performs an async gather of num_gentypes gentype elements from src to dst. The src_stride is the stride in elements for each gentype element read from src. The async gather is performed by all work-items in a work-group and this built-in function must therefore be encountered by all work-items in a work-group executing the kernel with the same argument values; otherwise the results are undefined. This rule applies to ND-ranges implemented with uniform and non-uniform work-groups.

Returns an event object that can be used by wait_group_events to wait for the async copy to finish. The event argument can also be used to associate the async_work_group_strided_copy with a previous async copy allowing an event to be shared by multiple async copies; otherwise event should be zero.

If event argument is non-zero, the event object supplied in event argument will be returned.

This function does not perform any implicit synchronization of source data such as using a barrier before performing the copy.

The behavior of async_work_group_strided_copy is undefined if src_stride or dst_stride is 0, or if the src_stride or dst_stride values cause the src or dst pointers to exceed the upper bounds of the address space during the copy.

General information about async copy functions: The generic type name gentype indicates the built-in data types char, char{2|3|4|8|16}, uchar, uchar{2|3|4|8|16}, short, short{2|3|4|8|16}, ushort, ushort{2|3|4|8|16}, int, int{2|3|4|8|16}, uint, uint{2|3|4|8|16}, long, long{2|3|4|8|16}, ulong, ulong{2|3|4|8|16}, float, float{2|3|4|8|16}, or double, double{2|3|4|8|16} as the type for the arguments unless otherwise stated.

When extended by the cl_khr_fp16 extension, the generic type gentypen is extended to include half, half2, half3, half4, half8, and half16.

Notes

async_work_group_copy and async_work_group_strided_copy for 3-component vector types behave as async_work_group_copy and async_work_group_strided_copy respectively for 4-component vector types.

Also see

Specification