#include <stdio.h> #define MAX_LEN 1000000 static inline void prefetchnta(void *addr) //预取部分 {     __asm__("movl %0, %%eax"::"a"(addr));     __asm__(".byte 0x0f, 0x18, 0x00"); } inline unsigned long long GetCPUTickCount() {     unsigned long high32 = 0;     unsigned long low32 = 0;     __asm__("RDTSC" : "=a"(low32), "=d"(high32));     unsigned long long counter = high32;     counter = (counter<<32) + low32;     return counter; } int main(int argc, char* argv[]) {     long long start, end;     long long array[MAX_LEN];     int i;     for(i = 0; i < MAX_LEN； i++) //让cache失效         array[i]++;     start = GetCPUTickCount();     array[0]++;     end = GetCPUTickCount();     printf("don't use prefetch time:%ld\n", end - start);     for(i = 0; i < MAX_LEN； i++)         array[i]++;     prefetchnta(array);     start = GetCPUTickCount();     array[0]++;     end = GetCPUTickCount();     printf("use prefetch time:%ld\n", end - start);     return 0; }