add.cpp

#include <iostream>
#include <math.h>

// CUDA programming example
//   https://developer.nvidia.com/blog/even-easier-introduction-cuda/

// Non CUDA Kernal function to add elements of two arrays
void add(int n, float *x, float*y)
{
    for (int i = 0; i < n; i++)
        y[i] = x[i] + y[i];
}

int main(void)
{
    int N = 1<<20; // 1M elements

    float *x = new float[N];
    float *y = new float[N];

    // initialize x and y arrays on the host
    for (int i = 0; i < N; i++) {
        x[i] = 1.0f;
        y[i] = 2.0f;
    }

    // Run function on 1M elements on the CPU
    add(N, x, y);

    // Check for errors (all values should be 3.0f)
    float maxError = 0.0f;
    for (int i = 0; i < N; i++)
        maxError = fmax(maxError, fabs(y[i]-3.0f));
    std::cout << "Max error: " << maxError << std::endl;

    // Free memory
    delete [] x;
    delete [] y;

    return 0;
}