Prefetch bytes into the global cache.

void prefetch ( const __global gentype *p,
  size_t num_elements)


Prefetch num_elements * sizeof(gentype) bytes into the global cache. The prefetch instruction is applied to a work-item in a work-group and does not affect the functional behavior of the kernel.


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


OpenCL Specification

Also see

Async Copy and Prefetch Functions

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