starpu-max/doc/doxygen/chapters/code/multiformat.c

#define NX 1024
struct point array_of_structs[NX];
starpu_data_handle_t handle;

/*
 * The conversion of a piece of data is itself a task, though it is created,
 * submitted and destroyed by StarPU internals and not by the user. Therefore,
 * we have to define two codelets.
 * Note that for now the conversion from the CPU format to the GPU format has to
 * be executed on the GPU, and the conversion from the GPU to the CPU has to be
 * executed on the CPU.
 */
#ifdef STARPU_USE_OPENCL
void cpu_to_opencl_opencl_func(void *buffers[], void *args);
struct starpu_codelet cpu_to_opencl_cl = {
    .where = STARPU_OPENCL,
    .opencl_funcs = { cpu_to_opencl_opencl_func, NULL },
    .nbuffers = 1,
    .modes = { STARPU_RW }
};

void opencl_to_cpu_func(void *buffers[], void *args);
struct starpu_codelet opencl_to_cpu_cl = {
    .where = STARPU_CPU,
    .cpu_funcs = { opencl_to_cpu_func, NULL },
    .nbuffers = 1,
    .modes = { STARPU_RW }
};
#endif

struct starpu_multiformat_data_interface_ops format_ops = {
#ifdef STARPU_USE_OPENCL
    .opencl_elemsize = 2 * sizeof(float),
    .cpu_to_opencl_cl = &cpu_to_opencl_cl,
    .opencl_to_cpu_cl = &opencl_to_cpu_cl,
#endif
    .cpu_elemsize = 2 * sizeof(float),
    ...
};

starpu_multiformat_data_register(handle, 0, &array_of_structs, NX, &format_ops);