private static void recordBottom (VM_Method m, VM_Field f) {
private static synchronized  void recordBottom (VM_Method m, VM_Field f) {
  private static void recordBottom (VM_Method m, VM_Field f) {    // for now, only track private fields    if (!f.isPrivate())      return;    if (isTrouble(f))      return;    OPT_FieldDatabase.FieldDatabaseEntry entry = db.findOrCreateEntry(f);    OPT_FieldDatabase.FieldWriterInfo info = entry.findMethodInfo(m);    if (VM.VerifyAssertions) {      if (info == null)        VM.sysWrite("ERROR recordBottom: method " + m + " field " + f);      VM._assert(info != null);    }    info.setBottom();    info.setAnalyzed();  }