def run(self, dag):
"""Run the CXDirection pass on `dag`.
Flips the cx nodes to match the directed coupling map. Modifies the
input dag.
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.
"""
cmap_edges = set(self.coupling_map.get_edges())
if len(dag.qregs) > 1:
raise TranspilerError(
'CXDirection expects a single qreg input DAG,'
'but input DAG had qregs: {}.'.format(dag.qregs))
trivial_layout = Layout.generate_trivial_layout(*dag.qregs.values())
for cnot_node in dag.named_nodes('cx', 'CX'):
control = cnot_node.qargs[0]
target = cnot_node.qargs[1]
physical_q0 = trivial_layout[control]
physical_q1 = trivial_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 cmap_edges:
# A flip needs to be done
# Create the replacement dag and associated register.
sub_dag = DAGCircuit()
sub_qr = QuantumRegister(2)
sub_dag.add_qreg(sub_qr)
# Add H gates before
sub_dag.apply_operation_back(U2Gate(0, pi), [sub_qr[0]], [])
sub_dag.apply_operation_back(U2Gate(0, pi), [sub_qr[1]], [])
# Flips the cx
sub_dag.apply_operation_back(CXGate(), [sub_qr[1], sub_qr[0]],
[])
# Add H gates after
sub_dag.apply_operation_back(U2Gate(0, pi), [sub_qr[0]], [])
sub_dag.apply_operation_back(U2Gate(0, pi), [sub_qr[1]], [])
dag.substitute_node_with_dag(cnot_node, sub_dag)
return dag
def _circuit_u321(theta, phi, lam, phase, simplify=True, atol=DEFAULT_ATOL):
qr = QuantumRegister(1, "qr")
circuit = QuantumCircuit(qr, global_phase=phase)
if not simplify:
atol = -1.0
if abs(theta) < atol:
tot = _mod_2pi(phi + lam, atol)
if abs(tot) > atol:
circuit._append(U1Gate(tot), [qr[0]], [])
elif abs(theta - np.pi / 2) < atol:
circuit._append(U2Gate(_mod_2pi(phi, atol), _mod_2pi(lam, atol)), [qr[0]], [])
else:
circuit._append(U3Gate(theta, _mod_2pi(phi, atol), _mod_2pi(lam, atol)), [qr[0]], [])
return circuit
def test_optimize_u3_to_u2(self):
"""U3(pi/2, 0, pi/4) -> U2(0, pi/4). Basis [u1, u2, u3]."""
qr = QuantumRegister(2, 'qr')
circuit = QuantumCircuit(qr)
circuit.append(U3Gate(np.pi / 2, 0, np.pi / 4), [qr[0]])
expected = QuantumCircuit(qr)
expected.append(U2Gate(0, np.pi / 4), [qr[0]])
basis = ['u1', 'u2', 'u3']
passmanager = PassManager()
passmanager.append(BasisTranslator(sel, basis))
passmanager.append(Optimize1qGatesDecomposition(basis))
result = passmanager.run(circuit)
self.assertEqual(expected, result)
def test_optimize_u3_to_u2(self):
"""U3(pi/2, 0, pi/4) -> U2(0, pi/4). Basis [u1, u2, u3]."""
qr = QuantumRegister(2, "qr")
circuit = QuantumCircuit(qr)
circuit.append(U3Gate(np.pi / 2, 0, np.pi / 4), [qr[0]])
expected = QuantumCircuit(qr)
expected.append(U2Gate(0, np.pi / 4), [qr[0]])
basis = ["u1", "u2", "u3"]
passmanager = PassManager()
passmanager.append(BasisTranslator(sel, basis))
passmanager.append(Optimize1qGatesDecomposition(basis))
result = passmanager.run(circuit)
self.assertEqual(expected, result)
msg = f"expected:\n{expected}\nresult:\n{result}"
self.assertEqual(expected, result, msg=msg)
def _circuit_u321(theta,
phi,
lam,
phase,
simplify=True,
atol=DEFAULT_ATOL):
rtol = 1e-9 # default is 1e-5, too far from atol=1e-12
circuit = QuantumCircuit(1, global_phase=phase)
if simplify and (np.isclose(theta, 0.0, atol=atol, rtol=rtol)):
if not np.isclose(
phi + lam, [0.0, 2 * np.pi], atol=atol, rtol=rtol).any():
circuit.append(U1Gate(_mod2pi(phi + lam)), [0])
elif simplify and np.isclose(theta, np.pi / 2, atol=atol, rtol=rtol):
circuit.append(U2Gate(phi, lam), [0])
else:
circuit.append(U3Gate(theta, phi, lam), [0])
return circuit
def _circuit_u321(theta,
phi,
lam,
phase,
simplify=True,
atol=DEFAULT_ATOL):
rtol = 1e-9 # default is 1e-5, too far from atol=1e-12
qr = QuantumRegister(1, 'qr')
circuit = QuantumCircuit(qr, global_phase=phase)
if simplify and (math.isclose(theta, 0.0, abs_tol=atol, rel_tol=rtol)):
phi_lam = phi + lam
if not (math.isclose(phi_lam, 0.0, abs_tol=atol, rel_tol=rtol) or
math.isclose(phi_lam, 2*np.pi, abs_tol=atol, rel_tol=rtol)):
circuit._append(U1Gate(_mod2pi(phi+lam)), [qr[0]], [])
elif simplify and math.isclose(theta, np.pi/2, abs_tol=atol, rel_tol=rtol):
circuit._append(U2Gate(phi, lam), [qr[0]], [])
else:
circuit._append(U3Gate(theta, phi, lam), [qr[0]], [])
return circuit
from qiskit.circuit import EquivalenceLibrary, Parameter, QuantumCircuit, QuantumRegister
from qiskit.circuit.library.standard_gates import U2Gate, U3Gate, HGate, U1Gate, CCXGate, TdgGate, TGate, RZGate, CXGate
from qiskit.qasm import pi
eq_lib = EquivalenceLibrary()
theta = Parameter('theta')
phi = Parameter('phi')
lamda = Parameter('lamda')
u3 = U3Gate(theta, phi, lamda)
u2 = U2Gate(theta, phi)
u1 = U1Gate(theta)
ccx = CCXGate()
q = QuantumRegister(1, 'q')
equiv_u3 = QuantumCircuit(q)
equiv_u3.append(RZGate(phi+(pi/2)), [q[0]], [])
equiv_u3.append(HGate(),[q[0]], [] )
equiv_u3.append(RZGate(theta),[q[0]], [])
equiv_u3.append(HGate(), [q[0]], [])
equiv_u3.append(RZGate(lamda-(pi/2)),[q[0]], 0)
eq_lib.add_equivalence(u3, equiv_u3)
q = QuantumRegister(1, 'q')
equiv_u2 = QuantumCircuit(q)
equiv_u2.append(RZGate(theta+(pi/2)), [q[0]], [])
equiv_u2.append(HGate(),[q[0]], [] )
equiv_u2.append(RZGate(pi/2),[q[0]], [])
equiv_u2.append(HGate(), [q[0]], [])