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  1. #1
    Join Date
    Oct 2016

    addition program in jcuda

    I am novice to JCUDA. I am trying to compile a vector addition program from NVIDIA samples using eclipse on windows.( for that I installed cuda 6.5 toolkit also

    Here is my program:

    import static jcuda.driver.JCudaDriver.*;
                import jcuda.*;
                import jcuda.driver.*;
                * This is a sample class demonstrating how to use the JCuda driver
                * bindings to load and execute a CUDA vector addition kernel.
                * The sample reads a CUDA file, compiles it to a PTX file
                * using NVCC, loads the PTX file as a module and executes
                * the kernel function. <br />
                public class TestSampleCuda
                     * Entry point of this sample
                     * @param args Not used
                     * @throws IOException If an IO error occurs
                    public static void main(String args[]) throws IOException
                        // Enable exceptions and omit all subsequent error checks
                        // Create the PTX file by calling the NVCC
                       String ptxFileName = preparePtxFile("C:\\Users\\590943\\workspace\\Assignments\\");
                //        String ptxFileName = "C:\\Users\\590943\\workspace\\Assignments\\JCudaVectorAddKernel.ptx";
                        // Initialize the driver and create a context for the first device.
                        CUdevice device = new CUdevice();
                        cuDeviceGet(device, 0);
                        CUcontext context = new CUcontext();
                        cuCtxCreate(context, 0, device);
                        // Load the ptx file.
                        CUmodule module = new CUmodule();
                        cuModuleLoad(module, ptxFileName);
                        // Obtain a function pointer to the "add" function.
                        CUfunction function = new CUfunction();
                        cuModuleGetFunction(function, module, "add");
                        int numElements = 1000000;
                        // Allocate and fill the host input data
                        float hostInputA[] = new float[numElements];
                        float hostInputB[] = new float[numElements];
                        for(int i = 0; i < numElements; i++)
                            hostInputA[i] = (float)i;
                            hostInputB[i] = (float)i;
                        // Allocate the device input data, and copy the
                        // host input data to the device
                        CUdeviceptr deviceInputA = new CUdeviceptr();
                        cuMemAlloc(deviceInputA, numElements * Sizeof.FLOAT);
                            numElements * Sizeof.FLOAT);
                        CUdeviceptr deviceInputB = new CUdeviceptr();
                        cuMemAlloc(deviceInputB, numElements * Sizeof.FLOAT);
                            numElements * Sizeof.FLOAT);
                        // Allocate device output memory
                        CUdeviceptr deviceOutput = new CUdeviceptr();
                        cuMemAlloc(deviceOutput, numElements * Sizeof.FLOAT);
                        // Set up the kernel parameters: A pointer to an array
                        // of pointers which point to the actual values.
                        Pointer kernelParameters =
                        // Call the kernel function.
                        int blockSizeX = 256;
                        int gridSizeX = (int)Math.ceil((double)numElements / blockSizeX);
                            gridSizeX,  1, 1,      // Grid dimension
                            blockSizeX, 1, 1,      // Block dimension
                            0, null,               // Shared memory size and stream
                            kernelParameters, null // Kernel- and extra parameters
                        // Allocate host output memory and copy the device output
                        // to the host.
                        float hostOutput[] = new float[numElements];
                        cuMemcpyDtoH(, deviceOutput,
                            numElements * Sizeof.FLOAT);
                        // Verify the result
                        boolean passed = true;
                        for(int i = 0; i < numElements; i++)
                            float expected = i+i;
                            if (Math.abs(hostOutput[i] - expected) > 1e-5)
                                    "At index "+i+ " found "+hostOutput[i]+
                                    " but expected "+expected);
                                passed = false;
                        System.out.println("Test "+(passed?"PASSED":"FAILED"));
                        // Clean up.
                     * The extension of the given file name is replaced with "ptx".
                     * If the file with the resulting name does not exist, it is
                     * compiled from the given file using NVCC. The name of the
                     * PTX file is returned.
                     * @param cuFileName The name of the .CU file
                     * @return The name of the PTX file
                     * @throws IOException If an I/O error occurs
                    private static String preparePtxFile(String cuFileName) throws IOException
                        int endIndex = cuFileName.lastIndexOf('.');
                        if (endIndex == -1)
                            endIndex = cuFileName.length()-1;
                        String ptxFileName = cuFileName.substring(0, endIndex+1)+"ptx";
                        //File ptxFile = new File(ptxFileName);
                        File ptxFile = new File(ptxFileName);
                        if (ptxFile.exists())
                            return ptxFileName;
                        File cuFile = new File(cuFileName);
                        if (!cuFile.exists())
                            throw new IOException("Input file not found: "+cuFileName);
                        String modelString = "-m"+System.getProperty("");
                        String command =
                            "nvcc " + modelString + " -ptx "+
                            cuFile.getPath()+" -o "+ptxFileName;
                        Process process = Runtime.getRuntime().exec(command);
                        String errorMessage =
                            new String(toByteArray(process.getErrorStream()));
                        String outputMessage =
                            new String(toByteArray(process.getInputStream()));
                        int exitValue = 0;
                            exitValue = process.waitFor();
                        catch (InterruptedException e)
                            throw new IOException(
                                "Interrupted while waiting for nvcc output", e);
                        if (exitValue != 0)
                            System.out.println("nvcc process exitValue "+exitValue);
                            throw new IOException(
                                "Could not create .ptx file: "+errorMessage);
                        System.out.println("Finished creating PTX file");
                        return ptxFileName;
                     * Fully reads the given InputStream and returns it as a byte array
                     * @param inputStream The input stream to read
                     * @return The byte array containing the data from the input stream
                     * @throws IOException If an I/O error occurs
                    private static byte[] toByteArray(InputStream inputStream)
                        throws IOException
                        ByteArrayOutputStream baos = new ByteArrayOutputStream();
                        byte buffer[] = new byte[8192];
                        while (true)
                            int read =;
                            if (read == -1)
                            baos.write(buffer, 0, read);
                        return baos.toByteArray();

    Exception in thread "main"
    C:\Users\590943\workspace\Assignments\ Input file not found:
    at TestSampleCuda.preparePtxFile(
    at TestSampleCuda.main(

    Can you plz help me??
    Last edited by 2kaud; October 4th, 2016 at 05:43 AM. Reason: Added code tags

  2. #2
    2kaud's Avatar
    2kaud is offline Super Moderator Power Poster
    Join Date
    Dec 2012

    Re: addition program in jcuda

    When posting code, please use code tags. Go Advanced, select the formatted code and click '#'.

    Isn't this a duplicate of the post here ??
    All advice is offered in good faith only. All my code is tested (unless stated explicitly otherwise) with the latest version of Microsoft Visual Studio (using the supported features of the latest standard) and is offered as examples only - not as production quality. I cannot offer advice regarding any other c/c++ compiler/IDE or incompatibilities with VS. You are ultimately responsible for the effects of your programs and the integrity of the machines they run on. Anything I post, code snippets, advice, etc is licensed as Public Domain and can be used without reference or acknowledgement. Also note that I only provide advice and guidance via the forums - and not via private messages!

    C++20 Compiler: Microsoft VS2022 (17.0.2)

  3. #3
    Join Date
    Sep 2016

    Re: addition program in jcuda

    import java.util.Scanner;
    class AddNumbers
       public static void main(String args[])
          int x, y, z;
          System.out.println("Enter two integers to calculate their sum ");
          Scanner in = new Scanner(;
          x = in.nextInt();
          y = in.nextInt();
          z = x + y;
          System.out.println("Sum of entered integers = "+z);
    Last edited by 2kaud; October 4th, 2016 at 08:13 AM. Reason: Code tags added

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