Commit 92a43356 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Clean up the IQPE implementation 



Removed debug logging and added code comments.

Also, add the two IQPE examples to list of compile tests.

Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent f38804b4

lib/qsim/impls/qsim_impl.cpp

+29 −27
Original line number Diff line number Diff line
@@ -135,10 +135,11 @@ bool IterativeQpeWorkflow::initialize(const HeterogeneousMap &params) { 
std::shared_ptr<CompositeInstruction> IterativeQpeWorkflow::constructQpeCircuit(

    std::shared_ptr<Observable> obs, int k, double omega, bool measure) const {

  auto provider = xacc::getIRProvider("quantum");



  auto kernel = provider->createComposite("__TEMP__QPE__LOOP__");

  const auto nbQubits = obs->nBits();

  // Ancilla qubit is the last one in the register.

  const size_t ancBit = nbQubits;



  // Hadamard on ancilla qubit

  kernel->addInstruction(provider->createInstruction("H", ancBit));
@@ -149,6 +150,7 @@ std::shared_ptr<CompositeInstruction> IterativeQpeWorkflow::constructQpeCircuit( 
  auto trotterCir =

      method.create_ansatz(obs.get(), {{"dt", trotterStepSize}}).circuit;

  // std::cout << "Trotter circ:\n" << trotterCir->toString() << "\n";



  // Controlled-U

  auto ctrlKernel = std::dynamic_pointer_cast<CompositeInstruction>(

      xacc::getService<xacc::Instruction>("C-U"));
@@ -159,15 +161,12 @@ std::shared_ptr<CompositeInstruction> IterativeQpeWorkflow::constructQpeCircuit( 


  // Apply C-U^n

  int power = 1 << (k - 1);

  // std::cout << "Power = " << power << "\n";

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

    for (int j = 0; j < num_steps; ++j) {

  for (int i = 0; i < power * num_steps; ++i) {

    for (int instId = 0; instId < ctrlKernel->nInstructions(); ++instId) {

      // We need to clone the instruction since it'll be repeated.

      kernel->addInstruction(ctrlKernel->getInstruction(instId)->clone());

    }

  }

  }



  // Rz on ancilla qubit

  // Global phase due to identity pauli
@@ -193,11 +192,9 @@ std::shared_ptr<CompositeInstruction> IterativeQpeWorkflow::constructQpeCircuit( 


void IterativeQpeWorkflow::HamOpConverter::fromObservable(Observable *obs) {

  translation = 0.0;



  for (auto &term : obs->getSubTerms()) {

    translation += std::abs(term->coefficient());

  }

  

  stretch = 0.5 / translation;

}
@@ -251,22 +248,26 @@ IterativeQpeWorkflow::execute(const QuantumSimulationModel &model) { 


    qpu->execute(temp_buffer, kernel);

    // temp_buffer->print();



    // Estimate the phase value's bit at this iteration,

    // i.e. get the most-probable measure bit.

    const bool bitResult = [&temp_buffer]() {

      if (!temp_buffer->getMeasurementCounts().empty()) {

        // If the QPU returns bitstrings:

        if (xacc::container::contains(temp_buffer->getMeasurements(), "0")) {

          if (xacc::container::contains(temp_buffer->getMeasurements(), "1")) {

            return temp_buffer->computeMeasurementProbability("1") > temp_buffer->computeMeasurementProbability("0");

          }

          else {

            return temp_buffer->computeMeasurementProbability("1") >

                   temp_buffer->computeMeasurementProbability("0");

          } else {

            return false;

          }

        }

        else {

          assert(xacc::container::contains(temp_buffer->getMeasurements(), "1"));

        } else {

          assert(

              xacc::container::contains(temp_buffer->getMeasurements(), "1"));

          return true;

        }

      }

      else {

      } else {

        // If the QPU returns *expected* Z value:

        return temp_buffer->getExpectationValueZ() < 0.0;

      }

    }();
@@ -274,11 +275,12 @@ IterativeQpeWorkflow::execute(const QuantumSimulationModel &model) { 
    if (bitResult) {

      omega_coef = omega_coef + 0.5;

    }

    // std::cout << "Iter " << iterIdx << ": Result = " << bitResult << "; omega_coef = " << omega_coef << "\n";



    // std::cout << "Iter " << iterIdx << ": Result = " << bitResult << ";

    // omega_coef = " << omega_coef << "\n";

  }



  return { {"phase", omega_coef}, {"energy", ham_converter.computeEnergy(omega_coef)}};

  return {{"phase", omega_coef},

          {"energy", ham_converter.computeEnergy(omega_coef)}};

}



std::shared_ptr<QuantumSimulationWorkflow>

lib/qsim/impls/tests/CMakeLists.txt

+2 −0
Original line number Diff line number Diff line 
add_test(NAME qsim_vqe COMMAND ${CMAKE_BINARY_DIR}/qcor ${CMAKE_CURRENT_SOURCE_DIR}/VqeWithAnsatzCircuit.cpp)

add_test(NAME qsim_trotter COMMAND ${CMAKE_BINARY_DIR}/qcor ${CMAKE_CURRENT_SOURCE_DIR}/TrotterTdWorkflow.cpp)

add_test(NAME qsim_iqpe_simple COMMAND ${CMAKE_BINARY_DIR}/qcor ${CMAKE_CURRENT_SOURCE_DIR}/IterativeQpeSimple.cpp)

add_test(NAME qsim_iqpe_vqe COMMAND ${CMAKE_BINARY_DIR}/qcor ${CMAKE_CURRENT_SOURCE_DIR}/IterativeQpeVqe.cpp)