Quellcode für qiskit.transpiler.passes.basis.decompose

# This code is part of Qiskit.
# (C) Copyright IBM 2017, 2018.
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

"""Expand a gate in a circuit using its decomposition rules."""
from typing import Type, Union, List, Optional
from fnmatch import fnmatch

from qiskit.transpiler.basepasses import TransformationPass
from qiskit.dagcircuit.dagcircuit import DAGCircuit
from qiskit.converters.circuit_to_dag import circuit_to_dag
from qiskit.circuit.gate import Gate

[Doku]class Decompose(TransformationPass): """Expand a gate in a circuit using its decomposition rules.""" def __init__( self, gates_to_decompose: Optional[Union[Type[Gate], List[Type[Gate]], List[str], str]] = None, ) -> None: """Decompose initializer. Args: gates_to_decompose: optional subset of gates to be decomposed, identified by gate label, name or type. Defaults to all gates. """ super().__init__() self.gates_to_decompose = gates_to_decompose
[Doku] def run(self, dag: DAGCircuit) -> DAGCircuit: """Run the Decompose pass on `dag`. Args: dag: input dag. Returns: output dag where ``gate`` was expanded. """ # Walk through the DAG and expand each non-basis node for node in dag.op_nodes(): if self._should_decompose(node): if getattr(node.op, "definition", None) is None: continue # TODO: allow choosing among multiple decomposition rules rule = node.op.definition.data if ( len(rule) == 1 and len(node.qargs) == len(rule[0].qubits) == 1 # to preserve gate order and len(node.cargs) == len(rule[0].clbits) == 0 ): if node.op.definition.global_phase: dag.global_phase += node.op.definition.global_phase dag.substitute_node(node, rule[0].operation, inplace=True) else: decomposition = circuit_to_dag(node.op.definition) dag.substitute_node_with_dag(node, decomposition) return dag
def _should_decompose(self, node) -> bool: """Call a decomposition pass on this circuit, to decompose one level (shallow decompose).""" if self.gates_to_decompose is None: # check if no gates given return True if not isinstance(self.gates_to_decompose, list): gates = [self.gates_to_decompose] else: gates = self.gates_to_decompose strings_list = [s for s in gates if isinstance(s, str)] gate_type_list = [g for g in gates if isinstance(g, type)] if ( getattr(node.op, "label", None) is not None and node.op.label != "" and ( # check if label or label wildcard is given node.op.label in gates or any(fnmatch(node.op.label, p) for p in strings_list) ) ): return True elif node.name in gates or any( # check if name or name wildcard is given fnmatch(node.name, p) for p in strings_list ): return True elif any(isinstance(node.op, op) for op in gate_type_list): # check if Gate type given return True else: return False