reSIR(toplevelSIR, toplevel, new HashSet());
reSIR(toplevelSIR, toplevel, new HashSet<FlatNode>());
    public FlatGraphToSIR(FlatNode top)     {        toplevel = top;        id = 0;        toplevelSIR = new SIRPipeline("TopLevel" + globalID++);        reSIR(toplevelSIR, toplevel, new HashSet());    }