Example #1
0
func (this *kernel) EnqueueNDRange(queue CommandQueue,
	work_dim cl.CL_uint,
	global_work_offset []cl.CL_size_t,
	global_work_size []cl.CL_size_t,
	local_work_size []cl.CL_size_t,
	event_wait_list []Event) (Event, error) {
	var errCode cl.CL_int
	var event_id cl.CL_event

	numEvents := cl.CL_uint(len(event_wait_list))

	var events []cl.CL_event

	if numEvents > 0 {
		events = make([]cl.CL_event, numEvents)
		for i := cl.CL_uint(0); i < numEvents; i++ {
			events[i] = event_wait_list[i].GetID()
		}
	}

	if errCode = cl.CLEnqueueNDRangeKernel(queue.GetID(),
		this.kernel_id,
		work_dim,
		global_work_offset,
		global_work_size,
		local_work_size,
		numEvents,
		events,
		&event_id); errCode != cl.CL_SUCCESS {
		return nil, fmt.Errorf("EnqueueNDRange failure with errcode_ret %d: %s", errCode, cl.ERROR_CODES_STRINGS[-errCode])
	} else {
		return &event{event_id}, nil
	}
}
Example #2
0
File: bst.go Project: xfong/gocl
func main() {
	// Use this to check the output of each API call
	var status cl.CL_int

	//-----------------------------------------------------
	// STEP 1: Discover and initialize the platforms
	//-----------------------------------------------------
	var numPlatforms cl.CL_uint
	var platforms []cl.CL_platform_id

	// Use clGetPlatformIDs() to retrieve the number of
	// platforms
	status = cl.CLGetPlatformIDs(0, nil, &numPlatforms)

	// Allocate enough space for each platform
	platforms = make([]cl.CL_platform_id, numPlatforms)

	// Fill in platforms with clGetPlatformIDs()
	status = cl.CLGetPlatformIDs(numPlatforms, platforms, nil)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetPlatformIDs")

	//-----------------------------------------------------
	// STEP 2: Discover and initialize the GPU devices
	//-----------------------------------------------------
	var numDevices cl.CL_uint
	var devices []cl.CL_device_id

	// Use clGetDeviceIDs() to retrieve the number of
	// devices present
	status = cl.CLGetDeviceIDs(platforms[0],
		cl.CL_DEVICE_TYPE_GPU,
		0,
		nil,
		&numDevices)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetDeviceIDs")

	// Allocate enough space for each device
	devices = make([]cl.CL_device_id, numDevices)

	// Fill in devices with clGetDeviceIDs()
	status = cl.CLGetDeviceIDs(platforms[0],
		cl.CL_DEVICE_TYPE_GPU,
		numDevices,
		devices,
		nil)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetDeviceIDs")

	//-----------------------------------------------------
	// STEP 3: Create a context
	//-----------------------------------------------------
	var context cl.CL_context

	// Create a context using clCreateContext() and
	// associate it with the devices
	context = cl.CLCreateContext(nil,
		numDevices,
		devices,
		nil,
		nil,
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateContext")
	defer cl.CLReleaseContext(context)

	//-----------------------------------------------------
	// STEP 4: Create a command queue
	//-----------------------------------------------------
	var cmdQueue cl.CL_command_queue

	// Create a command queue using clCreateCommandQueueWithProperties(),
	// and associate it with the device you want to execute
	cmdQueue = cl.CLCreateCommandQueueWithProperties(context,
		devices[0],
		nil,
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateCommandQueueWithProperties")
	defer cl.CLReleaseCommandQueue(cmdQueue)

	//-----------------------------------------------------
	// STEP 5: Create device buffers
	//-----------------------------------------------------
	// initialize any device/SVM memory here.

	/* svm buffer for binary tree */
	svmTreeBuf := cl.CLSVMAlloc(context,
		cl.CL_MEM_READ_WRITE,
		cl.CL_size_t(NUMBER_OF_NODES*unsafe.Sizeof(sampleNode)),
		0)
	if nil == svmTreeBuf {
		println("clSVMAlloc(svmTreeBuf) failed.")
		return
	}
	defer cl.CLSVMFree(context, svmTreeBuf)

	/* svm buffer for search keys */
	svmSearchBuf := cl.CLSVMAlloc(context,
		cl.CL_MEM_READ_WRITE,
		cl.CL_size_t(NUMBER_OF_SEARCH_KEY*unsafe.Sizeof(sampleKey)),
		0)
	if nil == svmSearchBuf {
		println("clSVMAlloc(svmSearchBuf) failed.")
		return
	}
	defer cl.CLSVMFree(context, svmSearchBuf)

	//create the binary tree and set the root
	/* root node of the binary tree */
	svmRoot := cpuCreateBinaryTree(cmdQueue, svmTreeBuf)

	//initialize search keys
	cpuInitSearchKeys(cmdQueue, svmSearchBuf)

	/* if voice is not deliberately muzzled, shout parameters */
	fmt.Printf("-------------------------------------------------------------------------\n")
	fmt.Printf("Searching %d keys in a BST having %d Nodes...\n", NUMBER_OF_SEARCH_KEY, NUMBER_OF_NODES)
	fmt.Printf("-------------------------------------------------------------------------\n")

	//-----------------------------------------------------
	// STEP 6: Create and compile the program
	//-----------------------------------------------------
	programSource, programeSize := utils.Load_programsource("bst.cl")

	// Create a program using clCreateProgramWithSource()
	program := cl.CLCreateProgramWithSource(context,
		1,
		programSource[:],
		programeSize[:],
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateProgramWithSource")
	defer cl.CLReleaseProgram(program)

	// Build (compile) the program for the devices with
	// clBuildProgram()
	options := "-cl-std=CL2.0"
	status = cl.CLBuildProgram(program,
		numDevices,
		devices,
		[]byte(options),
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		var program_log interface{}
		var log_size cl.CL_size_t

		/* Find size of log and print to std output */
		cl.CLGetProgramBuildInfo(program, devices[0], cl.CL_PROGRAM_BUILD_LOG,
			0, nil, &log_size)
		cl.CLGetProgramBuildInfo(program, devices[0], cl.CL_PROGRAM_BUILD_LOG,
			log_size, &program_log, nil)
		fmt.Printf("%s\n", program_log)
		return
	}
	//utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLBuildProgram")

	//-----------------------------------------------------
	// STEP 7: Create the kernel
	//-----------------------------------------------------
	var kernel cl.CL_kernel

	// Use clCreateKernel() to create a kernel
	kernel = cl.CLCreateKernel(program, []byte("bst_kernel"), &status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateKernel")
	defer cl.CLReleaseKernel(kernel)

	//-----------------------------------------------------
	// STEP 8: Set the kernel arguments
	//-----------------------------------------------------
	// Associate the input and output buffers with the
	// kernel
	// using clSetKernelArg()
	// Set appropriate arguments to the kernel
	status = cl.CLSetKernelArgSVMPointer(kernel,
		0,
		svmTreeBuf)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArgSVMPointer(svmTreeBuf)")

	status = cl.CLSetKernelArgSVMPointer(kernel,
		1,
		svmSearchBuf)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArgSVMPointer(svmSearchBuf)")

	//-----------------------------------------------------
	// STEP 9: Configure the work-item structure
	//-----------------------------------------------------
	// Define an index space (global work size) of work
	// items for
	// execution. A workgroup size (local work size) is not
	// required,
	// but can be used.
	var localWorkSize [1]cl.CL_size_t
	var kernelWorkGroupSize interface{}
	status = cl.CLGetKernelWorkGroupInfo(kernel,
		devices[0],
		cl.CL_KERNEL_WORK_GROUP_SIZE,
		cl.CL_size_t(unsafe.Sizeof(localWorkSize[0])),
		&kernelWorkGroupSize,
		nil)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetKernelWorkGroupInfo")
	localWorkSize[0] = kernelWorkGroupSize.(cl.CL_size_t)

	var globalWorkSize [1]cl.CL_size_t
	globalWorkSize[0] = NUMBER_OF_SEARCH_KEY

	//-----------------------------------------------------
	// STEP 10: Enqueue the kernel for execution
	//-----------------------------------------------------
	// Execute the kernel by using
	// clEnqueueNDRangeKernel().
	// 'globalWorkSize' is the 1D dimension of the
	// work-items
	status = cl.CLEnqueueNDRangeKernel(cmdQueue,
		kernel,
		1,
		nil,
		globalWorkSize[:],
		localWorkSize[:],
		0,
		nil,
		nil)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLEnqueueNDRangeKernel")

	status = cl.CLFlush(cmdQueue)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clFlush")

	status = cl.CLFinish(cmdQueue)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clFinish")

	//-----------------------------------------------------
	// STEP 11: Read the output buffer back to the host
	//-----------------------------------------------------
	// Use clEnqueueReadBuffer() to read the OpenCL output
	// buffer (bufferC)
	// to the host output array (C)
	//copy the data back to host buffer

	//this demo doesn't need clEnqueueReadBuffer due to SVM

	//-----------------------------------------------------
	// STEP 12: Verify the results
	//-----------------------------------------------------
	// reference implementation
	svmBinaryTreeCPUReference(cmdQueue,
		svmRoot,
		svmTreeBuf,
		svmSearchBuf)

	// compare the results and see if they match
	pass := svmCompareResults(cmdQueue, svmSearchBuf)
	if pass {
		println("Passed!")
	} else {
		println("Failed!")
	}
}
Example #3
0
File: pipe.go Project: xfong/gocl
func main() {
	// Use this to check the output of each API call
	var status cl.CL_int

	//-----------------------------------------------------
	// STEP 1: Discover and initialize the platforms
	//-----------------------------------------------------
	var numPlatforms cl.CL_uint
	var platforms []cl.CL_platform_id

	// Use clGetPlatformIDs() to retrieve the number of
	// platforms
	status = cl.CLGetPlatformIDs(0, nil, &numPlatforms)

	// Allocate enough space for each platform
	platforms = make([]cl.CL_platform_id, numPlatforms)

	// Fill in platforms with clGetPlatformIDs()
	status = cl.CLGetPlatformIDs(numPlatforms, platforms, nil)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetPlatformIDs")

	//-----------------------------------------------------
	// STEP 2: Discover and initialize the GPU devices
	//-----------------------------------------------------
	var numDevices cl.CL_uint
	var devices []cl.CL_device_id

	// Use clGetDeviceIDs() to retrieve the number of
	// devices present
	status = cl.CLGetDeviceIDs(platforms[0],
		cl.CL_DEVICE_TYPE_GPU,
		0,
		nil,
		&numDevices)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetDeviceIDs")

	// Allocate enough space for each device
	devices = make([]cl.CL_device_id, numDevices)

	// Fill in devices with clGetDeviceIDs()
	status = cl.CLGetDeviceIDs(platforms[0],
		cl.CL_DEVICE_TYPE_GPU,
		numDevices,
		devices,
		nil)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLGetDeviceIDs")

	//-----------------------------------------------------
	// STEP 3: Create a context
	//-----------------------------------------------------
	var context cl.CL_context

	// Create a context using clCreateContext() and
	// associate it with the devices
	context = cl.CLCreateContext(nil,
		numDevices,
		devices,
		nil,
		nil,
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateContext")
	defer cl.CLReleaseContext(context)

	//-----------------------------------------------------
	// STEP 4: Create a command queue
	//-----------------------------------------------------
	var commandQueue [MAX_COMMAND_QUEUE]cl.CL_command_queue

	// Create a command queue using clCreateCommandQueueWithProperties(),
	// and associate it with the device you want to execute
	for i := 0; i < MAX_COMMAND_QUEUE; i++ {
		commandQueue[i] = cl.CLCreateCommandQueueWithProperties(context,
			devices[0],
			nil,
			&status)
		utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateCommandQueueWithProperties")
		defer cl.CLReleaseCommandQueue(commandQueue[i])
	}

	//-----------------------------------------------------
	// STEP 5: Create device buffers
	//-----------------------------------------------------
	producerGroupSize := cl.CL_size_t(PRODUCER_GROUP_SIZE)
	producerGlobalSize := cl.CL_size_t(PRODUCER_GLOBAL_SIZE)

	consumerGroupSize := cl.CL_size_t(CONSUMER_GROUP_SIZE)
	consumerGlobalSize := cl.CL_size_t(CONSUMER_GLOBAL_SIZE)

	var samplePipePkt [2]cl.CL_float
	szPipe := cl.CL_uint(PIPE_SIZE)
	szPipePkt := cl.CL_uint(unsafe.Sizeof(samplePipePkt))
	if szPipe%PRNG_CHANNELS != 0 {
		szPipe = (szPipe/PRNG_CHANNELS)*PRNG_CHANNELS + PRNG_CHANNELS
	}
	consumerGlobalSize = cl.CL_size_t(szPipe)
	pipePktPerThread := cl.CL_int(szPipe) / PRNG_CHANNELS
	seed := cl.CL_int(SEED)
	rngType := cl.CL_int(RV_GAUSSIAN)
	var histMin cl.CL_float
	var histMax cl.CL_float
	if rngType == cl.CL_int(RV_UNIFORM) {
		histMin = 0.0
		histMax = 1.0
	} else {
		histMin = -10.0
		histMax = 10.0
	}

	localDevHist := make([]cl.CL_int, MAX_HIST_BINS)
	cpuHist := make([]cl.CL_int, MAX_HIST_BINS)

	//Create and initialize memory objects
	rngPipe := cl.CLCreatePipe(context,
		cl.CL_MEM_READ_WRITE,
		szPipePkt,
		szPipe,
		nil,
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clCreatePipe")

	devHist := cl.CLCreateBuffer(context,
		cl.CL_MEM_READ_WRITE|cl.CL_MEM_COPY_HOST_PTR,
		MAX_HIST_BINS*cl.CL_size_t(unsafe.Sizeof(localDevHist[0])),
		unsafe.Pointer(&localDevHist[0]),
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clCreateBuffer")

	//-----------------------------------------------------
	// STEP 6: Create and compile the program
	//-----------------------------------------------------
	programSource, programeSize := utils.Load_programsource("pipe.cl")

	// Create a program using clCreateProgramWithSource()
	program := cl.CLCreateProgramWithSource(context,
		1,
		programSource[:],
		programeSize[:],
		&status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateProgramWithSource")
	defer cl.CLReleaseProgram(program)

	// Build (compile) the program for the devices with
	// clBuildProgram()
	options := "-cl-std=CL2.0"
	status = cl.CLBuildProgram(program,
		numDevices,
		devices,
		[]byte(options),
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		var program_log interface{}
		var log_size cl.CL_size_t

		/* Find size of log and print to std output */
		cl.CLGetProgramBuildInfo(program, devices[0], cl.CL_PROGRAM_BUILD_LOG,
			0, nil, &log_size)
		cl.CLGetProgramBuildInfo(program, devices[0], cl.CL_PROGRAM_BUILD_LOG,
			log_size, &program_log, nil)
		fmt.Printf("%s\n", program_log)
		return
	}
	//utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLBuildProgram")

	//-----------------------------------------------------
	// STEP 7: Create the kernel
	//-----------------------------------------------------
	// Use clCreateKernel() to create a kernel
	produceKernel := cl.CLCreateKernel(program, []byte("pipe_producer"), &status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateKernel")
	defer cl.CLReleaseKernel(produceKernel)

	consumeKernel := cl.CLCreateKernel(program, []byte("pipe_consumer"), &status)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "CLCreateKernel")
	defer cl.CLReleaseKernel(consumeKernel)

	//-----------------------------------------------------
	// STEP 8: Set the kernel arguments
	//-----------------------------------------------------
	// Associate the input and output buffers with the
	// kernel
	// using clSetKernelArg()
	// Set appropriate arguments to the kernel
	status = cl.CLSetKernelArg(produceKernel,
		0,
		cl.CL_size_t(unsafe.Sizeof(rngPipe)),
		unsafe.Pointer(&rngPipe))

	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(rngPipe)")

	status = cl.CLSetKernelArg(produceKernel,
		1,
		cl.CL_size_t(unsafe.Sizeof(pipePktPerThread)),
		unsafe.Pointer(&pipePktPerThread))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(pipePktPerThread)")

	status = cl.CLSetKernelArg(produceKernel,
		2,
		cl.CL_size_t(unsafe.Sizeof(seed)),
		unsafe.Pointer(&seed))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(seed)")

	status = cl.CLSetKernelArg(produceKernel,
		3,
		cl.CL_size_t(unsafe.Sizeof(rngType)),
		unsafe.Pointer(&rngType))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(rngType)")

	//-----------------------------------------------------
	// STEP 9: Configure the work-item structure
	//-----------------------------------------------------
	// Define an index space (global work size) of work
	// items for
	// execution. A workgroup size (local work size) is not
	// required,
	// but can be used.
	// Enqueue both the kernels.
	var globalThreads = []cl.CL_size_t{producerGlobalSize}
	var localThreads = []cl.CL_size_t{producerGroupSize}

	//-----------------------------------------------------
	// STEP 10: Enqueue the kernel for execution
	//-----------------------------------------------------
	// Execute the kernel by using
	// clEnqueueNDRangeKernel().
	// 'globalWorkSize' is the 1D dimension of the
	// work-items
	var produceEvt [1]cl.CL_event
	status = cl.CLEnqueueNDRangeKernel(commandQueue[0],
		produceKernel,
		1,
		nil,
		globalThreads,
		localThreads,
		0,
		nil,
		&produceEvt[0])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clEnqueueNDRangeKernel")

	/*
	   launch consumer kernel only after producer has finished.
	   This is done to avoid concurrent kernels execution as the
	   memory consistency of pipe is guaranteed only across
	   synchronization points.
	*/
	status = cl.CLWaitForEvents(1, produceEvt[:])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clWaitForEvents(produceEvt)")

	//-----------------------------------------------------
	// STEP 8: Set the kernel arguments
	//-----------------------------------------------------
	// Associate the input and output buffers with the
	// kernel
	// using clSetKernelArg()
	// Set appropriate arguments to the kernel
	status = cl.CLSetKernelArg(consumeKernel,
		0,
		cl.CL_size_t(unsafe.Sizeof(rngPipe)),
		unsafe.Pointer(&rngPipe))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(rngPipe)")

	status = cl.CLSetKernelArg(consumeKernel,
		1,
		cl.CL_size_t(unsafe.Sizeof(devHist)),
		unsafe.Pointer(&devHist))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(devHist)")

	status = cl.CLSetKernelArg(consumeKernel,
		2,
		cl.CL_size_t(unsafe.Sizeof(histMin)),
		unsafe.Pointer(&histMin))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(histMin)")

	status = cl.CLSetKernelArg(consumeKernel,
		3,
		cl.CL_size_t(unsafe.Sizeof(histMax)),
		unsafe.Pointer(&histMax))
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clSetKernelArg(histMax)")

	//-----------------------------------------------------
	// STEP 9: Configure the work-item structure
	//-----------------------------------------------------
	// Define an index space (global work size) of work
	// items for
	// execution. A workgroup size (local work size) is not
	// required,
	// but can be used.
	globalThreads[0] = consumerGlobalSize
	localThreads[0] = consumerGroupSize

	//-----------------------------------------------------
	// STEP 10: Enqueue the kernel for execution
	//-----------------------------------------------------
	// Execute the kernel by using
	// clEnqueueNDRangeKernel().
	// 'globalWorkSize' is the 1D dimension of the
	// work-items
	var consumeEvt [1]cl.CL_event
	status = cl.CLEnqueueNDRangeKernel(
		commandQueue[1],
		consumeKernel,
		1,
		nil,
		globalThreads,
		localThreads,
		0,
		nil,
		&consumeEvt[0])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clEnqueueNDRangeKernel")

	status = cl.CLFlush(commandQueue[0])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clFlush(0)")

	status = cl.CLFlush(commandQueue[1])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clFlush(1)")

	//wait for kernels to finish
	status = cl.CLFinish(commandQueue[0])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clFinish(0)")

	status = cl.CLFinish(commandQueue[1])
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clFinish(1)")

	//-----------------------------------------------------
	// STEP 11: Read the output buffer back to the host
	//-----------------------------------------------------
	// Use clEnqueueReadBuffer() to read the OpenCL output
	// buffer (bufferC)
	// to the host output array (C)
	//copy the data back to host buffer
	var readEvt cl.CL_event
	status = cl.CLEnqueueReadBuffer(commandQueue[1],
		devHist,
		cl.CL_TRUE,
		0,
		(MAX_HIST_BINS)*cl.CL_size_t(unsafe.Sizeof(localDevHist[0])),
		unsafe.Pointer(&localDevHist[0]),
		0,
		nil,
		&readEvt)
	utils.CHECK_STATUS(status, cl.CL_SUCCESS, "clEnqueueReadBuffer")

	//-----------------------------------------------------
	// STEP 12: Verify the results
	//-----------------------------------------------------
	//Find the tolerance limit
	fTol := (float32)(CONSUMER_GLOBAL_SIZE) * (float32)(COMP_TOL) / (float32)(100.0)
	iTol := (int)(fTol)
	if iTol == 0 {
		iTol = 1
	}

	//CPU side histogram computation
	CPUReference(seed, pipePktPerThread, rngType, cpuHist, histMax, histMin)

	//Compare
	for bin := 0; bin < MAX_HIST_BINS; bin++ {
		diff := int(localDevHist[bin] - cpuHist[bin])

		if diff < 0 {
			diff = -diff
		}
		if diff > iTol {
			println("Failed!")
			return
		}
	}

	println("Passed!")
}
Example #4
0
func TestMatvec(t *testing.T) {
	/* Host/device data structures */
	var platform [1]cl.CL_platform_id
	var device [1]cl.CL_device_id
	var context cl.CL_context
	var queue cl.CL_command_queue
	var i, err cl.CL_int

	/* Program/kernel data structures */
	var program cl.CL_program
	var program_buffer [1][]byte
	var program_log interface{}
	var program_size [1]cl.CL_size_t
	var log_size cl.CL_size_t
	var kernel cl.CL_kernel

	/* Data and buffers */
	var mat [16]float32
	var vec, result [4]float32
	var correct = [4]float32{0.0, 0.0, 0.0, 0.0}
	var mat_buff, vec_buff, res_buff cl.CL_mem

	/* Initialize data to be processed by the kernel */
	for i = 0; i < 16; i++ {
		mat[i] = float32(i) * 2.0
	}

	for i = 0; i < 4; i++ {
		vec[i] = float32(i) * 3.0
		correct[0] += mat[i] * vec[i]
		correct[1] += mat[i+4] * vec[i]
		correct[2] += mat[i+8] * vec[i]
		correct[3] += mat[i+12] * vec[i]
	}

	/* Identify a platform */
	err = cl.CLGetPlatformIDs(1, platform[:], nil)
	if err < 0 {
		t.Errorf("Couldn't find any platforms")
	}

	/* Access a device */
	err = cl.CLGetDeviceIDs(platform[0], cl.CL_DEVICE_TYPE_GPU, 1, device[:], nil)
	if err < 0 {
		err = cl.CLGetDeviceIDs(platform[0], cl.CL_DEVICE_TYPE_CPU, 1, device[:], nil)
		if err < 0 {
			t.Errorf("Couldn't find any devices")
		}
	}

	/* Create the context */
	context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &err)
	if err < 0 {
		t.Errorf("Couldn't create a context")
	}

	/* Read program file and place content into buffer */
	program_handle, err1 := os.Open("matvec.cl")
	if err1 != nil {
		t.Errorf("Couldn't find the program file")
	}
	defer program_handle.Close()

	fi, err2 := program_handle.Stat()
	if err2 != nil {
		t.Errorf("Couldn't find the program stat")
	}
	program_size[0] = cl.CL_size_t(fi.Size())
	program_buffer[0] = make([]byte, program_size[0])
	read_size, err3 := program_handle.Read(program_buffer[0])
	if err3 != nil || cl.CL_size_t(read_size) != program_size[0] {
		t.Errorf("read file error or file size wrong")
	}

	/* Create a program containing all program content */
	program = cl.CLCreateProgramWithSource(context, 1,
		program_buffer[:], program_size[:], &err)
	if err < 0 {
		t.Errorf("Couldn't create the program")
	}

	/* Build program */
	err = cl.CLBuildProgram(program, 1, device[:], nil, nil, nil)
	if err < 0 {
		/* Find size of log and print to std output */
		cl.CLGetProgramBuildInfo(program, device[0], cl.CL_PROGRAM_BUILD_LOG,
			0, nil, &log_size)
		//program_log = (char*) malloc(log_size+1);
		//program_log[log_size] = '\0';
		cl.CLGetProgramBuildInfo(program, device[0], cl.CL_PROGRAM_BUILD_LOG,
			log_size, &program_log, nil)
		t.Errorf("%s\n", program_log)
		//free(program_log);
	}

	/* Create kernel for the mat_vec_mult function */
	kernel = cl.CLCreateKernel(program, []byte("matvec_mult"), &err)
	if err < 0 {
		t.Errorf("Couldn't create the kernel")
		return
	}

	/* Create CL buffers to hold input and output data */
	mat_buff = cl.CLCreateBuffer(context, cl.CL_MEM_READ_ONLY|
		cl.CL_MEM_COPY_HOST_PTR, cl.CL_size_t(unsafe.Sizeof(mat)), unsafe.Pointer(&mat[0]), &err)
	if err < 0 {
		t.Errorf("Couldn't create a buffer object")
		return
	}
	vec_buff = cl.CLCreateBuffer(context, cl.CL_MEM_READ_ONLY|
		cl.CL_MEM_COPY_HOST_PTR, cl.CL_size_t(unsafe.Sizeof(vec)), unsafe.Pointer(&vec[0]), nil)
	res_buff = cl.CLCreateBuffer(context, cl.CL_MEM_WRITE_ONLY,
		cl.CL_size_t(unsafe.Sizeof(result)), nil, nil)

	/* Create kernel arguments from the CL buffers */
	err = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(mat_buff)), unsafe.Pointer(&mat_buff))
	if err < 0 {
		t.Errorf("Couldn't set the kernel argument")
		return
	}
	cl.CLSetKernelArg(kernel, 1, cl.CL_size_t(unsafe.Sizeof(vec_buff)), unsafe.Pointer(&vec_buff))
	cl.CLSetKernelArg(kernel, 2, cl.CL_size_t(unsafe.Sizeof(res_buff)), unsafe.Pointer(&res_buff))

	/* Create a CL command queue for the device*/
	queue = cl.CLCreateCommandQueue(context, device[0], 0, &err)
	if err < 0 {
		t.Errorf("Couldn't create the command queue, errcode=%d\n", err)
		return
	}

	/* Enqueue the command queue to the device */
	var work_units_per_kernel = [1]cl.CL_size_t{4} /* 4 work-units per kernel */
	err = cl.CLEnqueueNDRangeKernel(queue, kernel, 1, nil, work_units_per_kernel[:],
		nil, 0, nil, nil)
	if err < 0 {
		t.Errorf("Couldn't enqueue the kernel execution command, errcode=%d\n", err)
		return
	}

	/* Read the result */
	err = cl.CLEnqueueReadBuffer(queue, res_buff, cl.CL_TRUE, 0, cl.CL_size_t(unsafe.Sizeof(result)),
		unsafe.Pointer(&result[0]), 0, nil, nil)
	if err < 0 {
		t.Errorf("Couldn't enqueue the read buffer command")
		return
	}

	/* Test the result */
	if (result[0] == correct[0]) && (result[1] == correct[1]) &&
		(result[2] == correct[2]) && (result[3] == correct[3]) {
		t.Logf("Matrix-vector multiplication successful.")
	} else {
		t.Errorf("Matrix-vector multiplication unsuccessful.")
	}

	/* Deallocate resources */
	cl.CLReleaseMemObject(mat_buff)
	cl.CLReleaseMemObject(vec_buff)
	cl.CLReleaseMemObject(res_buff)
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseCommandQueue(queue)
	cl.CLReleaseProgram(program)
	cl.CLReleaseContext(context)
}
Example #5
0
File: svmfg.go Project: xfong/gocl
func svmbasic(size cl.CL_size_t,
	context cl.CL_context,
	queue cl.CL_command_queue,
	kernel cl.CL_kernel) {
	// Prepare input data as follows.
	// Build two arrays:
	//     - an array that consists of the Element structures
	//       (refer to svmbasic.h for the structure definition)
	//     - an array that consists of the float values
	//
	// Each structure of the first array has the following pointers:
	//     - 'internal', which points to a 'value' field of another entry
	//       of the same array.
	//     - 'external', which points to a float value from the the
	//       second array.
	//
	// Pointers are set randomly. The structures do not reflect any real usage
	// scenario, but are illustrative for a simple device-side traversal.
	//
	//        Array of Element                        Array of floats
	//           structures
	//
	//    ||====================||
	//    ||    .............   ||                   ||============||
	//    ||    .............   ||<-----+            || .......... ||
	//    ||====================||      |            ||    float   ||
	//    ||   float* internal--||------+            ||    float   ||
	//    ||   float* external--||------------------>||    float   ||
	//    ||   float value <----||------+            || .......... ||
	//    ||====================||      |            || .......... ||
	//    ||    .............   ||      |            ||    float   ||
	//    ||    .............   ||      |            ||    float   ||
	//    ||====================||      |            ||    float   ||
	//    ||====================||      |            ||    float   ||
	//    ||   float* internal--||------+            ||    float   ||
	//    ||   float* external--||------------------>||    float   ||
	//    ||   float value      ||                   ||    float   ||
	//    ||====================||                   ||    float   ||
	//    ||    .............   ||                   || .......... ||
	//    ||    .............   ||                   ||============||
	//    ||====================||
	//
	// The two arrays are created independently and are used to illustrate
	// two new OpenCL 2.0 API functions:
	//    - the array of Element structures is passed to the kernel as a
	//      kernel argument with the clSetKernelArgSVMPointer function
	//    - the array of floats is used by the kernel indirectly, and this
	//      dependency should be also specified with the clSetKernelExecInfo
	//      function prior to the kernel execution

	var err cl.CL_int

	// To enable host & device code to share pointer to the same address space
	// the arrays should be allocated as SVM memory. Use the clSVMAlloc function
	// to allocate SVM memory.
	//
	// Optionally, this function allows specifying alignment in bytes as its
	// last argument. As this basic example doesn't require any _special_ alignment,
	// the following code illustrates requesting default alignment via passing
	// zero value.

	inputElements := cl.CLSVMAlloc(context, // the context where this memory is supposed to be used
		cl.CL_MEM_READ_ONLY|cl.CL_MEM_SVM_FINE_GRAIN_BUFFER,
		size*cl.CL_size_t(unsafe.Sizeof(sampleElement)), // amount of memory to allocate (in bytes)
		0) // alignment in bytes (0 means default)
	if nil == inputElements {
		println("Cannot allocate SVM memory with clSVMAlloc: it returns null pointer. You might be out of memory.")
		return
	}
	defer cl.CLSVMFree(context, inputElements)

	inputFloats := cl.CLSVMAlloc(context, // the context where this memory is supposed to be used
		cl.CL_MEM_READ_ONLY|cl.CL_MEM_SVM_FINE_GRAIN_BUFFER,
		size*cl.CL_size_t(unsafe.Sizeof(sampleFloat)), // amount of memory to allocate (in bytes)
		0) // alignment in bytes (0 means default)
	if nil == inputFloats {
		println("Cannot allocate SVM memory with clSVMAlloc: it returns null pointer. You might be out of memory.")
		return
	}
	defer cl.CLSVMFree(context, inputFloats)

	// The OpenCL kernel uses the aforementioned input arrays to compute
	// values for the output array.

	output := cl.CLSVMAlloc(context, // the context where this memory is supposed to be used
		cl.CL_MEM_WRITE_ONLY|cl.CL_MEM_SVM_FINE_GRAIN_BUFFER,
		size*cl.CL_size_t(unsafe.Sizeof(sampleFloat)), // amount of memory to allocate (in bytes)
		0) // alignment in bytes (0 means default)
	defer cl.CLSVMFree(context, output)

	if nil == output {
		println("Cannot allocate SVM memory with clSVMAlloc: it returns null pointer. You might be out of memory.")
		return
	}

	// Note: in the coarse-grained SVM, mapping of inputElement and inputFloats is
	// needed to do the following initialization. While here, in the fine-grained SVM,
	// it is not necessary.

	// Populate data-structures with initial data.
	r := rand.New(rand.NewSource(99))

	for i := cl.CL_size_t(0); i < size; i++ {
		inputElement := (*Element)(unsafe.Pointer(uintptr(inputElements) + uintptr(i)*unsafe.Sizeof(sampleElement)))
		inputFloat := (*cl.CL_float)(unsafe.Pointer(uintptr(inputFloats) + uintptr(i)*unsafe.Sizeof(sampleFloat)))
		randElement := (*Element)(unsafe.Pointer(uintptr(inputElements) + uintptr(r.Intn(int(size)))*unsafe.Sizeof(sampleElement)))
		randFloat := (*cl.CL_float)(unsafe.Pointer(uintptr(inputFloats) + uintptr(r.Intn(int(size)))*unsafe.Sizeof(sampleFloat)))

		inputElement.internal = &(randElement.value)
		inputElement.external = randFloat
		inputElement.value = cl.CL_float(i)
		*inputFloat = cl.CL_float(i + size)
	}

	// Note: in the coarse-grained SVM, unmapping of inputElement and inputFloats is
	// needed before scheduling the kernel for execution. While here, in the fine-grained SVM,
	// it is not necessary.

	// Pass arguments to the kernel.
	// According to the OpenCL 2.0 specification, you need to use a special
	// function to pass a pointer from SVM memory to kernel.

	err = cl.CLSetKernelArgSVMPointer(kernel, 0, inputElements)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLSetKernelArgSVMPointer")

	err = cl.CLSetKernelArgSVMPointer(kernel, 1, output)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLSetKernelArgSVMPointer")

	// For buffer based SVM (both coarse- and fine-grain) if one SVM buffer
	// points to memory allocated in another SVM buffer, such allocations
	// should be passed to the kernel via clSetKernelExecInfo.

	err = cl.CLSetKernelExecInfo(kernel,
		cl.CL_KERNEL_EXEC_INFO_SVM_PTRS,
		cl.CL_size_t(unsafe.Sizeof(inputFloats)),
		unsafe.Pointer(&inputFloats))
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLSetKernelExecInfo")

	// Run the kernel.
	println("Running kernel...")

	var globalWorkSize [1]cl.CL_size_t
	globalWorkSize[0] = size

	err = cl.CLEnqueueNDRangeKernel(queue,
		kernel,
		1,
		nil,
		globalWorkSize[:],
		nil,
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueNDRangeKernel")

	// Note: In the fine-grained SVM, after enqueuing the kernel above, the host application is
	// not blocked from accessing SVM allocations that were passed to the kernel. The host
	// can access the same regions of SVM memory as does the kernel if the kernel and the host
	// read/modify different bytes. If one side (host or device) needs to modify the same bytes
	// that are simultaniously read/modified by another side, atomics operations are usually
	// required to maintain sufficient memory consistency. This sample doesn't use this possibility
	// and the host just waits in clFinish below until the kernel is finished.
	err = cl.CLFinish(queue)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLFinish")

	println(" DONE.")

	// Validate output state for correctness.
	// Compare: in the coarse-grained SVM case you need to map the output.
	// Here it is not needed.

	println("Checking correctness of the output buffer...")
	for i := cl.CL_size_t(0); i < size; i++ {
		inputElement := (*Element)(unsafe.Pointer(uintptr(inputElements) + uintptr(i)*unsafe.Sizeof(sampleElement)))
		outputFloat := (*cl.CL_float)(unsafe.Pointer(uintptr(output) + uintptr(i)*unsafe.Sizeof(sampleFloat)))
		expectedValue := *(inputElement.internal) + *(inputElement.external)
		if *outputFloat != expectedValue {
			println(" FAILED.")
			fmt.Printf("Mismatch at position %d, read %f, expected %f\n", i, *outputFloat, expectedValue)
			return
		}
	}
	println(" PASSED.")
}
Example #6
0
func main() {
	// This code executes on the OpenCL host

	// Host data
	var size cl.CL_int
	var A []cl.CL_int //input array
	var B []cl.CL_int //input array
	var C []cl.CL_int //output array

	// Elements in each array
	const elements = cl.CL_size_t(2048)

	// Compute the size of the data
	datasize := cl.CL_size_t(unsafe.Sizeof(size)) * elements

	// Allocate space for input/output data
	A = make([]cl.CL_int, datasize)
	B = make([]cl.CL_int, datasize)
	C = make([]cl.CL_int, datasize)
	// Initialize the input data
	for i := cl.CL_int(0); i < cl.CL_int(elements); i++ {
		A[i] = i
		B[i] = i
	}

	// Use this to check the output of each API call
	var status cl.CL_int

	//-----------------------------------------------------
	// STEP 1: Discover and initialize the platforms
	//-----------------------------------------------------

	var numPlatforms cl.CL_uint
	var platforms []cl.CL_platform_id

	// Use clGetPlatformIDs() to retrieve the number of
	// platforms
	status = cl.CLGetPlatformIDs(0, nil, &numPlatforms)

	// Allocate enough space for each platform
	platforms = make([]cl.CL_platform_id, numPlatforms)

	// Fill in platforms with clGetPlatformIDs()
	status = cl.CLGetPlatformIDs(numPlatforms, platforms, nil)
	if status != cl.CL_SUCCESS {
		println("CLGetPlatformIDs status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 2: Discover and initialize the devices
	//-----------------------------------------------------

	var numDevices cl.CL_uint
	var devices []cl.CL_device_id

	// Use clGetDeviceIDs() to retrieve the number of
	// devices present
	status = cl.CLGetDeviceIDs(platforms[0],
		cl.CL_DEVICE_TYPE_ALL,
		0,
		nil,
		&numDevices)
	if status != cl.CL_SUCCESS {
		println("CLGetDeviceIDs status!=cl.CL_SUCCESS")
		return
	}

	// Allocate enough space for each device
	devices = make([]cl.CL_device_id, numDevices)

	// Fill in devices with clGetDeviceIDs()
	status = cl.CLGetDeviceIDs(platforms[0],
		cl.CL_DEVICE_TYPE_ALL,
		numDevices,
		devices,
		nil)
	if status != cl.CL_SUCCESS {
		println("CLGetDeviceIDs status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 3: Create a context
	//-----------------------------------------------------

	var context cl.CL_context

	// Create a context using clCreateContext() and
	// associate it with the devices
	context = cl.CLCreateContext(nil,
		numDevices,
		devices,
		nil,
		nil,
		&status)
	if status != cl.CL_SUCCESS {
		println("CLCreateContext status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 4: Create a command queue
	//-----------------------------------------------------

	var cmdQueue cl.CL_command_queue

	// Create a command queue using clCreateCommandQueue(),
	// and associate it with the device you want to execute
	// on
	cmdQueue = cl.CLCreateCommandQueue(context,
		devices[0],
		0,
		&status)
	if status != cl.CL_SUCCESS {
		println("CLCreateCommandQueue status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 5: Create device buffers
	//-----------------------------------------------------

	var bufferA cl.CL_mem // Input array on the device
	var bufferB cl.CL_mem // Input array on the device
	var bufferC cl.CL_mem // Output array on the device

	// Use clCreateBuffer() to create a buffer object (d_A)
	// that will contain the data from the host array A
	bufferA = cl.CLCreateBuffer(context,
		cl.CL_MEM_READ_ONLY,
		datasize,
		nil,
		&status)
	if status != cl.CL_SUCCESS {
		println("CLCreateBuffer status!=cl.CL_SUCCESS")
		return
	}
	// Use clCreateBuffer() to create a buffer object (d_B)
	// that will contain the data from the host array B
	bufferB = cl.CLCreateBuffer(context,
		cl.CL_MEM_READ_ONLY,
		datasize,
		nil,
		&status)
	if status != cl.CL_SUCCESS {
		println("CLCreateBuffer status!=cl.CL_SUCCESS")
		return
	}
	// Use clCreateBuffer() to create a buffer object (d_C)
	// with enough space to hold the output data
	bufferC = cl.CLCreateBuffer(context,
		cl.CL_MEM_WRITE_ONLY,
		datasize,
		nil,
		&status)
	if status != cl.CL_SUCCESS {
		println("CLCreateBuffer status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 6: Write host data to device buffers
	//-----------------------------------------------------

	// Use clEnqueueWriteBuffer() to write input array A to
	// the device buffer bufferA
	status = cl.CLEnqueueWriteBuffer(cmdQueue,
		bufferA,
		cl.CL_FALSE,
		0,
		datasize,
		unsafe.Pointer(&A[0]),
		0,
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		println("CLEnqueueWriteBuffer status!=cl.CL_SUCCESS")
		return
	}
	// Use clEnqueueWriteBuffer() to write input array B to
	// the device buffer bufferB
	status = cl.CLEnqueueWriteBuffer(cmdQueue,
		bufferB,
		cl.CL_FALSE,
		0,
		datasize,
		unsafe.Pointer(&B[0]),
		0,
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		println("CLEnqueueWriteBuffer status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 7: Create and compile the program
	//-----------------------------------------------------
	programSource, programeSize := utils.Load_programsource("chapter2.cl")

	// Create a program using clCreateProgramWithSource()
	program := cl.CLCreateProgramWithSource(context,
		1,
		programSource[:],
		programeSize[:],
		&status)
	if status != cl.CL_SUCCESS {
		println("CLCreateProgramWithSource status!=cl.CL_SUCCESS")
		return
	}
	// Build (compile) the program for the devices with
	// clBuildProgram()
	status = cl.CLBuildProgram(program,
		numDevices,
		devices,
		nil,
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		println("CLBuildProgram status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 8: Create the kernel
	//-----------------------------------------------------

	var kernel cl.CL_kernel

	// Use clCreateKernel() to create a kernel from the
	// vector addition function (named "vecadd")
	kernel = cl.CLCreateKernel(program, []byte("vecadd"), &status)
	if status != cl.CL_SUCCESS {
		println("CLCreateKernel status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 9: Set the kernel arguments
	//-----------------------------------------------------

	// Associate the input and output buffers with the
	// kernel
	// using clSetKernelArg()
	status = cl.CLSetKernelArg(kernel,
		0,
		cl.CL_size_t(unsafe.Sizeof(bufferA)),
		unsafe.Pointer(&bufferA))
	status |= cl.CLSetKernelArg(kernel,
		1,
		cl.CL_size_t(unsafe.Sizeof(bufferB)),
		unsafe.Pointer(&bufferB))
	status |= cl.CLSetKernelArg(kernel,
		2,
		cl.CL_size_t(unsafe.Sizeof(bufferC)),
		unsafe.Pointer(&bufferC))
	if status != cl.CL_SUCCESS {
		println("CLSetKernelArg status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 10: Configure the work-item structure
	//-----------------------------------------------------

	// Define an index space (global work size) of work
	// items for
	// execution. A workgroup size (local work size) is not
	// required,
	// but can be used.
	var globalWorkSize [1]cl.CL_size_t
	// There are 'elements' work-items
	globalWorkSize[0] = elements

	//-----------------------------------------------------
	// STEP 11: Enqueue the kernel for execution
	//-----------------------------------------------------

	// Execute the kernel by using
	// clEnqueueNDRangeKernel().
	// 'globalWorkSize' is the 1D dimension of the
	// work-items
	status = cl.CLEnqueueNDRangeKernel(cmdQueue,
		kernel,
		1,
		nil,
		globalWorkSize[:],
		nil,
		0,
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		println("CLEnqueueNDRangeKernel status!=cl.CL_SUCCESS")
		return
	}
	//-----------------------------------------------------
	// STEP 12: Read the output buffer back to the host
	//-----------------------------------------------------

	// Use clEnqueueReadBuffer() to read the OpenCL output
	// buffer (bufferC)
	// to the host output array (C)
	cl.CLEnqueueReadBuffer(cmdQueue,
		bufferC,
		cl.CL_TRUE,
		0,
		datasize,
		unsafe.Pointer(&C[0]),
		0,
		nil,
		nil)
	if status != cl.CL_SUCCESS {
		println("CLEnqueueReadBuffer status!=cl.CL_SUCCESS")
		return
	}
	// Verify the output
	result := true
	for i := cl.CL_int(0); i < cl.CL_int(elements); i++ {
		if C[i] != i+i {
			result = false
			break
		}
	}
	if result {
		println("Output is correct\n")
	} else {
		println("Output is incorrect\n")
	}

	//-----------------------------------------------------
	// STEP 13: Release OpenCL resources
	//-----------------------------------------------------

	// Free OpenCL resources
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseProgram(program)
	cl.CLReleaseCommandQueue(cmdQueue)
	cl.CLReleaseMemObject(bufferA)
	cl.CLReleaseMemObject(bufferB)
	cl.CLReleaseMemObject(bufferC)
	cl.CLReleaseContext(context)
}
Example #7
0
func main() {
	var i, j cl.CL_size_t
	// Rows and columns in the input image
	inputFile := "test.png"
	outputFile := "output.png"
	refFile := "ref.png"

	// Homegrown function to read a BMP from file
	inputpixels, imageWidth, imageHeight, err1 := utils.Read_image_data(inputFile)
	if err1 != nil {
		log.Fatal(err1)
		return
	} else {
		fmt.Printf("width=%d, height=%d (%d)\n", imageWidth, imageHeight, inputpixels[0])
	}

	// Output image on the host
	outputpixels := make([]uint16, imageHeight*imageWidth)
	inputImage := make([]float32, imageHeight*imageWidth)
	outputImage := make([]float32, imageHeight*imageWidth)
	refImage := make([]float32, imageHeight*imageWidth)

	for i = 0; i < imageHeight*imageWidth; i++ {
		inputImage[i] = float32(inputpixels[i])
	}

	// 45 degree motion blur
	var filter = [49]float32{0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0,
		0, 0, -1, 0, 1, 0, 0,
		0, 0, -2, 0, 2, 0, 0,
		0, 0, -1, 0, 1, 0, 0,
		0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0}

	// The convolution filter is 7x7
	filterWidth := cl.CL_size_t(7)
	filterSize := cl.CL_size_t(filterWidth * filterWidth) // Assume a square kernel

	// Set up the OpenCL environment
	var status cl.CL_int

	// Discovery platform
	var platform [1]cl.CL_platform_id
	status = cl.CLGetPlatformIDs(1, platform[:], nil)
	chk(status, "clGetPlatformIDs")

	// Discover device
	var device [1]cl.CL_device_id
	cl.CLGetDeviceIDs(platform[0], cl.CL_DEVICE_TYPE_ALL, 1, device[:], nil)
	chk(status, "clGetDeviceIDs")

	// Create context
	//var props =[3]cl.CL_context_properties{cl.CL_CONTEXT_PLATFORM,
	//    (cl.CL_context_properties)(unsafe.Pointer(&platform[0])), 0};

	var context cl.CL_context
	context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &status)
	chk(status, "clCreateContext")

	// Create command queue
	var queue cl.CL_command_queue
	queue = cl.CLCreateCommandQueue(context, device[0], 0, &status)
	chk(status, "clCreateCommandQueue")

	// The image format describes how the data will be stored in memory
	var format cl.CL_image_format
	format.Image_channel_order = cl.CL_R         // single channel
	format.Image_channel_data_type = cl.CL_FLOAT // float data type

	var desc cl.CL_image_desc
	desc.Image_type = cl.CL_MEM_OBJECT_IMAGE2D
	desc.Image_width = imageWidth
	desc.Image_height = imageHeight
	desc.Image_depth = 0
	desc.Image_array_size = 0
	desc.Image_row_pitch = 0
	desc.Image_slice_pitch = 0
	desc.Num_mip_levels = 0
	desc.Num_samples = 0
	desc.Buffer = cl.CL_mem{}

	// Create space for the source image on the device
	d_inputImage := cl.CLCreateImage(context, cl.CL_MEM_READ_ONLY, &format, &desc,
		nil, &status)
	chk(status, "clCreateImage")

	// Create space for the output image on the device
	d_outputImage := cl.CLCreateImage(context, cl.CL_MEM_WRITE_ONLY, &format, &desc,
		nil, &status)
	chk(status, "clCreateImage")

	// Create space for the 7x7 filter on the device
	d_filter := cl.CLCreateBuffer(context, 0, filterSize*cl.CL_size_t(unsafe.Sizeof(filter[0])),
		nil, &status)
	chk(status, "clCreateBuffer")

	// Copy the source image to the device
	var origin = [3]cl.CL_size_t{0, 0, 0}                                                // Offset within the image to copy from
	var region = [3]cl.CL_size_t{cl.CL_size_t(imageWidth), cl.CL_size_t(imageHeight), 1} // Elements to per dimension
	status = cl.CLEnqueueWriteImage(queue, d_inputImage, cl.CL_FALSE, origin, region,
		0, 0, unsafe.Pointer(&inputImage[0]), 0, nil, nil)
	chk(status, "clEnqueueWriteImage")

	// Copy the 7x7 filter to the device
	status = cl.CLEnqueueWriteBuffer(queue, d_filter, cl.CL_FALSE, 0,
		filterSize*cl.CL_size_t(unsafe.Sizeof(filter[0])), unsafe.Pointer(&filter[0]), 0, nil, nil)
	chk(status, "clEnqueueWriteBuffer")

	// Create the image sampler
	sampler := cl.CLCreateSampler(context, cl.CL_FALSE,
		cl.CL_ADDRESS_CLAMP_TO_EDGE, cl.CL_FILTER_NEAREST, &status)
	chk(status, "clCreateSampler")

	// Create a program object with source and build it
	program := utils.Build_program(context, device[:], "convolution.cl", nil)
	kernel := cl.CLCreateKernel(*program, []byte("convolution"), &status)
	chk(status, "clCreateKernel")

	// Set the kernel arguments
	var w, h, f cl.CL_int
	w = cl.CL_int(imageWidth)
	h = cl.CL_int(imageHeight)
	f = cl.CL_int(filterWidth)
	status = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(d_inputImage)), unsafe.Pointer(&d_inputImage))
	status |= cl.CLSetKernelArg(kernel, 1, cl.CL_size_t(unsafe.Sizeof(d_outputImage)), unsafe.Pointer(&d_outputImage))
	status |= cl.CLSetKernelArg(kernel, 2, cl.CL_size_t(unsafe.Sizeof(h)), unsafe.Pointer(&h))
	status |= cl.CLSetKernelArg(kernel, 3, cl.CL_size_t(unsafe.Sizeof(w)), unsafe.Pointer(&w))
	status |= cl.CLSetKernelArg(kernel, 4, cl.CL_size_t(unsafe.Sizeof(d_filter)), unsafe.Pointer(&d_filter))
	status |= cl.CLSetKernelArg(kernel, 5, cl.CL_size_t(unsafe.Sizeof(f)), unsafe.Pointer(&f))
	status |= cl.CLSetKernelArg(kernel, 6, cl.CL_size_t(unsafe.Sizeof(sampler)), unsafe.Pointer(&sampler))
	chk(status, "clSetKernelArg")

	// Set the work item dimensions
	var globalSize = [2]cl.CL_size_t{imageWidth, imageHeight}
	status = cl.CLEnqueueNDRangeKernel(queue, kernel, 2, nil, globalSize[:], nil, 0,
		nil, nil)
	chk(status, "clEnqueueNDRange")

	// Read the image back to the host
	status = cl.CLEnqueueReadImage(queue, d_outputImage, cl.CL_TRUE, origin,
		region, 0, 0, unsafe.Pointer(&outputImage[0]), 0, nil, nil)
	chk(status, "clEnqueueReadImage")

	// Write the output image to file
	for i = 0; i < imageHeight*imageWidth; i++ {
		outputpixels[i] = uint16(outputImage[i])
	}
	utils.Write_image_data(outputFile, outputpixels, imageWidth, imageHeight)

	// Compute the reference image
	for i = 0; i < imageHeight; i++ {
		for j = 0; j < imageWidth; j++ {
			refImage[i*imageWidth+j] = 0
		}
	}

	// Iterate over the rows of the source image
	halfFilterWidth := filterWidth / 2
	var sum float32
	for i = 0; i < imageHeight; i++ {
		// Iterate over the columns of the source image
		for j = 0; j < imageWidth; j++ {
			sum = 0 // Reset sum for new source pixel
			// Apply the filter to the neighborhood
			for k := -halfFilterWidth; k <= halfFilterWidth; k++ {
				for l := -halfFilterWidth; l <= halfFilterWidth; l++ {
					if i+k >= 0 && i+k < imageHeight &&
						j+l >= 0 && j+l < imageWidth {
						sum += inputImage[(i+k)*imageWidth+j+l] *
							filter[(k+halfFilterWidth)*filterWidth+
								l+halfFilterWidth]
					} else {
						i_k := i + k
						j_l := j + l
						if i+k < 0 {
							i_k = 0
						} else if i+k >= imageHeight {
							i_k = imageHeight - 1
						}
						if j+l < 0 {
							j_l = 0
						} else if j+l >= imageWidth {
							j_l = imageWidth - 1
						}
						sum += inputImage[(i_k)*imageWidth+j_l] *
							filter[(k+halfFilterWidth)*filterWidth+
								l+halfFilterWidth]
					}
				}
			}
			refImage[i*imageWidth+j] = sum
		}
	}
	// Write the ref image to file
	for i = 0; i < imageHeight*imageWidth; i++ {
		outputpixels[i] = uint16(refImage[i])
	}
	utils.Write_image_data(refFile, outputpixels, imageWidth, imageHeight)

	failed := 0
	for i = 0; i < imageHeight; i++ {
		for j = 0; j < imageWidth; j++ {
			if math.Abs(float64(outputImage[i*imageWidth+j]-refImage[i*imageWidth+j])) > 0.01 {
				//fmt.Printf("Results are INCORRECT\n");
				//fmt.Printf("Pixel mismatch at <%d,%d> (%f vs. %f) %f\n", i, j,
				//   outputImage[i*imageWidth+j], refImage[i*imageWidth+j], inputImage[i*imageWidth+j]);
				failed++
			}
		}
	}
	fmt.Printf("Mismatch Pixel number/Total pixel number = %d/%d\n", failed, imageWidth*imageHeight)

	// Free OpenCL resources
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseProgram(*program)
	cl.CLReleaseCommandQueue(queue)
	cl.CLReleaseMemObject(d_inputImage)
	cl.CLReleaseMemObject(d_outputImage)
	cl.CLReleaseMemObject(d_filter)
	cl.CLReleaseSampler(sampler)
	cl.CLReleaseContext(context)
}
Example #8
0
func main() {

	/* OpenCL data structures */
	var device []cl.CL_device_id
	var context cl.CL_context
	var queue cl.CL_command_queue
	var program *cl.CL_program
	var kernel cl.CL_kernel
	var err cl.CL_int

	var err1 error
	var global_size [2]cl.CL_size_t

	/* Image data */
	var pixels []uint16
	var png_format cl.CL_image_format
	var input_image, output_image cl.CL_mem
	var origin, region [3]cl.CL_size_t
	var width, height cl.CL_size_t

	/* Open input file and read image data */
	pixels, width, height, err1 = utils.Read_image_data(INPUT_FILE)
	if err1 != nil {
		return
	} else {
		fmt.Printf("width=%d, height=%d", width, height)
	}

	/* Create a device and context */
	device = utils.Create_device()
	context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &err)
	if err < 0 {
		println("Couldn't create a context")
		return
	}

	/* Build the program and create a kernel */
	program = utils.Build_program(context, device[:], PROGRAM_FILE, nil)
	kernel = cl.CLCreateKernel(*program, KERNEL_FUNC, &err)
	if err < 0 {
		fmt.Printf("Couldn't create a kernel: %d", err)
		return
	}

	/* Create image object */
	png_format.Image_channel_order = cl.CL_LUMINANCE
	png_format.Image_channel_data_type = cl.CL_UNORM_INT16
	input_image = cl.CLCreateImage2D(context,
		cl.CL_MEM_READ_ONLY|cl.CL_MEM_COPY_HOST_PTR,
		&png_format, width, height, 0, unsafe.Pointer(&pixels[0]), &err)
	output_image = cl.CLCreateImage2D(context,
		cl.CL_MEM_WRITE_ONLY, &png_format, width, height, 0, nil, &err)
	if err < 0 {
		println("Couldn't create the image object")
		return
	}

	/* Create kernel arguments */
	err = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(input_image)), unsafe.Pointer(&input_image))
	err |= cl.CLSetKernelArg(kernel, 1, cl.CL_size_t(unsafe.Sizeof(output_image)), unsafe.Pointer(&output_image))
	if err < 0 {
		println("Couldn't set a kernel argument")
		return
	}

	/* Create a command queue */
	queue = cl.CLCreateCommandQueue(context, device[0], 0, &err)
	if err < 0 {
		println("Couldn't create a command queue")
		return
	}

	/* Enqueue kernel */
	global_size[0] = width
	global_size[1] = height
	err = cl.CLEnqueueNDRangeKernel(queue, kernel, 2, nil, global_size[:],
		nil, 0, nil, nil)
	if err < 0 {
		println("Couldn't enqueue the kernel")
		return
	}

	/* Read the image object */
	origin[0] = 0
	origin[1] = 0
	origin[2] = 0
	region[0] = width
	region[1] = height
	region[2] = 1
	err = cl.CLEnqueueReadImage(queue, output_image, cl.CL_TRUE, origin,
		region, 0, 0, unsafe.Pointer(&pixels[0]), 0, nil, nil)
	if err < 0 {
		println("Couldn't read from the image object")
		return
	}

	/* Create output PNG file and write data */
	utils.Write_image_data(OUTPUT_FILE, pixels, width, height)

	/* Deallocate resources */
	cl.CLReleaseMemObject(input_image)
	cl.CLReleaseMemObject(output_image)
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseCommandQueue(queue)
	cl.CLReleaseProgram(*program)
	cl.CLReleaseContext(context)

}
Example #9
0
func main() {

	/* OpenCL data structures */
	var device []cl.CL_device_id
	var context cl.CL_context
	var queue cl.CL_command_queue
	var program *cl.CL_program
	var kernel cl.CL_kernel
	var err cl.CL_int

	/* Data and buffers */
	dim := cl.CL_uint(2)
	var global_offset = [2]cl.CL_size_t{3, 5}
	var global_size = [2]cl.CL_size_t{6, 4}
	var local_size = [2]cl.CL_size_t{3, 2}
	var test [24]float32
	var test_buffer cl.CL_mem

	/* Create a device and context */
	device = utils.Create_device()
	context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &err)
	if err < 0 {
		println("Couldn't create a context")
		return
	}

	/* Build the program and create a kernel */
	program = utils.Build_program(context, device[:], PROGRAM_FILE, nil)
	kernel = cl.CLCreateKernel(*program, KERNEL_FUNC, &err)
	if err < 0 {
		println("Couldn't create a kernel")
		return
	}

	/* Create a write-only buffer to hold the output data */
	test_buffer = cl.CLCreateBuffer(context, cl.CL_MEM_WRITE_ONLY,
		cl.CL_size_t(unsafe.Sizeof(test)), nil, &err)
	if err < 0 {
		println("Couldn't create a buffer")
		return
	}

	/* Create kernel argument */
	err = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(test_buffer)), unsafe.Pointer(&test_buffer))
	if err < 0 {
		println("Couldn't set a kernel argument")
		return
	}

	/* Create a command queue */
	queue = cl.CLCreateCommandQueue(context, device[0], 0, &err)
	if err < 0 {
		println("Couldn't create a command queue")
		return
	}

	/* Enqueue kernel */
	err = cl.CLEnqueueNDRangeKernel(queue, kernel, dim, global_offset[:],
		global_size[:], local_size[:], 0, nil, nil)
	if err < 0 {
		println("Couldn't enqueue the kernel")
		return
	}

	/* Read and print the result */
	err = cl.CLEnqueueReadBuffer(queue, test_buffer, cl.CL_TRUE, 0,
		cl.CL_size_t(unsafe.Sizeof(test)), unsafe.Pointer(&test), 0, nil, nil)
	if err < 0 {
		println("Couldn't read the buffer")
		return
	}

	for i := 0; i < 24; i += 6 {
		fmt.Printf("%.2f     %.2f     %.2f     %.2f     %.2f     %.2f\n",
			test[i], test[i+1], test[i+2], test[i+3], test[i+4], test[i+5])
	}

	/* Deallocate resources */
	cl.CLReleaseMemObject(test_buffer)
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseCommandQueue(queue)
	cl.CLReleaseProgram(*program)
	cl.CLReleaseContext(context)
}
Example #10
0
File: atomic.go Project: xfong/gocl
func main() {

	/* OpenCL data structures */
	var device []cl.CL_device_id
	var context cl.CL_context
	var queue cl.CL_command_queue
	var program *cl.CL_program
	var kernel cl.CL_kernel
	var err cl.CL_int

	var offset, global_size, local_size [1]cl.CL_size_t

	/* Data and events */
	var data [2]cl.CL_int
	var data_buffer cl.CL_mem

	/* Create a device and context */
	device = utils.Create_device()
	context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &err)
	if err < 0 {
		println("Couldn't create a context")
		return
	}

	/* Build the program and create a kernel */
	program = utils.Build_program(context, device[:], PROGRAM_FILE, nil)
	kernel = cl.CLCreateKernel(*program, KERNEL_FUNC, &err)
	if err < 0 {
		println("Couldn't create a kernel")
		return
	}

	/* Create a buffer to hold data */
	data_buffer = cl.CLCreateBuffer(context, cl.CL_MEM_WRITE_ONLY,
		cl.CL_size_t(unsafe.Sizeof(data[0]))*2, nil, &err)
	if err < 0 {
		println("Couldn't create a buffer")
		return
	}

	/* Create kernel argument */
	err = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(data_buffer)), unsafe.Pointer(&data_buffer))
	if err < 0 {
		println("Couldn't set a kernel argument")
		return
	}

	/* Create a command queue */
	queue = cl.CLCreateCommandQueue(context, device[0], 0, &err)
	if err < 0 {
		println("Couldn't create a command queue")
		return
	}

	/* Enqueue kernel */
	offset[0] = 0
	global_size[0] = 8
	local_size[0] = 4
	err = cl.CLEnqueueNDRangeKernel(queue, kernel, 1, offset[:], global_size[:], local_size[:], 0, nil, nil)
	if err < 0 {
		println("Couldn't enqueue the kernel")
		return
	}

	/* Read the buffer */
	err = cl.CLEnqueueReadBuffer(queue, data_buffer, cl.CL_TRUE, 0,
		cl.CL_size_t(unsafe.Sizeof(data[0]))*2, unsafe.Pointer(&data[0]), 0, nil, nil)
	if err < 0 {
		println("Couldn't read the buffer")
		return
	}

	fmt.Printf("Increment: %d\n", data[0])
	fmt.Printf("Atomic increment: %d\n", data[1])

	/* Deallocate resources */
	cl.CLReleaseMemObject(data_buffer)
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseCommandQueue(queue)
	cl.CLReleaseProgram(*program)
	cl.CLReleaseContext(context)
}
Example #11
0
func main() {

	/* OpenCL data structures */
	var device []cl.CL_device_id
	var context cl.CL_context
	var queue cl.CL_command_queue
	var program *cl.CL_program
	var kernel cl.CL_kernel
	var err cl.CL_int

	/* Data and events */
	var num_ints cl.CL_int
	var num_items [1]cl.CL_size_t
	var data [NUM_INTS]cl.CL_int
	var data_buffer cl.CL_mem
	var prof_event cl.CL_event
	var total_time cl.CL_ulong
	var time_start, time_end interface{}

	/* Initialize data */
	for i := 0; i < NUM_INTS; i++ {
		data[i] = cl.CL_int(i)
	}

	/* Set number of data points and work-items */
	num_ints = NUM_INTS
	num_items[0] = NUM_ITEMS

	/* Create a device and context */
	device = utils.Create_device()
	context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &err)
	if err < 0 {
		println("Couldn't create a context")
		return
	}

	/* Build the program and create a kernel */
	program = utils.Build_program(context, device[:], PROGRAM_FILE, nil)
	kernel = cl.CLCreateKernel(*program, KERNEL_FUNC, &err)
	if err < 0 {
		println("Couldn't create a kernel")
		return
	}

	/* Create a buffer to hold data */
	data_buffer = cl.CLCreateBuffer(context,
		cl.CL_MEM_READ_WRITE|cl.CL_MEM_COPY_HOST_PTR,
		cl.CL_size_t(unsafe.Sizeof(data[0]))*NUM_INTS, unsafe.Pointer(&data[0]), &err)
	if err < 0 {
		println("Couldn't create a buffer")
		return
	}

	/* Create kernel argument */
	err = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(data_buffer)), unsafe.Pointer(&data_buffer))
	if err < 0 {
		println("Couldn't set a kernel argument")
		return
	}
	cl.CLSetKernelArg(kernel, 1, cl.CL_size_t(unsafe.Sizeof(num_ints)), unsafe.Pointer(&num_ints))

	/* Create a command queue */
	queue = cl.CLCreateCommandQueue(context, device[0],
		cl.CL_QUEUE_PROFILING_ENABLE, &err)
	if err < 0 {
		println("Couldn't create a command queue")
		return
	}

	total_time = 0.0
	for i := 0; i < NUM_ITERATIONS; i++ {

		/* Enqueue kernel */
		cl.CLEnqueueNDRangeKernel(queue, kernel, 1, nil, num_items[:],
			nil, 0, nil, &prof_event)
		if err < 0 {
			println("Couldn't enqueue the kernel")
			return
		}

		/* Finish processing the queue and get profiling information */
		cl.CLFinish(queue)
		cl.CLGetEventProfilingInfo(prof_event, cl.CL_PROFILING_COMMAND_START,
			cl.CL_size_t(unsafe.Sizeof(total_time)), &time_start, nil)
		cl.CLGetEventProfilingInfo(prof_event, cl.CL_PROFILING_COMMAND_END,
			cl.CL_size_t(unsafe.Sizeof(total_time)), &time_end, nil)
		total_time += time_end.(cl.CL_ulong) - time_start.(cl.CL_ulong)
	}
	fmt.Printf("Average time = %v\n", total_time/NUM_ITERATIONS)

	/* Deallocate resources */
	cl.CLReleaseEvent(prof_event)
	cl.CLReleaseKernel(kernel)
	cl.CLReleaseMemObject(data_buffer)
	cl.CLReleaseCommandQueue(queue)
	cl.CLReleaseProgram(*program)
	cl.CLReleaseContext(context)
}
Example #12
0
File: svmcg.go Project: xfong/gocl
func svmbasic(size cl.CL_size_t,
	context cl.CL_context,
	queue cl.CL_command_queue,
	kernel cl.CL_kernel) {
	// Prepare input data as follows.
	// Build two arrays:
	//     - an array that consists of the Element structures
	//       (refer to svmbasic.h for the structure definition)
	//     - an array that consists of the float values
	//
	// Each structure of the first array has the following pointers:
	//     - 'internal', which points to a 'value' field of another entry
	//       of the same array.
	//     - 'external', which points to a float value from the the
	//       second array.
	//
	// Pointers are set randomly. The structures do not reflect any real usage
	// scenario, but are illustrative for a simple device-side traversal.
	//
	//        Array of Element                        Array of floats
	//           structures
	//
	//    ||====================||
	//    ||    .............   ||                   ||============||
	//    ||    .............   ||<-----+            || .......... ||
	//    ||====================||      |            ||    float   ||
	//    ||   float* internal--||------+            ||    float   ||
	//    ||   float* external--||------------------>||    float   ||
	//    ||   float value <----||------+            || .......... ||
	//    ||====================||      |            || .......... ||
	//    ||    .............   ||      |            ||    float   ||
	//    ||    .............   ||      |            ||    float   ||
	//    ||====================||      |            ||    float   ||
	//    ||====================||      |            ||    float   ||
	//    ||   float* internal--||------+            ||    float   ||
	//    ||   float* external--||------------------>||    float   ||
	//    ||   float value      ||                   ||    float   ||
	//    ||====================||                   ||    float   ||
	//    ||    .............   ||                   || .......... ||
	//    ||    .............   ||                   ||============||
	//    ||====================||
	//
	// The two arrays are created independently and are used to illustrate
	// two new OpenCL 2.0 API functions:
	//    - the array of Element structures is passed to the kernel as a
	//      kernel argument with the clSetKernelArgSVMPointer function
	//    - the array of floats is used by the kernel indirectly, and this
	//      dependency should be also specified with the clSetKernelExecInfo
	//      function prior to the kernel execution

	var err cl.CL_int

	// To enable host & device code to share pointer to the same address space
	// the arrays should be allocated as SVM memory. Use the clSVMAlloc function
	// to allocate SVM memory.
	//
	// Optionally, this function allows specifying alignment in bytes as its
	// last argument. As this basic example doesn't require any _special_ alignment,
	// the following code illustrates requesting default alignment via passing
	// zero value.

	inputElements := cl.CLSVMAlloc(context, // the context where this memory is supposed to be used
		cl.CL_MEM_READ_ONLY,
		size*cl.CL_size_t(unsafe.Sizeof(sampleElement)), // amount of memory to allocate (in bytes)
		0) // alignment in bytes (0 means default)
	if nil == inputElements {
		println("Cannot allocate SVM memory with clSVMAlloc: it returns null pointer. You might be out of memory.")
		return
	}
	defer cl.CLSVMFree(context, inputElements)

	inputFloats := cl.CLSVMAlloc(context, // the context where this memory is supposed to be used
		cl.CL_MEM_READ_ONLY,
		size*cl.CL_size_t(unsafe.Sizeof(sampleFloat)), // amount of memory to allocate (in bytes)
		0) // alignment in bytes (0 means default)
	if nil == inputFloats {
		println("Cannot allocate SVM memory with clSVMAlloc: it returns null pointer. You might be out of memory.")
		return
	}
	defer cl.CLSVMFree(context, inputFloats)

	// The OpenCL kernel uses the aforementioned input arrays to compute
	// values for the output array.

	output := cl.CLSVMAlloc(context, // the context where this memory is supposed to be used
		cl.CL_MEM_WRITE_ONLY,
		size*cl.CL_size_t(unsafe.Sizeof(sampleFloat)), // amount of memory to allocate (in bytes)
		0) // alignment in bytes (0 means default)
	defer cl.CLSVMFree(context, output)

	if nil == output {
		println("Cannot allocate SVM memory with clSVMAlloc: it returns null pointer. You might be out of memory.")
		return
	}

	// In the coarse-grained buffer SVM model, only one OpenCL device (or
	// host) can have ownership for writing to the buffer. Specifically, host
	// explicitly requests the ownership by mapping/unmapping the SVM buffer.
	//
	// So to fill the input SVM buffers on the host, you need to map them to have
	// access from the host program.
	//
	// The following two map calls are required in case of coarse-grained SVM only.

	err = cl.CLEnqueueSVMMap(queue,
		cl.CL_TRUE, // blocking map
		cl.CL_MAP_WRITE,
		inputElements,
		size*cl.CL_size_t(unsafe.Sizeof(sampleElement)),
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueSVMMap")

	err = cl.CLEnqueueSVMMap(queue,
		cl.CL_TRUE, // blocking map
		cl.CL_MAP_WRITE,
		inputFloats,
		size*cl.CL_size_t(unsafe.Sizeof(sampleFloat)),
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueSVMMap")

	// Populate data-structures with initial data.
	r := rand.New(rand.NewSource(99))

	for i := cl.CL_size_t(0); i < size; i++ {
		inputElement := (*Element)(unsafe.Pointer(uintptr(inputElements) + uintptr(i)*unsafe.Sizeof(sampleElement)))
		inputFloat := (*cl.CL_float)(unsafe.Pointer(uintptr(inputFloats) + uintptr(i)*unsafe.Sizeof(sampleFloat)))
		randElement := (*Element)(unsafe.Pointer(uintptr(inputElements) + uintptr(r.Intn(int(size)))*unsafe.Sizeof(sampleElement)))
		randFloat := (*cl.CL_float)(unsafe.Pointer(uintptr(inputFloats) + uintptr(r.Intn(int(size)))*unsafe.Sizeof(sampleFloat)))

		inputElement.internal = &(randElement.value)
		inputElement.external = randFloat
		inputElement.value = cl.CL_float(i)
		*inputFloat = cl.CL_float(i + size)
	}

	// The following two unmap calls are required in case of coarse-grained SVM only

	err = cl.CLEnqueueSVMUnmap(queue,
		inputElements,
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueSVMUnmap")

	err = cl.CLEnqueueSVMUnmap(queue,
		inputFloats,
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueSVMUnmap")

	// Pass arguments to the kernel.
	// According to the OpenCL 2.0 specification, you need to use a special
	// function to pass a pointer from SVM memory to kernel.

	err = cl.CLSetKernelArgSVMPointer(kernel, 0, inputElements)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLSetKernelArgSVMPointer")

	err = cl.CLSetKernelArgSVMPointer(kernel, 1, output)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLSetKernelArgSVMPointer")

	// For buffer based SVM (both coarse- and fine-grain) if one SVM buffer
	// points to memory allocated in another SVM buffer, such allocations
	// should be passed to the kernel via clSetKernelExecInfo.

	err = cl.CLSetKernelExecInfo(kernel,
		cl.CL_KERNEL_EXEC_INFO_SVM_PTRS,
		cl.CL_size_t(unsafe.Sizeof(inputFloats)),
		unsafe.Pointer(&inputFloats))
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLSetKernelExecInfo")

	// Run the kernel.
	println("Running kernel...")

	var globalWorkSize [1]cl.CL_size_t
	globalWorkSize[0] = size

	err = cl.CLEnqueueNDRangeKernel(queue,
		kernel,
		1,
		nil,
		globalWorkSize[:],
		nil,
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueNDRangeKernel")

	// Map the output SVM buffer to read the results.
	// Mapping is required for coarse-grained SVM only.

	err = cl.CLEnqueueSVMMap(queue,
		cl.CL_TRUE, // blocking map
		cl.CL_MAP_READ,
		output,
		size*cl.CL_size_t(unsafe.Sizeof(sampleFloat)),
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueSVMMap")

	println(" DONE.")

	// Validate output state for correctness.

	println("Checking correctness of the output buffer...")
	for i := cl.CL_size_t(0); i < size; i++ {
		inputElement := (*Element)(unsafe.Pointer(uintptr(inputElements) + uintptr(i)*unsafe.Sizeof(sampleElement)))
		outputFloat := (*cl.CL_float)(unsafe.Pointer(uintptr(output) + uintptr(i)*unsafe.Sizeof(sampleFloat)))
		expectedValue := *(inputElement.internal) + *(inputElement.external)
		if *outputFloat != expectedValue {
			println(" FAILED.")
			fmt.Printf("Mismatch at position %d, read %f, expected %f\n", i, *outputFloat, expectedValue)
			return
		}
	}
	println(" PASSED.")

	err = cl.CLEnqueueSVMUnmap(queue,
		output,
		0,
		nil,
		nil)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLEnqueueSVMUnmap")

	err = cl.CLFinish(queue)
	utils.CHECK_STATUS(err, cl.CL_SUCCESS, "CLFinish")
}