public static synchronized Offset findOrCreateDoubleLiteral(long literal) {
public static synchronized int findOrCreateDoubleLiteral(long literal) {
  public static synchronized Offset findOrCreateDoubleLiteral(long literal) {    Integer off = (Integer)doubleLiterals.get(new Long(literal)); // NOTE: keep mapping in terms of long bits    if (off != null) return Offset.fromIntSignExtend(off.intValue());    int newOff = allocateSlot(DOUBLE_LITERAL);    doubleLiterals.put(new Long(literal), new Integer(newOff));    Offset offset = Offset.fromIntSignExtend(newOff);    setSlotContents(offset, literal);    return offset;  }