message: implement GetCurrentClockCycle() for s390x
diff: @@ -109,6 +109,12 @@ class CpuUtils {
  "\tbne 0b \n"
  : "=r"(upper), "=r"(lower), "=r"(tmp));
  return ((static_cast<uint64>(upper) << 32) | lower);
  +#elif defined(__s390x__)
  + // TOD Clock of s390x runs at a different frequency than the CPU's.
  + // The stepping is 244 picoseconds (~4Ghz).
  + uint64 t;
  + __asm__ __volatile__("stckf %0" : "=Q"(t));
  + return t;
  #else
  // TODO(satok): Support generic way to emulate clock count.
  // TODO(satok): Support other architectures if wanted.
  