cl_khr_int64_base_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_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.

Function Description

long atom_add (__global long *p, long val)

long atom_add (__local long *p, long val)

ulong atom_add (__global ulong *p, ulong val)

ulong atom_add (__local ulong *p, ulong val)

Read the 64-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.

long atom_sub (__global long *p, long val)

long atom_sub (__local long *p, long val)

ulong atom_sub (__global ulong *p, ulong val)

ulong atom_sub (__local ulong *p, ulong val)

Read the 64-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.

long atom_xchg (__global long *p, long val)

long atom_xchg (__local long *p, long val)

ulong atom_xchg (__global ulong *p, ulong val)

ulong atom_xchg (__local ulong *p, ulong val)

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

long atom_inc (__global long *p)

long atom_inc (__local long *p)

ulong atom_inc (__global ulong *p)

ulong atom_inc (__local ulong *p)

Read the 64-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.

long atom_dec (__global long *p)

long atom_dec (__local long *p)

ulong atom_dec (__global ulong *p)

ulong atom_dec (__local ulong *p)

Read the 64-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.

long atom_cmpxchg (__global long *p, long cmp, long val)

long atom_cmpxchg (__local long *p, long cmp, long val)

ulong atom_cmpxchg (__global ulong *p, ulong cmp, ulong val)

ulong atom_cmpxchg (__local ulong *p, ulong cmp, ulong val)

Read the 64-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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