return new PhysicalRegisterEnumeration(FIRST_DOUBLE+FIRST_SCRATCH_FPR,
return new PhysicalRegisterEnumeration(FIRST_DOUBLE+FIRST_VOLATILE_FPR,
  Enumeration enumerateVolatileFPRs() {    return new PhysicalRegisterEnumeration(FIRST_DOUBLE+FIRST_SCRATCH_FPR,                                           FIRST_DOUBLE+LAST_VOLATILE_FPR);  }