Scroll to navigation



cl_khr_int64_extended_atomics - Optional extensions that implement atomic operations on 64-bit signed and unsigned integers to locations in __global and __local memory.

#pragma OPENCL EXTENSION cl_khr_int64_extended_atomics : enable


An application that wants to use this extension will need to include the #pragma OPENCL EXTENSION cl_khr_int64_extended_atomics : enable directive in the OpenCL program source.

The atomic functions supported by the cl_khr_int64_extended_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_min(3clc) Compute min (old, val)
atom_max(3clc) Compute max (old, val)>
atom_and(3clc) Compute (old & val)
atom_or(3clc) Compute (old | val)
atom_xor(3clc) Compute (old ^ val)


OpenCL Specification[1]


EXTENSION(3clc), cl_khr_int64_base_atomics(3clc), atomicFunctions(3clc)


The Khronos Group


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.


OpenCL Specification
page 10, section 9.3 - 64-bit Atomics
01/14/2021 The Khronos Group