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

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} or float, float{2|3|4|8|16} as the type for the arguments unless otherwise stated.

Optionally, generic type name gentype may indicate double and double{2|3|4|8|16} as arguments and return values. If extended with cl_khr_fp16, generic type name gentype may indicate half and half{2|3|4|8|16} as arguments and return values.

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.

Specification

OpenCL Specification

Also see

Async Copy and Prefetch Functions, wait_group_events

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