c++ - 查询 CL_DEVICE_MAX_WORK_ITEM_SIZES

Question

我正在尝试在我的笔记本电脑上查询和输出 MAX Work ITEM SIZES。查询具有返回类型 size_t[]，如 here 所示

但是我仍然无法输出它。如何输出 MAX WORK ITEM SIZES？我是否正确声明了变量？

#include <iostream>
#include <vector>
#include <sstream>
using namespace std;

int main(void)
{
    vector<cl::Platform> platforms; // available platforms
    vector<cl::Device> devices;     // devices available to a platform
    string outputString;                // string for output
    VECTOR_CLASS<::size_t> maxWorkItem[3];  // for MAX_WORK_ITEM_SIZES
    unsigned int i, j;                      // counters

        cl::Platform::get(&platforms);

        // for each platform
        for (i = 0; i < platforms.size(); i++)
        {
            vector<cl::Device> devices; // available devices 

            //get all devices available to the platform
            platforms[i].getDevices(CL_DEVICE_TYPE_ALL, &devices);

            //for each device 
            for (j = 0; j < devices.size(); j++)
            {
                cl_device_type type;
                devices[j].getInfo(CL_DEVICE_TYPE, &type);

                if (type == CL_DEVICE_TYPE_CPU)
                {
                    platforms[i].getInfo(CL_PLATFORM_NAME, &outputString);
                    cout << "\tName of Platform: " << outputString << std::endl;

                    cout << "\tType: " << "CPU" << endl;


                    //Help here
                    maxWorkItem[0] = devices[j].getInfo<CL_DEVICE_MAX_WORK_ITEM_SIZES>();
                    cout << "\tMax Work Item Size: " << maxWorkItem[0] << endl;

                    cout << "--------------------------------------------------" << endl;

                }
            }
        }
}

Answer 1

您可以通过两种方式执行此操作，具体取决于您使用的 Device::getInfo() 重载。请注意，MAX WORK ITEM SIZES 为您提供了可以在工作组的每个维度中指定的最大工作项数:

1.

// ...
vector<size_t> maxWorkItem;
unsigned int i, j, k;

//...

        //Help here
        maxWorkItem = devices[j].getInfo<CL_DEVICE_MAX_WORK_ITEM_SIZES>();
        for (k = 0 ; k < maxWorkItem.size(); ++k)
        {
            cout << "\tMax Work Item Size (dim " << k << "): " << maxWorkItem[k] << endl;
        }
        cout << "--------------------------------------------------" << endl;

//...

2.

// ...
size_t maxWorkItem[3];
unsigned int i, j, k;

//...

        //Help here
        devices[j].getInfo(CL_DEVICE_MAX_WORK_ITEM_SIZES, &maxWorkItem);
        for (k = 0 ; k < 3; ++k)
        {
            cout << "\tMax Work Item Size (dim " << k << "): " << maxWorkItem[k] << endl;
        }
        cout << "--------------------------------------------------" << endl;

//...

检查 OpenCL C++ bindings documentation获取更多信息。