1 2 #include <stdio.h> 3 #include <assert.h> 4 5 typedef unsigned long long int ULong; 6 typedef unsigned int UInt; 7 8 static ULong GetCPU_ClockCyclesSinceStartup(void) 9 { 10 UInt uTimeBaseLow; 11 UInt uTimeBaseHigh; 12 UInt uCheck; 13 __asm__ __volatile__("1: mfspr %0,269\n\t" 14 " mfspr %1,268\n\t" 15 " mfspr %2,269\n\t" 16 " cmpw %2, %0\n\t" 17 " bne 1b" 18 : "=r" (uTimeBaseHigh), 19 "=r" (uTimeBaseLow), 20 "=r" (uCheck) 21 : /*in*/ 22 : /*trash*/ "cr0","cr7" ); 23 24 return (((ULong)(uTimeBaseHigh) << 32) | uTimeBaseLow); 25 } 26 27 int main(int argc, char** argv) 28 { 29 ULong cys = GetCPU_ClockCyclesSinceStartup(); 30 /* implausible that machine has been up less than 4G cycles */ 31 assert(cys > (1ULL << 32)); 32 printf("success\n"); 33 return 0; 34 } 35
