#include <iostream>
#include <chrono>
#include <cmath>
int main()
{
	auto begin = std::chrono::high_resolution_clock::now();
	
	double i, sum, fib, run;
	for (run = 0; run < 5e6; run++)
	{
		for (i = sum = fib = 0; fib < 13e8; sum += ((int)fib & 1) ? fib : 0, (fib = floor(pow((1 + sqrt(5)) / 2, i++) / sqrt(5) + 0.5)));
	}

	auto end = std::chrono::high_resolution_clock::now();
	auto duration = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin).count();
	std::cout << "+ " << sum << std::endl;
	std::cout << (i*run) << " iterations run in " << (double)duration << "ns total, average : " << duration / (i*run) << "ns." << std::endl;

	return 0;
}

+ 1.48561e+09
2.35e+08 iterations run in 8.17514e+09ns total, average : 34.7878ns.