Source code for qbraid.transforms.pytket.ionq

# Copyright (C) 2024 qBraid
#
# This file is part of the qBraid-SDK
#
# The qBraid-SDK is free software released under the GNU General Public License v3
# or later. You can redistribute and/or modify it under the terms of the GPL v3.
# See the LICENSE file in the project root or <https://www.gnu.org/licenses/gpl-3.0.html>.
#
# THERE IS NO WARRANTY for the qBraid-SDK, as per Section 15 of the GPL v3.

"""
Module for converting generic quantum circuits to basis gate set compatible with IonQ devices.

"""

# pylint: disable=no-name-in-module,no-member

from typing import TYPE_CHECKING

import pytket

try:
    # pytket >= 1.22
    from pytket.circuit_library import TK1_to_RzRx  # type: ignore
except (ModuleNotFoundError, ImportError):  # prama: no cover
    try:
        # pytket >1.18,<1.22
        from pytket.circuit_library import _TK1_to_RzRx as TK1_to_RzRx  # type: ignore
    except (ModuleNotFoundError, ImportError):
        # pytket <= 1.18
        from pytket._tket.circuit._library import _TK1_to_RzRx as TK1_to_RzRx  # type: ignore

from pytket.passes import RebaseCustom
from pytket.predicates import (
    CompilationUnit,
    GateSetPredicate,
    MaxNQubitsPredicate,
    NoClassicalControlPredicate,
    NoFastFeedforwardPredicate,
    NoMidMeasurePredicate,
    NoSymbolsPredicate,
)

from qbraid.transforms.exceptions import CompilationError

if TYPE_CHECKING:
    import pytket.circuit

HARMONY_MAX_QUBITS = 11

ionq_gates = {
    pytket.circuit.OpType.X,
    pytket.circuit.OpType.Y,
    pytket.circuit.OpType.Z,
    pytket.circuit.OpType.Rx,
    pytket.circuit.OpType.Ry,
    pytket.circuit.OpType.Rz,
    pytket.circuit.OpType.H,
    pytket.circuit.OpType.S,
    pytket.circuit.OpType.Sdg,
    pytket.circuit.OpType.T,
    pytket.circuit.OpType.Tdg,
    pytket.circuit.OpType.V,
    pytket.circuit.OpType.Vdg,
    pytket.circuit.OpType.Measure,
    pytket.circuit.OpType.noop,
    pytket.circuit.OpType.SWAP,
    pytket.circuit.OpType.CX,
    pytket.circuit.OpType.ZZPhase,
    pytket.circuit.OpType.XXPhase,
    pytket.circuit.OpType.YYPhase,
    pytket.circuit.OpType.ZZMax,
    pytket.circuit.OpType.Barrier,
}

preds = [
    NoClassicalControlPredicate(),
    NoFastFeedforwardPredicate(),
    NoMidMeasurePredicate(),
    NoSymbolsPredicate(),
    GateSetPredicate(ionq_gates),
    MaxNQubitsPredicate(HARMONY_MAX_QUBITS),
]

ionq_rebase_pass = RebaseCustom(
    ionq_gates,
    pytket.Circuit(),  # cx_replacement (irrelevant)
    TK1_to_RzRx,
)  # tk1_replacement




def harmony_transform(circuit: "pytket.circuit.Circuit") -> "pytket.circuit.Circuit":
    """
    Compiles a pytket circuit to gate set supported by IonQ Harmony.

    Args:
        circuit (pytket.circuit.Circuit): The input PyTKET circuit to be transformed.

    Returns:
        pytket.circuit.Circuit: The transformed PyTKET circuit that can run on IonQ Harmony.

    Notes:
        - If the input circuit is a braket Circuit, the function
          transpiles it to a ``pytket.circuit.Circuit`` before compilation.
        - The circuit is transpiled using qBraid's transpiler, if it contains
          any of the following gates::

                CPhaseShift00
                CPhaseShift01
                CPhaseShift10
                CV
                ECR
                GPi
                GPi2
                MS
                PSwap
                Unitary

    """
    cu = CompilationUnit(circuit, preds)
    ionq_rebase_pass.apply(cu)
    if not cu.check_all_predicates():
        raise CompilationError("Circuit cannot be compiled to IonQ Harmony.")
    return cu.circuit