比较精确的获取的时间消耗

#ifndef TIMER_HPP_

#define TIMER_HPP_

class Timer

{

typedef unsigned __int64 Time;

static const Time FREQ = 2200000000;//CPU 频率  相当于2.2GHZ

Time time_;

static Time rdtsc()

{

__asm rdtsc

}

public:

Timer() : time_( rdtsc() )

{}

void restart()

{

time_ = rdtsc();

}

double diff() const

{

return (double)( rdtsc() - time_ ) / FREQ;

}

};

#endif//TIMER_HPP_