if (newNumber < phys.getSize()) {
if (newNumber < OPT_PhysicalRegisterSet.getSize()) {
  void cloneTo(OPT_Register reg, OPT_IR ir) {    int newNumber = reg.number;    OPT_PhysicalRegisterSet phys = ir.regpool.getPhysicalRegisterSet();    if (newNumber < phys.getSize()) {       number = newNumber;      flags  = phys.get(number).flags;    }  }