struct Options {
  // kDefaultMicros specifies the default time to run the benchmark, and is used
  // if neither max_iters nor max_micros is set.
  static constexpr int64_t kDefaultMicros = 3000000;

  int64_t max_iters = 0;   // Maximum iterations to run, ignored if <= 0.
  int64_t max_micros = 0;  // Maximum microseconds to run, ignored if <= 0.
};

// Stats holds statistics collected during benchmarking.
struct Stats {

  // If neither max_seconds or max_iters is set, stop at kDefaultMicros.
  const int64_t max_us = (options.max_micros <= 0 && options.max_iters <= 0)
                             ? Options::kDefaultMicros
                             : options.max_micros;
  // NOLINTNEXTLINE
  printf("Running benchmark for %lld us\n", static_cast<long long>(max_us));
  const int64_t start_us = NowMicros();