---
name: "atomic_xchg"
section: "3clc"
platform: "linux"
package: "opencl-1.2-man-doc"
version: "1.0~svn33624-5.1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/atomic_xchg"
---

# atomic\_xchg(3clc)

atomic\_xchg functions.

## NAME

atomic\_xchg - atomic\_xchg functions.

##

**int atomic\_xchg(volatile global(3clc) int \****p***, int** *val***);**

**unsigned int atomic\_xchg(volatile global(3clc) unsigned int \****p***, unsigned int** *val***);**

**float atomic\_xchg(volatile global(3clc) float \****p***, float** *val***);**

**int atomic\_xchg(volatile local(3clc) int \****p***, int** *val***);**

**unsigned int atomic\_xchg(volatile local(3clc) unsigned int \****p***, unsigned int** *val***);**

**float atomic\_xchg(volatile global(3clc) float \****p***, float** *val***);**

## DESCRIPTION

Swaps the *old* value stored at location *p* with new value given by *val*. The function returns *old*.

A 64-bit version of this function, [**atom\_xchg**(3clc)](/atom_xchg/3clc.md), is enabled by [**cl\_khr\_int64\_base\_atomics**(3clc)](/cl_khr_int64_base_atomics/3clc.md).

## SPECIFICATION

**OpenCL Specification**\[1\]

## SEE ALSO

[**atomicFunctions**(3clc)](/atomicFunctions/3clc.md), [**atom\_xchg**(3clc)](/atom_xchg/3clc.md)

## 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

  page 279, section 6.12.11 - Atomic Functions for 32-bit integers