Running test circuits

The driver script for running example circuits (in c++/python) is mqss-cc. After the targets are generated this script is installed within the INSTALL_DIR and should be on the $PATH environment variable fo your bash shell. Check by running the command:

$mqss-cc -h

If nothing prints, run the command eval "$(make set-target-paths)" from the root directory once again.

C++ test circuits

The compilation suite accepts c++ circuits written using cudaq. Following is an example:

#include <cudaq.h>
#include <fstream>
#include <iostream>

template <std::size_t N> struct test {
  auto operator()() __qpu__ {

    // Compile-time sized array like std::array
    cudaq::qarray<N> q;
    x<cudaq::ctrl>(q[0], q[1]);
    x(q[2]);
    rx(2.4, q[1]);

    x<cudaq::ctrl>(q[1], q[0]);
    rx(3.1416, q[1]);

    x<cudaq::ctrl>(q[0], q[1]);
    x(q[1]);
    rx(5.1416, q[1]);

    mz(q[0]);
    mz(q[1]);
  }
};

int main() {
  auto kernel = test<3>{};
  auto counts = cudaq::sample(kernel);
  counts.dump();
  return 0;
}

To run the above test circuit using mqss-cc use the following command:

mqss-cc test.cpp --convert-to=qasm2 --out-dir output/ --passes=CommonGateCancellationPass=mode=CancelGate

The Commutation Optimization pass is applied to commute CNOT and RX gates. The output in this case will be QIR since the emit-qir flag is enabled.

Note: One can use cudaq to write quantum circuits in python. But this is not supported yet within mqss-cc.

Python test circuits

The compilation suite accepts python circuits written using catalyst. Following is an example:

from catalyst import qjit
import pennylane as qml

dev = qml.device("lightning.qubit", wires=3)

@qjit(keep_intermediate=True)
@qml.set_shots(1000)
@qml.qnode(dev)
def circuit_CommuteCNOTRx():
    qml.CNOT(wires=[0, 1])
    qml.PauliX(wires=2)
    qml.RX(2.4, wires=1)

    qml.CNOT(wires=[1, 0])
    qml.RX(3.1416, wires=1)

    qml.CNOT(wires=[0, 1])
    qml.PauliX(wires=1)
    qml.RX(5.1416, wires=1)

    return qml.counts()

mqss-cc test.py --convert-to=qir --function circuit \
           --out-dir output/ --passes=CommonGateCancellationPass=mode=CancelGate

Do Not forget to mention the function to compile afer the --function flag. Refer to Passes for a list of all available MLIR passes.