Description

// Requires OpenCL C 3.0 or newer and both the __opencl_c_atomic_order_seq_cst
// and __opencl_c_atomic_scope_device features.
C atomic_load(volatile __global A *object)
C atomic_load(volatile __local A *object)

// Requires OpenCL C 2.0, or OpenCL C 3.0 or newer and all of the
// __opencl_c_generic_address_space, __opencl_c_atomic_order_seq_cst and
// __opencl_c_atomic_scope_device features.
C atomic_load(volatile A *object)

// Requires OpenCL C 3.0 or newer and the __opencl_c_atomic_scope_device
// feature.
C atomic_load_explicit(volatile __global A *object,
                       memory_order order)
C atomic_load_explicit(volatile __local A *object,
                       memory_order order)

// Requires OpenCL C 2.0, or OpenCL C 3.0 or newer and both the
// __opencl_c_generic_address_space and __opencl_c_atomic_scope_device
// features.
C atomic_load_explicit(volatile A *object,
                       memory_order order)

// Requires OpenCL C 3.0 or newer.
C atomic_load_explicit(volatile __global A *object,
                       memory_order order,
                       memory_scope scope)
C atomic_load_explicit(volatile __local A *object,
                       memory_order order,
                       memory_scope scope)

// Requires OpenCL C 2.0, or OpenCL C 3.0 or newer and the
// __opencl_c_generic_address_space feature.
C atomic_load_explicit(volatile A *object,
                       memory_order order,
                       memory_scope scope)

The order argument shall not be memory_order_release nor memory_order_acq_rel. Memory is affected according to the value of order. Atomically returns the value pointed to by object.

The non-explicit atomic_load function requires support for OpenCL C 2.0 or OpenCL C 3.0 or newer and both the __opencl_c_atomic_order_seq_cst and __opencl_c_atomic_scope_device features. For the explicit variants, memory order and scope enumerations must respect the restrictions section below.
The function variants that use the generic address space, i.e. no explicit address space is listed, require support for OpenCL C 2.0, or OpenCL C 3.0 or newer and the __opencl_c_generic_address_space feature.

See Also

atomicFunctions, atomicTypes, atomic_compare_exchange, atomic_exchange, atomic_fetch_key, atomic_flag, atomic_flag_clear, atomic_flag_test_and_set, atomic_flag_test_and_set_explicit, atomic_init, atomic_load, atomic_store, atomic_work_item_fence

Document Notes

For more information, see the OpenCL C Specification

This page is extracted from the OpenCL C Specification. Fixes and changes should be made to the Specification, not directly.

Copyright

Copyright 2014-2025 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0