def test_already_mapped_1(self):
"""Circuit not remapped if matches topology.
See: https://github.com/Qiskit/qiskit-terra/issues/342
"""
backend = FakeRueschlikon()
coupling_map = backend.configuration().coupling_map
basis_gates = backend.configuration().basis_gates
qr = QuantumRegister(16, 'qr')
cr = ClassicalRegister(16, 'cr')
qc = QuantumCircuit(qr, cr)
qc.cx(qr[3], qr[14])
qc.cx(qr[5], qr[4])
qc.h(qr[9])
qc.cx(qr[9], qr[8])
qc.x(qr[11])
qc.cx(qr[3], qr[4])
qc.cx(qr[12], qr[11])
qc.cx(qr[13], qr[4])
qc.measure(qr, cr)
new_qc = transpile(qc,
coupling_map=coupling_map,
basis_gates=basis_gates,
initial_layout=Layout.generate_trivial_layout(qr))
cx_qubits = [
qargs for (gate, qargs, _) in new_qc.data if gate.name == "cx"
]
cx_qubits_physical = [[ctrl.index, tgt.index]
for [ctrl, tgt] in cx_qubits]
self.assertEqual(sorted(cx_qubits_physical),
[[3, 4], [3, 14], [5, 4], [9, 8], [12, 11], [13, 4]])
def run(self, dag):
"""
If `dag` is mapped and the direction is correct the property
`is_direction_mapped` is set to True (or to False otherwise).
Args:
dag (DAGCircuit): DAG to check.
"""
if self.layout is None:
if self.property_set["layout"]:
self.layout = self.property_set["layout"]
else:
self.layout = Layout.generate_trivial_layout(
*dag.qregs.values())
self.property_set['is_direction_mapped'] = True
edges = self.coupling_map.get_edges()
for gate in dag.twoQ_gates():
physical_q0 = self.layout[gate.qargs[0]]
physical_q1 = self.layout[gate.qargs[1]]
if isinstance(gate.op,
(CXBase, CnotGate)) and (physical_q0,
physical_q1) not in edges:
self.property_set['is_direction_mapped'] = False
return
def test_final_measurement_barrier_for_devices(self, mock_pass):
"""Verify BarrierBeforeFinalMeasurements pass is called in default pipeline for devices."""
circ = QuantumCircuit.from_qasm_file(self._get_resource_path('example.qasm', Path.QASMS))
layout = Layout.generate_trivial_layout(*circ.qregs)
transpile(circ, coupling_map=FakeRueschlikon().configuration().coupling_map,
initial_layout=layout)
self.assertTrue(mock_pass.called)
def swap_decompose(self, dag: DAGCircuit, node: DAGOpNode,
current_layout: Layout,
swap_strategy: SwapStrategy) -> DAGCircuit:
"""Take an instance of :class:`.Commuting2qBlock` and map it to the coupling map.
The mapping is done with the swap strategy.
Args:
dag: The dag which contains the :class:`.Commuting2qBlock` we route.
node: A node whose operation is a :class:`.Commuting2qBlock`.
current_layout: The layout before the swaps are applied. This function will
modify the layout so that subsequent gates can be properly composed on the dag.
swap_strategy: The swap strategy used to decompose the node.
Returns:
A dag that is compatible with the coupling map where swap gates have been added
to map the gates in the :class:`.Commuting2qBlock` to the hardware.
"""
trivial_layout = Layout.generate_trivial_layout(*dag.qregs.values())
gate_layers = self._make_op_layers(dag, node.op, current_layout,
swap_strategy)
# Iterate over and apply gate layers
max_distance = max(gate_layers.keys())
circuit_with_swap = QuantumCircuit(len(dag.qubits))
for i in range(max_distance + 1):
# Get current layer and replace the problem indices j,k by the corresponding
# positions in the coupling map. The current layer corresponds
# to all the gates that can be applied at the ith swap layer.
current_layer = {}
for (j, k), local_gate in gate_layers.get(i, {}).items():
current_layer[self._position_in_cmap(
j, k, current_layout)] = local_gate
# Not all gates that are applied at the ith swap layer can be applied at the same
# time. We therefore greedily build sub-layers.
sub_layers = self._build_sub_layers(current_layer)
# Apply sub-layers
for sublayer in sub_layers:
for edge, local_gate in sublayer.items():
circuit_with_swap.append(local_gate, edge)
# Apply SWAP gates
if i < max_distance:
for swap in swap_strategy.swap_layer(i):
(j, k) = [
trivial_layout.get_physical_bits()[vertex]
for vertex in swap
]
circuit_with_swap.swap(j, k)
current_layout.swap(j, k)
return circuit_to_dag(circuit_with_swap)
def run(self, dag):
"""Run one pass of the lookahead mapper on the provided DAG.
Args:
dag (DAGCircuit): the directed acyclic graph to be mapped
Returns:
DAGCircuit: A dag mapped to be compatible with the coupling_map in
the property_set.
Raises:
TranspilerError: if the coupling map or the layout are not
compatible with the DAG
"""
coupling_map = self._coupling_map
ordered_virtual_gates = list(dag.serial_layers())
if self.initial_layout is None:
if self.property_set["layout"]:
self.initial_layout = self.property_set["layout"]
else:
self.initial_layout = Layout.generate_trivial_layout(
*dag.qregs.values())
if len(dag.qubits()) != len(self.initial_layout):
raise TranspilerError(
'The layout does not match the amount of qubits in the DAG')
if len(self._coupling_map.physical_qubits) != len(self.initial_layout):
raise TranspilerError(
"Mappers require to have the layout to be the same size as the coupling map"
)
mapped_gates = []
layout = self.initial_layout.copy()
gates_remaining = ordered_virtual_gates.copy()
while gates_remaining:
best_step = _search_forward_n_swaps(layout, gates_remaining,
coupling_map)
layout = best_step['layout']
gates_mapped = best_step['gates_mapped']
gates_remaining = best_step['gates_remaining']
mapped_gates.extend(gates_mapped)
# Preserve input DAG's name, regs, wire_map, etc. but replace the graph.
mapped_dag = _copy_circuit_metadata(dag, coupling_map)
for node in mapped_gates:
mapped_dag.apply_operation_back(op=node.op,
qargs=node.qargs,
cargs=node.cargs)
return mapped_dag
def run(self, dag):
"""
Flips the cx nodes to match the directed coupling map.
Args:
dag (DAGCircuit): DAG to map.
Returns:
DAGCircuit: The rearranged dag for the coupling map
Raises:
TranspilerError: If the circuit cannot be mapped just by flipping the
cx nodes.
"""
new_dag = DAGCircuit()
if self.layout is None:
# LegacySwap renames the register in the DAG and does not match the property set
self.layout = Layout.generate_trivial_layout(*dag.qregs.values())
for layer in dag.serial_layers():
subdag = layer['graph']
for cnot_node in subdag.named_nodes('cx', 'CX'):
control = cnot_node.qargs[0]
target = cnot_node.qargs[1]
physical_q0 = self.layout[control]
physical_q1 = self.layout[target]
if self.coupling_map.distance(physical_q0, physical_q1) != 1:
raise TranspilerError(
'The circuit requires a connection between physical '
'qubits %s and %s' % (physical_q0, physical_q1))
if (physical_q0,
physical_q1) not in self.coupling_map.get_edges():
# A flip needs to be done
# Create the involved registers
if control[0] not in subdag.qregs.values():
subdag.add_qreg(control[0])
if target[0] not in subdag.qregs.values():
subdag.add_qreg(target[0])
# Add H gates around
subdag.apply_operation_back(HGate(), [target], [])
subdag.apply_operation_back(HGate(), [control], [])
subdag.apply_operation_front(HGate(), [target], [])
subdag.apply_operation_front(HGate(), [control], [])
# Flips the CX
cnot_node.qargs[0], cnot_node.qargs[1] = target, control
new_dag.extend_back(subdag)
return new_dag
def test_final_measurement_barrier_for_devices(self):
"""Verify BarrierBeforeFinalMeasurements pass is called in default pipeline for devices."""
qasm_dir = os.path.join(
os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
'qasm')
circ = QuantumCircuit.from_qasm_file(
os.path.join(qasm_dir, 'example.qasm'))
layout = Layout.generate_trivial_layout(*circ.qregs)
orig_pass = BarrierBeforeFinalMeasurements()
with patch.object(BarrierBeforeFinalMeasurements, 'run', wraps=orig_pass.run) as mock_pass:
transpile(circ, coupling_map=FakeRueschlikon().configuration().coupling_map,
initial_layout=layout)
self.assertTrue(mock_pass.called)
def run(self, dag):
"""
Pick a layout by assigning n circuit qubits to device qubits 0, .., n-1.
Args:
dag (DAGCircuit): DAG to find layout for.
Raises:
TranspilerError: if dag wider than self.coupling_map
"""
num_dag_qubits = sum([qreg.size for qreg in dag.qregs.values()])
if num_dag_qubits > self.coupling_map.size():
raise TranspilerError('Number of qubits greater than device.')
self.property_set['layout'] = Layout.generate_trivial_layout(*dag.qregs.values())
def test_do_not_run_cxdirection_with_symmetric_cm(self):
"""When the coupling map is symmetric, do not run CXDirection."""
circ = QuantumCircuit.from_qasm_file(self._get_resource_path('example.qasm', Path.QASMS))
layout = Layout.generate_trivial_layout(*circ.qregs)
coupling_map = []
for node1, node2 in FakeRueschlikon().configuration().coupling_map:
coupling_map.append([node1, node2])
coupling_map.append([node2, node1])
cxdir_pass = CXDirection(CouplingMap(coupling_map))
with unittest.mock.patch.object(CXDirection, 'run', wraps=cxdir_pass.run) as mock_pass:
transpile(circ, coupling_map=coupling_map, initial_layout=layout)
self.assertFalse(mock_pass.called)
def test_ignore_initial_layout(self):
"""Ignoring initial layout even when it is supplied"""
coupling = CouplingMap([[0, 1], [0, 2]])
circuit = QuantumCircuit(3)
circuit.cx(1, 2)
property_set = {"layout": Layout.generate_trivial_layout(*circuit.qubits)}
actual = BIPMapping(coupling)(circuit, property_set)
q = QuantumRegister(3, name="q")
expected = QuantumCircuit(q)
expected.cx(q[0], q[1])
self.assertEqual(expected, actual)
def test_parameterized_circuit_for_device(self):
"""Verify that a parameterized circuit can be transpiled for a device backend."""
qr = QuantumRegister(2, name='qr')
qc = QuantumCircuit(qr)
theta = Parameter('theta')
qc.rz(theta, qr[0])
transpiled_qc = transpile(qc, backend=FakeMelbourne(),
initial_layout=Layout.generate_trivial_layout(qr))
qr = QuantumRegister(14, 'q')
expected_qc = QuantumCircuit(qr, global_phase=-1 * theta / 2.0)
expected_qc.append(U1Gate(theta), [qr[0]])
self.assertEqual(expected_qc, transpiled_qc)
def test_do_not_run_gatedirection_with_symmetric_cm(self):
"""When the coupling map is symmetric, do not run GateDirection."""
qasm_dir = os.path.join(
os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
'qasm')
circ = QuantumCircuit.from_qasm_file(
os.path.join(qasm_dir, 'example.qasm'))
layout = Layout.generate_trivial_layout(*circ.qregs)
coupling_map = []
for node1, node2 in FakeRueschlikon().configuration().coupling_map:
coupling_map.append([node1, node2])
coupling_map.append([node2, node1])
orig_pass = GateDirection(CouplingMap(coupling_map))
with patch.object(GateDirection, 'run', wraps=orig_pass.run) as mock_pass:
transpile(circ, coupling_map=coupling_map, initial_layout=layout)
self.assertFalse(mock_pass.called)
def test_parameter_expression_circuit_for_device(self):
"""Verify that a circuit including expressions of parameters can be
transpiled for a device backend."""
qr = QuantumRegister(2, name='qr')
qc = QuantumCircuit(qr)
theta = Parameter('theta')
square = theta * theta
qc.rz(square, qr[0])
transpiled_qc = transpile(qc, backend=FakeMelbourne(),
initial_layout=Layout.generate_trivial_layout(qr))
qr = QuantumRegister(14, 'q')
expected_qc = QuantumCircuit(qr, global_phase=-1 * square / 2.0)
expected_qc.append(U1Gate(square), [qr[0]])
self.assertEqual(expected_qc, transpiled_qc)
def run(self, dag):
"""
Run the StochasticSwap pass on `dag`.
Args:
dag (DAGCircuit): DAG to map.
Returns:
DAGCircuit: A mapped DAG.
Raises:
TranspilerError: if the coupling map or the layout are not
compatible with the DAG
"""
if self.initial_layout is None:
if self.property_set["layout"]:
self.initial_layout = self.property_set["layout"]
else:
self.initial_layout = Layout.generate_trivial_layout(
*dag.qregs.values())
if len(dag.qubits()) != len(self.initial_layout):
raise TranspilerError(
'The layout does not match the amount of qubits in the DAG')
if len(self.coupling_map.physical_qubits) != len(self.initial_layout):
raise TranspilerError(
"Mappers require to have the layout to be the same size as the coupling map"
)
self.input_layout = self.initial_layout.copy()
self.qregs = dag.qregs
if self.seed is None:
self.seed = np.random.randint(0, np.iinfo(np.int32).max)
self.rng = np.random.RandomState(self.seed)
logger.debug("StochasticSwap RandomState seeded with seed=%s",
self.seed)
new_dag = self._mapper(dag, self.coupling_map, trials=self.trials)
# self.property_set["layout"] = self.initial_layout
return new_dag
def run(self, dag):
"""
If `dag` is mapped to `coupling_map`, the property
`is_swap_mapped` is set to True (or to False otherwise).
Args:
dag (DAGCircuit): DAG to map.
"""
if self.layout is None:
if self.property_set["layout"]:
self.layout = self.property_set["layout"]
else:
self.layout = Layout.generate_trivial_layout(
*dag.qregs.values())
self.property_set['is_swap_mapped'] = True
for gate in dag.twoQ_gates():
physical_q0 = self.layout[gate.qargs[0]]
physical_q1 = self.layout[gate.qargs[1]]
if self.coupling_map.distance(physical_q0, physical_q1) != 1:
self.property_set['is_swap_mapped'] = False
return
def run(self, dag: DAGCircuit) -> DAGCircuit:
"""Run the pass by decomposing the nodes it applies on.
Args:
dag: The dag to which we will add swaps.
Returns:
A dag where swaps have been added for the intended gate type.
Raises:
TranspilerError: If the swap strategy was not given at init time and there is
no swap strategy in the property set.
TranspilerError: If the quantum circuit contains more than one qubit register.
TranspilerError: If there are qubits that are not contained in the quantum register.
"""
if self._swap_strategy is None:
swap_strategy = self.property_set["swap_strategy"]
if swap_strategy is None:
raise TranspilerError(
"No swap strategy given at init or in the property set.")
else:
swap_strategy = self._swap_strategy
if len(dag.qregs) != 1:
raise TranspilerError(
f"{self.__class__.__name__} runs on circuits with one quantum register."
)
if len(dag.qubits) != next(iter(dag.qregs.values())).size:
raise TranspilerError(
"Circuit has qubits not contained in the qubit register.")
new_dag = dag.copy_empty_like()
current_layout = Layout.generate_trivial_layout(*dag.qregs.values())
# Used to keep track of nodes that do not decompose using swap strategies.
accumulator = new_dag.copy_empty_like()
self._bit_indices = {
bit: index
for index, bit in enumerate(dag.qubits)
}
for node in dag.topological_op_nodes():
if isinstance(node.op, Commuting2qBlock):
# Check that the swap strategy creates enough connectivity for the node.
self._check_edges(node, swap_strategy)
# Compose any accumulated non-swap strategy gates to the dag
accumulator = self._compose_non_swap_nodes(
accumulator, current_layout, new_dag)
# Decompose the swap-strategy node and add to the dag.
new_dag.compose(
self.swap_decompose(dag, node, current_layout,
swap_strategy))
else:
accumulator.apply_operation_back(node.op, node.qargs,
node.cargs)
self._compose_non_swap_nodes(accumulator, current_layout, new_dag)
return new_dag
def run(self, dag):
"""
Runs the BasicSwap pass on `dag`.
Args:
dag (DAGCircuit): DAG to map.
Returns:
DAGCircuit: A mapped DAG.
Raises:
TranspilerError: if the coupling map or the layout are not
compatible with the DAG
"""
new_dag = DAGCircuit()
if self.initial_layout is None:
if self.property_set["layout"]:
self.initial_layout = self.property_set["layout"]
else:
self.initial_layout = Layout.generate_trivial_layout(
*dag.qregs.values())
if len(dag.qubits()) != len(self.initial_layout):
raise TranspilerError(
'The layout does not match the amount of qubits in the DAG')
if len(self.coupling_map.physical_qubits) != len(self.initial_layout):
raise TranspilerError(
"Mappers require to have the layout to be the same size as the coupling map"
)
current_layout = self.initial_layout.copy()
for layer in dag.serial_layers():
subdag = layer['graph']
for gate in subdag.twoQ_gates():
physical_q0 = current_layout[gate.qargs[0]]
physical_q1 = current_layout[gate.qargs[1]]
if self.coupling_map.distance(physical_q0, physical_q1) != 1:
# Insert a new layer with the SWAP(s).
swap_layer = DAGCircuit()
path = self.coupling_map.shortest_undirected_path(
physical_q0, physical_q1)
for swap in range(len(path) - 2):
connected_wire_1 = path[swap]
connected_wire_2 = path[swap + 1]
qubit_1 = current_layout[connected_wire_1]
qubit_2 = current_layout[connected_wire_2]
# create qregs
for qreg in current_layout.get_registers():
if qreg not in swap_layer.qregs.values():
swap_layer.add_qreg(qreg)
# create the swap operation
swap_layer.apply_operation_back(
SwapGate(), qargs=[qubit_1, qubit_2], cargs=[])
# layer insertion
edge_map = current_layout.combine_into_edge_map(
self.initial_layout)
new_dag.compose_back(swap_layer, edge_map)
# update current_layout
for swap in range(len(path) - 2):
current_layout.swap(path[swap], path[swap + 1])
edge_map = current_layout.combine_into_edge_map(
self.initial_layout)
new_dag.extend_back(subdag, edge_map)
return new_dag
