Q5(b).cc

#include <iostream> // for cin, cout
#include <time.h>   // for clock_gettime
#include <cstdlib>  // for rand, srand

using namespace std;

// Function to generate a number from [-bound, bound]
template <typename T>
T GenerateRandomNumber(double bound)
{
    return (rand() / (double)RAND_MAX) * 2 * bound - bound;
}

// Create a array of 'size' floats in the range [-bound, bound]
template <typename T>
T *GenerateRandomArray(int size, double bound)
{
    T *array = new T[size];
    for (int i = 0; i < size; i++)
    {
        array[i] = GenerateRandomNumber<T>(bound);
    }
    return array;
}

template <typename T>
void UpdateCoords(T *xs, T *ys, T *zs, T *vx, T *vy, T *vz, int size)
{
    for (int i = 0; i < size; i++)
    {
        xs[i] += vx[i];
        ys[i] += vy[i];
        zs[i] += vz[i];
    }
}

template <typename T>
void test(int size, int iters)
{
    cout << "Testing with size = " << size << " and iters = " << iters << endl;
    T *xs = GenerateRandomArray<T>(size, 1000);
    T *ys = GenerateRandomArray<T>(size, 1000);
    T *zs = GenerateRandomArray<T>(size, 1000);
    T *vx = GenerateRandomArray<T>(size, 1);
    T *vy = GenerateRandomArray<T>(size, 1);
    T *vz = GenerateRandomArray<T>(size, 1);
    timespec start, end;
    if (clock_gettime(CLOCK_MONOTONIC, &start) != 0)
    {
        cout << "Error getting start time" << endl;
    }
    for (int i = 0; i < iters; i++)
    {
        UpdateCoords<T>(xs, ys, zs, vx, vy, vz, size);
    }
    if (clock_gettime(CLOCK_MONOTONIC, &end) != 0)
    {
        cout << "Error getting end time" << endl;
    }
    double start_us = start.tv_sec * 1e6 + start.tv_nsec / 1e3;
    double end_us = end.tv_sec * 1e6 + end.tv_nsec / 1e3;
    double total_time_us = end_us - start_us;
    double chksum = 0;
    for (int i = 0; i < size; i++)
    {
        chksum += xs[i] + ys[i] + zs[i];
    }
    cout << "Mean time per coordinate: " << total_time_us / (size * iters) << " us" << endl;
    cout << "Checksum: " << chksum << endl;
}

int main()
{
    srand(20220921);
    // test with size = 28, iters = 100000
    test<float>(28, 100000);
    // test with size = 56, iters = 100000
    test<float>(56, 100000);
    // test with size = 112, iters = 100000
    test<float>(112, 100000);
    // test with size = 224, iters = 100000
    test<float>(224, 100000);
    return 0;
}