rdtsc时间戳

【tsc】

time stamp counter

【性能】

大概只要chrono接口的1/6时延

【测试程序】

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

#include <x86intrin.h> #include <chrono> #include <cstdio>   using namespace std::chrono; int main(){     u_int64_t begin = duration_cast<nanoseconds>(steady_clock::now().time_since_epoch()).count();     for(int i=0;i<100000;i++){         u_int64_t a = __rdtsc(); //        u_int64_t a = duration_cast<nanoseconds>(steady_clock::now().time_since_epoch()).count();     }     u_int64_t end = duration_cast<nanoseconds>(steady_clock::now().time_since_epoch()).count();     printf("time_elapsed=%llu\n", end - begin);     return 0; }