cmake/TestARMv7CycleCounters.cpp

   1 int main()
   2 {
   3 #if defined(__ARM_ARCH_7A__) && defined(__GNUC__)
   4     unsigned int cycles_lo, cycles_hi;
   5     asm volatile("mrrc p15, 1, %0, %1, c14" : "=r" (cycles_lo), "=r" (cycles_hi));
   6
   7     // Return 0 (success) if low or high 32 bits contained anything non-trivial
   8     return !(cycles_lo > 0 || cycles_hi > 0);
   9 #else
  10 #error This architecture/compiler does not support ARMv7 32-bit cycle counters
  11 #endif
  12 }