Recursive Graphs - Recursive Graphs - 2026.1 English - UG1079

template<int Level>
class RecursiveGraph: public adf::graph {
private:
  adf::kernel k;
  RecursiveGraph<Level-1> RG;

public:
  adf::port<input> din;
  adf::port<output> dout;

  RecursiveGraph() {
    k = adf::kernel::create(passthrough);
    adf::source(k) = "kernels.cpp";
    adf::runtime<ratio>(k) = 0.9;

    adf::connect(din, k.in[0]);
    adf::connect(k.out[0], RG.din);
    adf::connect(RG.dout, dout);
  };
};


template<>
class RecursiveGraph<1>: public adf::graph {
private:
  adf::kernel k;

public:
  adf::port<input> din;
  adf::port<output> dout;

  RecursiveGraph() {
    k = adf::kernel::create(passthrough);
    adf::source(k) = "kernels.cpp";
    adf::runtime<ratio>(k) = 0.9;

    adf::connect(din, k.in[0]);
    adf::connect(k.out[0], dout);
  };
};

The class RecursiveGraph is parametrized with the template parameter Level which represents the depth of the recursive function. Within the RecursiveGraph class, an instantiati on of the same class is performed as RecursiveGraph<Level-1> RG;with the template parameter Level-1. This recursively instantiates RecursiveGraph Level-1 times. The RecursiveGraph<1> class specialization behaves as the stop condition of the recursion.

class TestRecursiveGraph: public adf::graph {
public:
  adf::input_plio plin;
  adf::output_plio plout;

  RecursiveGraph<5> Recursive;

  TestRecursiveGraph()
  {
    plin = adf::input_plio::create("input",adf::plio_64_bits,"data/Input_64.txt",500);
    adf::connect(plin.out[0],Recursive.din);

    plout = adf::output_plio::create("output",adf::plio_64_bits,"data/Output.txt",500);
    adf::connect(Recursive.dout,plout.in[0]);
  };
};

In the following example, five instances of RecursiveGraph are instantiated in the TestRecursiveGraph graph.

TestRecursiveGraph RecursiveUnitTest;

int main(int argc, char ** argv) {

  RecursiveUnitTest.init();
  RecursiveUnitTest.run(NFRAMES*NITERATIONS);
  RecursiveUnitTest.end();
  return 0;
}

The following figure shows the recursive graph as opposed to a sequential graph view obtained in the Vitis IDE.

Figure 1. Recursive Graph and Sequential Multi-kernel Graph View

The hierarchy obtained using recursivity is clearly visible in the graph view.