Commit df4a8ca3 authored by Dmitry I. Lyakh's avatar Dmitry I. Lyakh
Browse files

Fixed an issue in ExaTN-gen related to the unnecessary output tensor creation. 



Signed-off-by: default avatarDmitry I. Lyakh <quant4me@gmail.com>
parent 4199b178

examples/exatn_gen/exatn_reconstruct_visitor.cpp

+8 −7
Original line number Diff line number Diff line
@@ -87,23 +87,24 @@ int benchmarkExaTnGen2() 


int benchmarkExaTnGen3()

{

 constexpr int NB_QUBITS = 16;

 constexpr int NB_QUBITS = 8;

 auto xasmCompiler = xacc::getCompiler("xasm");

 auto ir = xasmCompiler->compile(R"(__qpu__ void bell(qbit q) {

            H(q[0]);

            for (int i = 0; i < 15; i++) {

            for (int i = 0; i < 7; i++) {

             CNOT(q[i], q[i + 1]);

            }

           })");

 std::vector<int> bitstring(NB_QUBITS, 0);

 std::vector<int> bitstring(NB_QUBITS, 0); // -1: Open qubits

 auto program = ir->getComposite("bell");

 auto accelerator =

      xacc::getAccelerator("tnqvm", {{"tnqvm-visitor", "exatn-gen"},

      xacc::getAccelerator("tnqvm", {{"tnqvm-visitor", "exatn-gen:float"},

                                     {"exatn-buffer-size-gb", 2},

                                     {"reconstruct-layers", 4},

                                     {"reconstruct-layers", 2},

                                     {"reconstruct-tolerance", 1e-4},

                                     {"max-bond-dim", 1},

                                     {"bitstring", bitstring}});

                                     {"max-bond-dim", 4},

                                     {"bitstring", bitstring},

                                     {"exatn-contract-seq-optimizer", "metis"}});

 auto qreg = xacc::qalloc(NB_QUBITS);

 accelerator->execute(qreg, program);

 qreg->print();

tnqvm/visitors/exatn-gen/ExatnGenVisitor.cpp

+1 −2
Original line number Diff line number Diff line
@@ -729,8 +729,7 @@ void ExatnGenVisitor<TNQVM_COMPLEX_TYPE>::reconstructCircuitTensor(bool forced) 
            exatn::makeSharedTensorNetwork("Approx", rootTensor, *builder);

        for (auto iter = approximantTensorNetwork->cbegin();

             iter != approximantTensorNetwork->cend(); ++iter) {

          const auto &tensorName = iter->second.getTensor()->getName();

          if (tensorName != "ROOT") {

          if (iter->first != 0) { //ignore output tensor

            auto tensor = iter->second.getTensor();

            const bool created =

                exatn::createTensorSync(tensor, getExatnElementType());

tnqvm/visitors/exatn/ExatnVisitor.cpp

+5 −3
Original line number Diff line number Diff line
@@ -489,10 +489,12 @@ void ExatnVisitor<TNQVM_COMPLEX_TYPE>::initialize(std::shared_ptr<AcceleratorBuf 
    });



    //Set up ExaTN computational backend:

    const std::string backend = "cuquantum";

    auto backends = exatn::queryComputationalBackends();

    if(std::find(backends.cbegin(),backends.cend(),"cuquantum") != backends.cend()) {

      exatn::switchComputationalBackend("cuquantum");

      //std::cout << "#MSG(TN-QVM:ExaTN): Switched computational backend to cuQuantum\n"; //debug

    if(std::find(backends.cbegin(),backends.cend(),backend) != backends.cend()) {

      exatn::switchComputationalBackend(backend);

      //std::cout << "#MSG(TN-QVM:ExaTN): Switched computational backend to "

      //          << backend << std::endl << std::flush; //debug

    }

  }