Returns the address of the extension function named by funcname.

clGetExtensionFunctionAddress (  funcname)



Name of an extension function.


The macro clGetExtensionFunctionAddress returns the address of the extension function named by funcname. The pointer returned should be cast to a function pointer type matching the extension function's definition defined in the appropriate extension specification and header file. A return value of NULL indicates that the specified function does not exist for the implementation. A non-NULL return value for clGetExtensionFunctionAddress does not guarantee that an extension function is actually supported. The application must also make a corresponding query using clGetPlatformInfo(platform, CL_PLATFORM_EXTENSIONS, ... ) or clGetDeviceInfo(device, CL_DEVICE_EXTENSIONS, ... ) to determine if an extension is supported by the OpenCL implementation.

clGetExtensionFunctionAddress may not be queried for core (non-extension) functions in OpenCL. For functions that are queryable with clGetExtensionFunctionAddress, implementations may choose to also export those functions statically from the object libraries implementing those functions. However, portable applications cannot rely on this behavior.


Since there is no way to qualify the query with a device, the function pointer returned must work for all implementations of that extension on different devices. The behavior of calling a device extension function on a device not supporting that extension is undefined.


OpenCL Specification

Also see


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