Loop unrolling

for.cpp

#include <iostream>

void for1(int x)
{
    int* arr = new int[x];

    for (int i = 0; i < x; i++)
    {
        arr[i] = i;
    }

    delete[] arr;
}
void for2(int x)
{
    int* arr = new int[x];
    int end = x / 4;
    for (int i = 0; i < end; i++)
    {
        arr[i] = i;
        arr[i + 1] = i + 1;
        arr[i + 2] = i + 2;
        arr[i + 3] = i + 3;
    }

    delete[] arr;
}

int main()
{
    const int count = 4 * 1000 * 1000 * 100;

    clock_t s = clock();
    for1(count);
    //for2(count);
    clock_t end = clock() - s;
    std::cout << (end / 1000) << std::endl;

	return 0;
}