text: //------------------------------------------------------------------------------------------------------------------------------
  // Samuel Williams
  // SWWilliams@lbl.gov
  // Lawrence Berkeley National Lab
  //------------------------------------------------------------------------------------------------------------------------------
  #include <stdint.h>
  uint64_t CycleTime(){
    uint64_t lo, hi;
    __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
    return( (((uint64_t)hi) << 32) | ((uint64_t)lo) );
  }
  