AddrStack.displacement += disp;
AddrStack.displacement = AddrStack.displacement.add(disp);
  protected final void augmentAddress(OPT_Operand op) {    if (VM.VerifyAssertions) VM._assert(AddrStack != null, "No address to augment");    if (op.isRegister()) {      OPT_RegisterOperand rop = op.asRegister();      if (AddrStack.base == null) {        AddrStack.base = rop;      } else if (AddrStack.index == null) {        if (VM.VerifyAssertions) VM._assert(AddrStack.scale == (byte)0);        AddrStack.index = rop;      } else {        throw new OPT_OptimizingCompilerException("three base registers in address");      }    } else {      int disp = ((OPT_IntConstantOperand)op).value;      AddrStack.displacement += disp;    }  }