oneAPI Construction Kit supports fetching and building the Khronos OpenCL ICD Loader when the variable CA_CL_ENABLE_ICD_LOADER is set to ON. Support is disabled by default but can be enabled when configuring the build.
Warning
When the OpenCL ICD Loader is enabled and OpenCL drivers are installed on
the system, failure to explicitly specify either OCL_ICD_FILENAMES
or OCL_ICD_VENDORS when running a test suite or application will
result in it using the system driver rather than a driver from the
oneAPI Construction Kit build.
Hint
Note that on windows it will be necessary to set the registry setting to the built bin/CL.ll. The source/cl/tools/icd-register.ps1 can be used for this.
During development, when the OpenCL ICD Loader is enabled, executables which link against it must specify an Installable Client Driver (ICD) which implements the OpenCL API.
- OCL_ICD_FILENAMES
An environment variable containing a
:separated list of ICD’s. If present, it is parsed by the OpenCL ICD Loader and used to populate the list of OpenCL drivers available to an OpenCL application. Example:$ OCL_ICD_FILENAMES=/path/to/libCL.so /path/to/UnitCL
oneAPI Construction Kit also supports the creation of .icd files which
are output to <build>/share/OpenCL/vendors and can be read by the
OpenCL ICD Loader to populate the list of OpenCL drivers for an
application to choose from.
- OCL_ICD_VENDORS
An environment variable specifying the directory to search for
.icdfiles. If present, the OpenCL ICD Loader uses it to override the default search path of/etc/OpenCL/vendorson Linux or the registry entryHKEY_LOCAL_MACHINE\SOFTWARE\Khronos\OpenCL\Vendorson Windows. For example:$ OCL_ICD_VENDORS=/path/to/OpenCL/vendors /path/to/UnitCL
Note
The oneAPI Construction Kit check target infrastructure automatically
makes use of the OpenCL ICD Loader when enabled, selecting the CL
OpenCL driver by specifying OCL_ICD_FILENAMES.
