// counters
counter(8192, CounterType.packets) c;

action count(bit<32> index) {
    //increment counter at index
    c.count(index);
}

// registers
register<bit<48>>(16384) r;

action ipg(out bit<48> ival, bit<32> x) {
  bit<48> last;
  bit<48> now;
  r.read(last, x);
  now = std_meta.ingress_global_timestamp;
  ival = now - last;
  r.write(x, now);
}