async_work_group_strided_copy

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

The OpenCL C programming language implements these functions that provide asynchronous copies between global and local memory and a prefetch from global memory.

Perform 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 dst_stride is the stride in elements for each gentype element written to dst. The async gather is performed by all work-items in a work-group

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.

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.

Notes

Returns an event object that can be used by wait_group_events to wait for the async copy to finish.

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

If extended with cl_khr_fp64, generic type name gentype may indicate double and double{2|4|8|16} as arguments and return values. If extended with cl_khr_fp16, generic type name gentype may indicate half and half{2|4|8|16} as arguments and return values.

Specification

OpenCL Specification

Also see

Async Copy and Prefetch Functions, wait_group_events

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