cl_khr_global_int32_base_atomics

Optional extensions that implement atomic operations on 32-bit signed and unsigned integers to locations in __global memory.

#pragma OPENCL EXTENSION cl_khr_global_int32_base_atomics : enable

Description

An application that wants to use this extension will need to include the #pragma OPENCL EXTENSION cl_khr_global_int32_base_atomics : enable directive in the OpenCL program source.

The atomic functions supported by the cl_khr_global_int32_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.

Function Description

int atom_add (__global int *p, int val)

unsigned int atom_add (__global unsigned int *p,
          unsigned int val)

 Read the 32-bit value (referred to as old) stored at location pointed by p. Compute (old + val) and store result at location pointed by p. The function returns old.

int atom_sub (__global int *p, int val)

unsigned int atom_sub (__global unsigned int *p,
          unsigned int val)

 Read the 32-bit value (referred to as old) stored at location pointed by p. Compute (old - val) and store result at location pointed by p. The function returns old.

int atom_xchg (__global int *p, int val)

unsigned int atom_xchg (__global unsigned int *p,
          unsigned int val)

 Swaps the old value stored at location p with new value given by val). Returns old value.

int atom_inc (__global int *p)

unsigned int atom_inc (__global unsigned int *p)

 Read the 32-bit value (referred to as old) stored at location pointed by p. Compute (old + 1) and store result at location pointed by p. The function returns old.

int atom_dec (__global int *p)

unsigned int atom_dec (__global unsigned int *p)

 Read the 32-bit value (referred to as old) stored at location pointed by p. Compute (old - 1) and store result at location pointed by p. The function returns old.

int atom_cmpxchg (__global int *p, intcmp, int val)

unsigned int atom_cmpxchg (__global unsigned int *p,
          unsigned int cmp,
          unsigned int val)

 Read the 32-bit value (referred to as old) stored at location pointed by p. Compute (old == cmp) ? val : old and store result at location pointed by p. The function returns old.

Specification

OpenCL Specification

Also see

EXTENSION

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