}
    std::sort(pre_screen.begin(), pre_screen.end());

    for (; !pre_screen.empty(); pre_screen.pop_back()) {
      const auto& [max_savings, begin, end] = pre_screen.back();
      const auto insert_before = FindBestRematPoint(begin, end, peak.op_index);
      if (insert_before == operations_.size()) {
        continue;
      }
      const RematSpec this_remat = {begin, end, insert_before};

  // If I want to remat ops [begin, end) after the op at operation `peak_loc`,
  // find the latest point at which to reinsert them (the op before which to
  // insert.)
  int FindBestRematPoint(int begin, int end, int peak_loc) const;

  // The memory objects.
  struct Tensor {
    SizeT size;                   // The size of the object (in bytes.)