Fortran wrapper library providing OpenCL functionality. It uses (and includes) the "clFortran" interface code available from https://github.com/cass-support/clfortran.
The Makefile picks-up the compiler, flags etc. from environment variables. You will need to set F90 (and optionally, F90FLAGS). At link time you will need to link with the OpenCL run-time libraries on your system.
There are 3 environment variables to control the OpenCL execution at runtime:
-
FORTCL_KERNELS_FILE: Allows to specify at run-time the binary or source code filename containing the OpenCL kernels to execute. -
FORTCL_PLATFORM: Integer that selects in which OpenCL platform the kernels are going to be executed. The list of OpenCL platforms is a 1-based indexing list that can be queried with theclinfocommand. If this variable is not set, the kernels will be launched on platform 1 (first available). -
FORTCL_VERBOSE: Boolean value to request more verbose information of the OpenCL runtime execution. It is considered true if this environment variable exists and is set to a value other than 0.
There are three examples in the examples directory but in short:
program fcl_test
implicit none
use iso_c_binding, only: c_intptr_t
use fortcl
character(len=*) :: filename = "/my/compiled/kernels.aocx"
integer(c_intptr_t), target :: device_buffer
! Initialise the OpenCL device and environment
call ocl_env_init()
! Load a kernel (it can be a source file or a pre-compiled object)
call add_kernels(1, "my_ocl_kernel", filename)
! Create a read-write buffer on the device
device_buffer = create_rw_buffer(num_bytes)
! ...
! OpenCL-specific code here to set kernel arguments and
! launch kernel.
! ...
! Clean up
call ocl_release()
end program fcl_test