man cl_khr_int64_base_atomics (3): Optional extensions that implement atomic operations on 64-bit signed and unsigned integers to locations in __global and _

#pragma OPENCL EXTENSION cl_khr_int64_base_atomics : enable

DESCRIPTION

An application that wants to use this extension will need to include the #pragma OPENCL EXTENSION cl_khr_int64_base_atomics : enable directive in the OpenCL program source.

The atomic functions supported by the cl_khr_int64_base_atomics extension are described in the following table. All of the functions listed in the following table are performed in one atomic transaction.

These transactions are atomic for the device executing these atomic functions. There is no guarantee of atomicity if the atomic operations to the same memory location are being performed by kernels executing on multiple devices.

Atomic operations on 64-bit integers and 32-bit integers (and float) are also atomic w.r.t. each other.

Function	Description
atom_add(3clc)	Compute (old + val)
atom_sub(3clc)	Compute (old - val)
atom_xchg(3clc)	Swaps the 32-bit value (old) stored at location p with new value val.
atom_inc(3clc)	Compute (old + 1)
atom_dec(3clc)	Compute (old - 1)
atom_cmpxchg(3clc)	Compute (old == cmp) ? val : old

SPECIFICATION

m[blue]OpenCL Specificationm[][1]

AUTHORS

The Khronos Group

COPYRIGHT

Copyright © 2007-2011 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and/or associated documentation files (the "Materials"), to deal in the Materials without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Materials, and to permit persons to whom the Materials are furnished to do so, subject to the condition that this copyright notice and permission notice shall be included in all copies or substantial portions of the Materials.

NOTES

1.

OpenCL Specification