os.writeMOV(INTSIZE, T0, SP, 0); helper.writePUSH(T0);
    public final void visit_dup() {        //TODO: port to orp-style        os.log("dup");        vstack.push(eContext);        Item v1 = vstack.popItem();        vstack.pushItem(v1);        vstack.pushItem(v1);        os.writeMOV(INTSIZE, T0, SP, 0); // Value1, leave on stack        helper.writePUSH(T0);    }