def test_direction_flip(self):
"""
qr0:----.----
|
qr1:---(+)---
Coupling map: [0] -> [1]
qr0:---(+)---
|
qr1:----.----
"""
qr = QuantumRegister(2, 'qr')
circuit = QuantumCircuit(qr)
circuit.cx(qr[1], qr[0])
coupling = Coupling({0: [1]})
dag = circuit_to_dag(circuit)
expected = QuantumCircuit(qr)
expected.h(qr[0])
expected.h(qr[1])
expected.cx(qr[0], qr[1])
expected.h(qr[0])
expected.h(qr[1])
pass_ = DirectionMapper(coupling)
after = pass_.run(dag)
self.assertEqual(circuit_to_dag(expected), after)
def test_direction_correct(self):
""" The CX is in the right direction
qr0:---(+)---
|
qr1:----.----
Coupling map: [0] -> [1]
"""
qr = QuantumRegister(2, 'qr')
circuit = QuantumCircuit(qr)
circuit.cx(qr[0], qr[1])
coupling = Coupling({0: [1]})
dag = circuit_to_dag(circuit)
pass_ = DirectionMapper(coupling)
after = pass_.run(dag)
self.assertEqual(dag, after)
def test_direction_error(self):
"""
qr0:---------
qr1:---(+)---
|
qr2:----.----
Coupling map: [2] <- [0] -> [1]
"""
qr = QuantumRegister(3, 'qr')
circuit = QuantumCircuit(qr)
circuit.cx(qr[1], qr[2])
coupling = Coupling({0: [2, 1]})
dag = circuit_to_dag(circuit)
pass_ = DirectionMapper(coupling)
with self.assertRaises(MapperError):
pass_.run(dag)
def test_no_cnots(self):
""" Trivial map in a circuit without entanglement
qr0:---[H]---
qr1:---[H]---
qr2:---[H]---
Coupling map: None
"""
qr = QuantumRegister(3, 'qr')
circuit = QuantumCircuit(qr)
circuit.h(qr)
coupling = Coupling()
dag = circuit_to_dag(circuit)
pass_ = DirectionMapper(coupling)
after = pass_.run(dag)
self.assertEqual(dag, after)
def test_flip_with_measure(self):
"""
qr0: -(+)-[m]-
| |
qr1: --.---|--
|
cr0: ------.--
Coupling map: [0] -> [1]
qr0: -[H]--.--[H]-[m]-
| |
qr1: -[H]-(+)-[H]--|--
|
cr0: --------------.--
"""
qr = QuantumRegister(2, 'qr')
cr = ClassicalRegister(1, 'cr')
circuit = QuantumCircuit(qr, cr)
circuit.cx(qr[1], qr[0])
circuit.measure(qr[0], cr[0])
coupling = Coupling({0: [1]})
dag = circuit_to_dag(circuit)
expected = QuantumCircuit(qr, cr)
expected.h(qr[0])
expected.h(qr[1])
expected.cx(qr[0], qr[1])
expected.h(qr[0])
expected.h(qr[1])
expected.measure(qr[0], cr[0])
pass_ = DirectionMapper(coupling)
after = pass_.run(dag)
self.assertEqual(circuit_to_dag(expected), after)