none/tests/ppc32/bug139050-ppc32.c

   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  }