Add a quick test code to detect available OpenCL platforms.

Compile this with clew files from source/core/opencl/clcc.

Change-Id: I9a0be046ec996a6bccdcc8555aa8119fcf9afde3

sc/workben/opencl/platform_detect.cxx

+#include <cstdlib>
+#include <iostream>
+#include <vector>
+#include <string>
+
+#include "clew.h"
+
+using namespace std;
+
+int main()
+{
+    const char* dllname = "OpenCL.dll"; // from GPU driver.
+//  const char* dllname = "amdocl.dll"; // from AMD SDK
+//  const char* dllname = "intelocl.dll"; // from Intel SDK
+    int status = clewInit(dllname);
+    if (status < 0)
+    {
+        cout << "failed to load" << endl;
+        return EXIT_FAILURE;
+    }
+
+    cout << "OpenCL.dll loaded successfully." << endl;
+
+    cl_uint platformCount = 0;
+    clGetPlatformIDs(0, NULL, &platformCount);
+
+    cout << "number of platforms: " << platformCount << endl;
+    vector<cl_platform_id> platformIDs(platformCount);
+    if (clGetPlatformIDs(platformCount, &platformIDs[0], NULL) != CL_SUCCESS)
+    {
+        cout << "failed to get platform IDs" << endl;
+        return EXIT_FAILURE;
+    }
+
+    for (size_t i = 0, n = platformIDs.size(); i < n; ++i)
+    {
+        cout << "* platform (ID=" << platformIDs[i] << ")" << endl;
+        string param(100, '\0');
+        if (clGetPlatformInfo(platformIDs[i], CL_PLATFORM_PROFILE, param.size(), &param[0], NULL) == CL_SUCCESS)
+            cout << "  profile: " << param.c_str() << endl;
+        if (clGetPlatformInfo(platformIDs[i], CL_PLATFORM_VERSION, param.size(), &param[0], NULL) == CL_SUCCESS)
+            cout << "  version: " << param.c_str() << endl;
+        if (clGetPlatformInfo(platformIDs[i], CL_PLATFORM_NAME, param.size(), &param[0], NULL) == CL_SUCCESS)
+            cout << "  name: " << param.c_str() << endl;
+        if (clGetPlatformInfo(platformIDs[i], CL_PLATFORM_VENDOR, param.size(), &param[0], NULL) == CL_SUCCESS)
+            cout << "  vendor: " << param.c_str() << endl;
+        if (clGetPlatformInfo(platformIDs[i], CL_PLATFORM_EXTENSIONS, param.size(), &param[0], NULL) == CL_SUCCESS)
+            cout << "  extensions: " << param.c_str() << endl;
+
+        cl_uint deviceCount = 0;
+        clGetDeviceIDs(platformIDs[i], CL_DEVICE_TYPE_ALL, 0, NULL, &deviceCount);
+        cout << "  number of devices: " << deviceCount << endl;
+
+        vector<cl_device_id> deviceIDs(deviceCount);
+        if (clGetDeviceIDs(platformIDs[i], CL_DEVICE_TYPE_ALL, deviceCount, &deviceIDs[0], NULL) != CL_SUCCESS)
+            continue;
+
+        for (size_t j = 0; j < deviceIDs.size(); ++j)
+        {
+            cout << "  * device (ID=" << deviceIDs[j] << ")" << endl;
+            if (clGetDeviceInfo(deviceIDs[j], CL_DEVICE_VENDOR, param.size(), &param[0], NULL) == CL_SUCCESS)
+                cout << "    vendor: " << param.c_str() << endl;
+            if (clGetDeviceInfo(deviceIDs[j], CL_DEVICE_VERSION, param.size(), &param[0], NULL) == CL_SUCCESS)
+                cout << "    version: " << param.c_str() << endl;
+            if (clGetDeviceInfo(deviceIDs[j], CL_DRIVER_VERSION, param.size(), &param[0], NULL) == CL_SUCCESS)
+                cout << "    driver version: " << param.c_str() << endl;
+        }
+    }
+
+    return EXIT_SUCCESS;
+}