/////  test the bandwidth of a device to host memcopy of a specific size///double testHostToDeviceTransfer(unsigned int memSize, accessMode accMode, memoryMode memMode){    double elapsedTimeInSec = 0.0;    double bandwidthInMBs = 0.0;    unsigned char* h_data = NULL;    cl_mem cmPinnedData = NULL;    cl_mem cmDevData = NULL;    cl_int ciErrNum = CL_SUCCESS;

    // Allocate and init host memory, pinned or conventional    if(memMode == PINNED)   {         // Create a host buffer        cmPinnedData = clCreateBuffer(cxGPUContext, CL_MEM_READ_WRITE | CL_MEM_ALLOC_HOST_PTR, memSize, NULL, &ciErrNum);        oclCheckError(ciErrNum, CL_SUCCESS);

        // Get a mapped pointer        h_data = (unsigned char*)clEnqueueMapBuffer(cqCommandQueue, cmPinnedData, CL_TRUE, CL_MAP_WRITE, 0, memSize, 0, NULL, NULL, &ciErrNum);        oclCheckError(ciErrNum, CL_SUCCESS);

        //initialize         for(unsigned int i = 0; i < memSize/sizeof(unsigned char); i++)        {            h_data[i] = (unsigned char)(i & 0xff);        }

        // unmap and make data in the host buffer valid        ciErrNum = clEnqueueUnmapMemObject(cqCommandQueue, cmPinnedData, (void*)h_data, 0, NULL, NULL);        oclCheckError(ciErrNum, CL_SUCCESS);        h_data = NULL;  // buffer is unmapped    }    else     {        // standard host alloc        h_data = (unsigned char *)malloc(memSize);

        //initialize         for(unsigned int i = 0; i < memSize/sizeof(unsigned char); i++)        {            h_data[i] = (unsigned char)(i & 0xff);        }    }

    // allocate device memory     cmDevData = clCreateBuffer(cxGPUContext, CL_MEM_READ_WRITE, memSize, NULL, &ciErrNum);    oclCheckError(ciErrNum, CL_SUCCESS);

    // Sync queue to host, start timer 0, and copy data from Host to GPU    clFinish(cqCommandQueue);    shrDeltaT(0);    if(accMode == DIRECT)    {         if(memMode == PINNED)         {            // Get a mapped pointer            h_data = (unsigned char*)clEnqueueMapBuffer(cqCommandQueue, cmPinnedData, CL_TRUE, CL_MAP_READ, 0, memSize, 0, NULL, NULL, &ciErrNum);            oclCheckError(ciErrNum, CL_SUCCESS);        }

        // DIRECT:  API access to device buffer         for(unsigned int i = 0; i < MEMCOPY_ITERATIONS; i++)        {                ciErrNum = clEnqueueWriteBuffer(cqCommandQueue, cmDevData, CL_FALSE, 0, memSize, h_data, 0, NULL, NULL);                oclCheckError(ciErrNum, CL_SUCCESS);        }        ciErrNum = clFinish(cqCommandQueue);        oclCheckError(ciErrNum, CL_SUCCESS);    }     else     {        // MAPPED: mapped pointers to device buffer and conventional pointer access        void* dm_idata = clEnqueueMapBuffer(cqCommandQueue, cmDevData, CL_TRUE, CL_MAP_WRITE, 0, memSize, 0, NULL, NULL, &ciErrNum);        oclCheckError(ciErrNum, CL_SUCCESS);        if(memMode == PINNED )         {            h_data = (unsigned char*)clEnqueueMapBuffer(cqCommandQueue, cmPinnedData, CL_TRUE, CL_MAP_READ, 0, memSize, 0, NULL, NULL, &ciErrNum);             oclCheckError(ciErrNum, CL_SUCCESS);         }         for(unsigned int i = 0; i < MEMCOPY_ITERATIONS; i++)        {            memcpy(dm_idata, h_data, memSize);        }        ciErrNum = clEnqueueUnmapMemObject(cqCommandQueue, cmDevData, dm_idata, 0, NULL, NULL);        oclCheckError(ciErrNum, CL_SUCCESS);    }

    //get the the elapsed time in seconds    elapsedTimeInSec = shrDeltaT(0);

    //calculate bandwidth in MB/s    bandwidthInMBs = ((double)memSize * (double)MEMCOPY_ITERATIONS)/(elapsedTimeInSec * (double)(1 << 20));

    //clean up memory    if(cmDevData)clReleaseMemObject(cmDevData);    if(cmPinnedData)     {        clEnqueueUnmapMemObject(cqCommandQueue, cmPinnedData, (void*)h_data, 0, NULL, NULL);        clReleaseMemObject(cmPinnedData);    }    h_data = NULL;

    return bandwidthInMBs;}/////  test the bandwidth of a device to host memcopy of a specific size///double testDeviceToDeviceTransfer(unsigned int memSize){    double elapsedTimeInSec = 0.0;    double bandwidthInMBs = 0.0;    unsigned char* h_idata = NULL;    cl_int ciErrNum = CL_SUCCESS;

    //allocate host memory    h_idata = (unsigned char *)malloc( memSize );

    //initialize the memory    for(unsigned int i = 0; i < memSize/sizeof(unsigned char); i++)    {        h_idata[i] = (unsigned char) (i & 0xff);    }

    // allocate device input and output memory and initialize the device input memory    cl_mem d_idata = clCreateBuffer(cxGPUContext, CL_MEM_READ_ONLY, memSize, NULL, &ciErrNum);    oclCheckError(ciErrNum, CL_SUCCESS);    cl_mem d_odata = clCreateBuffer(cxGPUContext, CL_MEM_WRITE_ONLY, memSize, NULL, &ciErrNum);             oclCheckError(ciErrNum, CL_SUCCESS);    ciErrNum = clEnqueueWriteBuffer(cqCommandQueue, d_idata, CL_TRUE, 0, memSize, h_idata, 0, NULL, NULL);    oclCheckError(ciErrNum, CL_SUCCESS);

    // Sync queue to host, start timer 0, and copy data from one GPU buffer to another GPU bufffer    clFinish(cqCommandQueue);    shrDeltaT(0);    for(unsigned int i = 0; i < MEMCOPY_ITERATIONS; i++)    {        ciErrNum = clEnqueueCopyBuffer(cqCommandQueue, d_idata, d_odata, 0, 0, memSize, 0, NULL, NULL);                        oclCheckError(ciErrNum, CL_SUCCESS);    }    

    // Sync with GPU    clFinish(cqCommandQueue);

    //get the the elapsed time in seconds    elapsedTimeInSec = shrDeltaT(0);

    // Calculate bandwidth in MB/s     //      This is for kernels that read and write GMEM simultaneously     //      Obtained Throughput for unidirectional block copies will be 1/2 of this #    bandwidthInMBs = 2.0 * ((double)memSize * (double)MEMCOPY_ITERATIONS)/(elapsedTimeInSec * (double)(1 << 20));

    //clean up memory on host and device    free(h_idata);    clReleaseMemObject(d_idata);    clReleaseMemObject(d_odata);

    return bandwidthInMBs;}