C++ command_queue::get_device方法代码示例

inline void test_fill(T v1, T v2, T v3, bc::command_queue queue) {
    if(boost::is_same<typename bc::scalar_type<T>::type, bc::double_>::value &&
       !queue.get_device().supports_extension("cl_khr_fp64")) {
        std::cerr << "Skipping test_fill<" << bc::type_name<T>() << ">() "
                     "on device which doesn't support cl_khr_fp64" << std::endl;
        return;
    }

    bc::vector<T> vector(4, queue.get_context());
    bc::fill(vector.begin(), vector.end(), v1, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v1, v1, v1, v1));

    vector.resize(1000, queue);
    bc::fill(vector.begin(), vector.end(), v2, queue);
    queue.finish();
    BOOST_CHECK_EQUAL(vector.front(), v2);
    BOOST_CHECK_EQUAL(vector.back(), v2);

    bc::fill(vector.begin() + 500, vector.end(), v3, queue);
    queue.finish();
    BOOST_CHECK_EQUAL(vector.front(), v2);
    BOOST_CHECK_EQUAL(vector[499], v2);
    BOOST_CHECK_EQUAL(vector[500], v3);
    BOOST_CHECK_EQUAL(vector.back(), v3);
}

inline void test_fill_n(T v1, T v2, T v3, bc::command_queue queue) {
    if(boost::is_same<typename bc::scalar_type<T>::type, bc::double_>::value &&
       !queue.get_device().supports_extension("cl_khr_fp64")) {
        std::cerr << "Skipping test_fill_n<" << bc::type_name<T>() << ">() "
                     "on device which doesn't support cl_khr_fp64" << std::endl;
        return;
    }

    bc::vector<T> vector(4, queue.get_context());
    bc::fill_n(vector.begin(), 4, v1, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v1, v1, v1, v1));

    bc::fill_n(vector.begin(), 3, v2, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v2, v2, v2, v1));

    bc::fill_n(vector.begin() + 1, 2, v3, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v2, v3, v3, v1));

    bc::fill_n(vector.begin(), 4, v2, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v2, v2, v2, v2));

    // fill last element
    bc::fill_n(vector.end() - 1, 1, v3, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v2, v2, v2, v3));

    // fill first element
    bc::fill_n(vector.begin(), 1, v1, queue);
    queue.finish();
    CHECK_RANGE_EQUAL(T, 4, vector, (v1, v2, v2, v3));
}

        /// Select best launch configuration for the given shared memory requirements.
        void config(const boost::compute::command_queue &queue, std::function<size_t(size_t)> smem) {
            boost::compute::device dev = queue.get_device();

            size_t ws;

            if ( is_cpu(queue) ) {
                ws = 1;
            } else {
                // Select workgroup size that would fit into the device.
                ws = dev.get_info<std::vector<size_t>>(CL_DEVICE_MAX_WORK_ITEM_SIZES)[0] / 2;

                size_t max_ws   = max_threads_per_block(queue);
                size_t max_smem = max_shared_memory_per_block(queue);

                // Reduce workgroup size until it satisfies resource requirements:
                while( (ws > max_ws) || (smem(ws) > max_smem) )
                    ws /= 2;
            }

            config(num_workgroups(queue), ws);
        }

void tune_accumulate(const compute::vector<T>& data,
                     const size_t trials,
                     compute::command_queue& queue)
{
    boost::shared_ptr<compute::detail::parameter_cache>
        params = compute::detail::parameter_cache::get_global_cache(queue.get_device());

    const std::string cache_key =
        std::string("__boost_reduce_on_gpu_") + compute::type_name<T>();

    const compute::uint_ tpbs[] = { 4, 8, 16, 32, 64, 128, 256, 512, 1024 };
    const compute::uint_ vpts[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };

    double min_time = std::numeric_limits<double>::max();
    compute::uint_ best_tpb = 0;
    compute::uint_ best_vpt = 0;

    for(size_t i = 0; i < sizeof(tpbs) / sizeof(*tpbs); i++){
        params->set(cache_key, "tpb", tpbs[i]);
        for(size_t j = 0; j < sizeof(vpts) / sizeof(*vpts); j++){
            params->set(cache_key, "vpt", vpts[j]);

            try {
                const double t = perf_accumulate(data, trials, queue);
                if(t < min_time){
                    best_tpb = tpbs[i];
                    best_vpt = vpts[j];
                    min_time = t;
                }
            }
            catch(compute::opencl_error&){
                // invalid parameters for this device, skip
            }
        }
    }

    // store optimal parameters
    params->set(cache_key, "tpb", best_tpb);
    params->set(cache_key, "vpt", best_vpt);
}

 size_t preferred_work_group_size_multiple(const boost::compute::command_queue &q) const {
     return K.get_work_group_info<size_t>(q.get_device(), CL_KERNEL_PREFERRED_WORK_GROUP_SIZE_MULTIPLE);
 }

        /// The size in bytes of shared memory per block available for this kernel.
        size_t max_shared_memory_per_block(const boost::compute::command_queue &q) const {
            boost::compute::device d = q.get_device();

            return d.local_memory_size() - K.get_work_group_info<cl_ulong>(d, CL_KERNEL_LOCAL_MEM_SIZE);
        }

 /// The maximum number of threads per block, beyond which a launch of the kernel would fail.
 size_t max_threads_per_block(const boost::compute::command_queue &q) const {
     return K.get_work_group_info<size_t>(q.get_device(), CL_KERNEL_WORK_GROUP_SIZE);
 }

 /// Standard number of workgroups to launch on a device.
 static inline size_t num_workgroups(const boost::compute::command_queue &q) {
     // This is a simple heuristic-based estimate. More advanced technique may
     // be employed later.
     return 8 * q.get_device().compute_units();
 }