Test

main.cpp

#include <iostream>                                                                                                                                                    
#include <chrono>

void __attribute__ ((noinline)) init(int *arr, size_t length) {
  for (auto i = 0; i < length; ++i) {
    arr[i] = 1;
  }
}


void __attribute__ ((noinline)) compute(int *vec1, int *vec2, int *vec3, size_t length) {
  for (auto i = 0; i < length; ++i) {
    vec3[i] += vec1[i] * vec2[i];
  }
}


int main() {
  size_t length = 1000000;
  size_t times = 100;
  int *vec1 = new int[length];
  int *vec2 = new int[length];
  int *vec3 = new int[length];

  init(vec1, length);
  init(vec2, length);
  init(vec3, length);

  auto start = std::chrono::system_clock::now();

  for (size_t i = 0; i < times; ++i) {
    compute(vec1, vec2, vec3, length);
  }

  auto end = std::chrono::system_clock::now();
  std::chrono::duration<double> diff = end - start;
  std::cout << "Time: " << diff.count() << std::endl;
  
  delete [] vec1;
  delete [] vec2;
  delete [] vec3;

  return 0;
}