win32- 函数运行速度测试

LARGE_INTEGER nFreq, t1, t2;
int loop_count = 0;
double dt;
double time_sum = 0;

QueryPerformanceFrequency(&nFreq);
QueryPerformanceCounter(&t1);
/* 要测试的函数 */
void TestFunction();
QueryPerformanceCounter(&t2);
dt = (t2.QuadPart - t1.QuadPart) / (double)nFreq.QuadPart;
time_sum += dt * 1000;
loop_count++;
// 函数跑一千次的总时间
if (loop_count == 1000) {
  char out8[128] = {0};
  sprintf(out8, "%lf", time_sum);
  OutputDebugStringA(out8);
  loop_count = 0;
  time_sum = 0;
}

最终以 ms 为单位，在输出窗口打印，也可以使用 std::cout 打印结果