Random vs Non-random, C++ (vc++)

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#include <iostream>
#include <iomanip>
#include <chrono>
#include <cstdint>
#include <vector>

#define N 100000
#define M 100000000

#define RANDOM 0

// Testing function 'F' with time duration variable 'D'
#define TEST(F, D)      \
  begin = get_now();    \
  a = 0;                \
  do {                  \
    s+=(u32)F;          \
  } while (++a != M);   \
  end = get_now();      \
  auto D = end - begin;

// Output working time of -0's and -1's functions
#define OUT(S, N) output_vs (S, N##0_time - empty, N##1_time - empty);

typedef int32_t  i32;
typedef uint32_t u32;
typedef int8_t   sign_t;

const u32 SHIFT = 31;

using namespace std;

// Some helpers

static chrono::high_resolution_clock::time_point get_now() {
	return chrono::high_resolution_clock::now();
}

static void output_vs(const char * str, const chrono::high_resolution_clock::duration &duration0, const chrono::high_resolution_clock::duration &duration1) {
	cout << str << ": " << fixed << setprecision(2) << chrono::duration_cast <chrono::duration<double>> (duration0).count() << " vs "
		<< fixed << setprecision(2) << chrono::duration_cast <chrono::duration<double>> (duration1).count() << endl;
}

// Sign functions

static sign_t sign0(i32 a) {
	if (a>0)  return +1;
	if (a<0)  return -1;
	return 0;
}

static sign_t sign1(i32 a) {
	return (a >> SHIFT) | ((u32)(-a) >> SHIFT);
}

int main() {

u32 a, s = 0;
	chrono::high_resolution_clock::time_point begin, end;
	
	std::vector<i32> v;
	for (size_t i = 0; i < N; i++) {
#if RANDOM
		v.push_back(rand() - RAND_MAX / 2);
#else
		v.push_back(i - N / 2);
#endif
	}

// Empty loop
	TEST(a, empty)

// Testing the functions
		TEST(sign0(i32(v[a % N])), sign0_time)
		TEST(sign1(i32(v[a % N])), sign1_time)

// Output the result
		OUT("sign", sign)

// Output 's' to avoid aggressive optimization (removing useless loops).
		// ('volatile' is not a good way to achieve the same effect).
		cerr << s << endl;

return 0;
}

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Compilation time: 1,97 sec, absolute running time: 1,2 sec, absolute service time: 3,19 sec