openCL-矩陣相乘

這是AMD異構大賽發的書上的例子，我自己加了一些東西，實現了一下。不過還沒有學會如何分析啟動並執行時間，先貼上代碼

這是第一次用amd APP KernelAnalyzer感覺還可以吧，

simpleMultiply.cl

// Enter your kernel in this window__kernel                                         void simpleMultiply(__global float* outPutC,             int widthA,                                   int heightA,                                     int widthB ,                                     int heightB ,                                     __global float* inputA ,                        __global  float* inputB                           )                                               {                                                   int row = get_global_id(1);                       int col = get_global_id(0);                         float sum = 0.0f  ;                                for(int i=0;i<widthA; i++)                        {                                                      sum += inputA[row*widthA+i] * inputB[i*widthB+col];     }                                               outPutC[row*widthB+col] = sum;                        } ;              

main.cpp

/*   項目：openCL的矩陣相乘   作者：劉榮   時間：2012.11.20*/#include <iostream>#include<time.h>#include <string> #include<math.h>#include <vector>#include <CL/cl.h>#include <fstream>using namespace std;//kernel函數std::stringconvertToString(const char *filename)//將kernel源碼，即自己寫的並行化的函數，轉化成字串{    size_t size;    char*  str;    std::string s;    std::fstream f(filename, (std::fstream::in | std::fstream::binary));    if(f.is_open())    {        size_t fileSize;        f.seekg(0, std::fstream::end);        size = fileSize = (size_t)f.tellg();        f.seekg(0, std::fstream::beg);        str = new char[size+1];        if(!str)        {            f.close();            std::cout << "Memory allocation failed";            return NULL;        }        f.read(str, fileSize);        f.close();        str[size] = '\0';            s = str;        delete[] str;        return s;    }    else    {        std::cout << "\nFile containg the kernel code(\".cl\") not found. Please copy the required file in the folder containg the executable.\n";        exit(1);    }    return NULL;}int main(){double start,end,time1,time2;//查詢平台cl_int ciErrNum;cl_platform_id platform;ciErrNum = clGetPlatformIDs(1, &platform, NULL);if(ciErrNum != CL_SUCCESS){cout<<"擷取裝置失敗"<<endl;return 0;}//擷取裝置資訊cl_device_id device;cl_int   status;    cl_uint maxDims;    cl_event events[2];    size_t globalThreads[1];    size_t localThreads[1];    size_t maxWorkGroupSize;    size_t maxWorkItemSizes[3];    ////////////////////////////////////////////////////////////////////     // STEP 7 Analyzing proper workgroup size for the kernel    //          by querying device information    //    7.1 Device Info CL_DEVICE_MAX_WORK_GROUP_SIZE    //    7.2 Device Info CL_DEVICE_MAX_WORK_ITEM_DIMENSIONS    //    7.3 Device Info CL_DEVICE_MAX_WORK_ITEM_SIZES    ////////////////////////////////////////////////////////////////////             /**    * Query device capabilities. Maximum     * work item dimensions and the maximmum    * work item sizes    */ ciErrNum = clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL, 1, &device, NULL);    status = clGetDeviceInfo(        device,         CL_DEVICE_MAX_WORK_GROUP_SIZE,         sizeof(size_t),         (void*)&maxWorkGroupSize,         NULL);    if(status != CL_SUCCESS)     {          std::cout << "Error: Getting Device Info. (clGetDeviceInfo)\n";        return 0;    }        status = clGetDeviceInfo(        device,         CL_DEVICE_MAX_WORK_ITEM_DIMENSIONS,         sizeof(cl_uint),         (void*)&maxDims,         NULL);    if(status != CL_SUCCESS)     {          std::cout << "Error: Getting Device Info. (clGetDeviceInfo)\n";        return 0;    }    status = clGetDeviceInfo(        device,         CL_DEVICE_MAX_WORK_ITEM_SIZES,         sizeof(size_t)*maxDims,        (void*)maxWorkItemSizes,        NULL);    if(status != CL_SUCCESS)     {          std::cout << "Error: Getting Device Info. (clGetDeviceInfo)\n";        return 0;    }cout<<"maxWorkItemSizes"<<maxWorkItemSizes<<endl;cout<<"maxDims"<<maxDims<<endl;cout<<"maxWorkGroupSize"<<(int)maxWorkGroupSize<<endl;//建立上下文cl_context_properties cps[3] = {CL_CONTEXT_PLATFORM, (cl_context_properties)platform, 0};cl_context ctx = clCreateContext(cps, 1, &device, NULL, NULL, &ciErrNum);if(ciErrNum != CL_SUCCESS){cout<<"建立上下文失敗"<<endl;return 0;}cl_command_queue myqueue = clCreateCommandQueue(ctx,device,0,&ciErrNum);if(ciErrNum != CL_SUCCESS){cout<<"命令隊列失敗"<<endl;return 0;}//聲明buffer,傳輸資料float *A = NULL; // 輸入數組float *B = NULL; // 輸入數組float *C = NULL; // 輸出數組int wA=20,hA=20;int wB=20,hB=20;int wC=20,hC=20;// 數組的大小const int  elementsA = wA*hA;const int  elementsB = wB*hB;const int  elementsC = hA*wB;// 計算記憶體大小size_t datasizeA = sizeof(float)*elementsA;size_t datasizeB = sizeof(float)*elementsB;size_t datasizeC = sizeof(float)*elementsC;// 分配記憶體空間A = (float*)malloc(datasizeA);B = (float*)malloc(datasizeB);C = (float*)malloc(datasizeC);// 初始化輸入數組for(int i = 0;i < elementsA;i++){A[i] = std::rand()/1.5;//B[i] = std::rand()/1.5;}for(int i = 0;i < elementsB;i++){B[i] = std::rand()/1.5;//B[i] = std::rand()/1.5;}cl_mem bufferA = clCreateBuffer(ctx,CL_MEM_READ_ONLY,wA*hA*sizeof(float),NULL,&ciErrNum);ciErrNum = clEnqueueWriteBuffer(myqueue,bufferA,CL_TRUE,0,wA*hA*sizeof(float),(void*)A,0,NULL,NULL);cl_mem bufferB = clCreateBuffer(ctx,CL_MEM_READ_ONLY,wB*hB*sizeof(float),NULL,&ciErrNum);ciErrNum = clEnqueueWriteBuffer(myqueue,bufferB,CL_TRUE,0,wB*hB*sizeof(float),(void*)B,0,NULL,NULL);cl_mem bufferC = clCreateBuffer(ctx,CL_MEM_WRITE_ONLY,hA*wB*sizeof(float),NULL,&ciErrNum);//運行時kernel編譯const char * filename  = "simpleMultiply.cl";    std::string  sourceStr = convertToString(filename);    const char * source    = sourceStr.c_str();    size_t sourceSize[]    = { strlen(source) };//直接將CL檔案讀到記憶體    cl_program myprog = clCreateProgramWithSource(                  ctx,                   1,                   &source,                  sourceSize,                  &ciErrNum);//cl_program myprog = clCreateProgramWithSource(ctx,1,(const char**)&programSource,NULL,&ciErrNum);ciErrNum = clBuildProgram(myprog,0,NULL,NULL,NULL,NULL);cl_kernel mykernel = clCreateKernel(myprog,"simpleMultiply",&ciErrNum);//運行程式clSetKernelArg(mykernel,0,sizeof(cl_mem),(void*)&bufferC);clSetKernelArg(mykernel,1,sizeof(cl_mem),(void*)&wA);clSetKernelArg(mykernel,2,sizeof(cl_mem),(void*)&hA);clSetKernelArg(mykernel,3,sizeof(cl_mem),(void*)&wB);clSetKernelArg(mykernel,4,sizeof(cl_mem),(void*)&hB);clSetKernelArg(mykernel,5,sizeof(cl_mem),(void*)&bufferA);clSetKernelArg(mykernel,6,sizeof(cl_mem),(void*)&bufferB);size_t localws[2] ={20,20};size_t globalws[2]={wC,hC};////start = clock();ciErrNum = clEnqueueNDRangeKernel(myqueue,mykernel,2,NULL,globalws,localws,0,NULL,&events[0]);//時間同步status = clWaitForEvents(1, &events[0]);    if(status != CL_SUCCESS)     {         std::cout <<            "Error: Waiting for kernel run to finish. \            (clWaitForEvents)\n";        return 0;    }    status = clReleaseEvent(events[0]);//將結果拷貝到主機端end = clock();time1=end-start;cout<<"shijian "<<time1<<endl;ciErrNum = clEnqueueReadBuffer(myqueue,bufferC,CL_TRUE,0,wC*hC*sizeof(float),(void*)C,0,NULL,&events[1]);status = clWaitForEvents(1, &events[1]);    if(status != CL_SUCCESS)     {         std::cout <<            "Error: Waiting for read buffer call to finish. \            (clWaitForEvents)\n";        return 0;    }        status = clReleaseEvent(events[1]);    if(status != CL_SUCCESS)     {         std::cout <<            "Error: Release event object. \            (clReleaseEvent)\n";        return 0;    }//return 0;}