Method GroupIds

source/diff/diff.cpp:944–963

// `uint32_t`.
template <typename T>
void Differ::GroupIds(const IdGroup& ids, bool is_src,
                      std::map<T, IdGroup>* groups,
                      T (Differ::*get_group)(const IdInstructions&, uint32_t)) {
  assert(groups->empty());

  const IdInstructions& id_to = is_src ? src_id_to_ : dst_id_to_;

  for (const uint32_t id : ids) {
    // Don't include ids that are already matched, for example through
    // OpEntryPoint.
    const bool is_matched =
        is_src ? id_map_.IsSrcMapped(id) : id_map_.IsDstMapped(id);
    if (is_matched) {
      continue;
    }

    T group = (this->*get_group)(id_to, id);
    (*groups)[group].push_back(id);
  }
}

// Group `src_ids` and `dst_ids` according to `get_group`, and then use
// `match_group` to pair up ids in corresponding groups.