C语言计算代码执行所耗CPU时钟周期

#include "windows.h"

LARGE_INTEGER _start = { 0 }, _end = { 0 };
__asm{
  rdtsc
  mov dword ptr [_start.LowPart], eax
  mov dword ptr[_start.HighPart], edx
}

//your code here

__asm{
  rdtsc
  mov dword ptr [_end.LowPart], eax
  mov dword ptr[_end.HighPart], edx
}

long interval = static_cast<long>(_end.QuadPart - _start.QuadPart);