SonarCloud instance reports a problem here:
"Identical sub-expressions on both sides of operator "&&"."

  bool swapped = false;

  if (in_bb(gin1) && in_bb(gin2) && in_bb(fin1) && in_bb(fin1)) { // <----
    if (same_origin_idx(gin1, fin1) &&
        same_origin_idx(gin2, fin2)) {
      return true; // nothing to fix
    }

I believe it should have been "in_bb(fin1) && in_bb(fin2)".

Seems to be that way since JDK-8076284.