def test_circular_shift_gate_permutation():
assert (CircularShiftGate(4).permutation(3) == {0: 2, 1: 0, 2: 1})
assert (CircularShiftGate(0).permutation(4) == {0: 0, 1: 1, 2: 2, 3: 3})
assert (CircularShiftGate(2).permutation(5) == {
0: 3,
1: 4,
2: 0,
3: 1,
4: 2
})
def test_circular_shift_gate_decomposition():
qubits = [cirq.NamedQubit(q) for q in 'abcdef']
expander = cirq.ExpandComposite()
circular_shift = CircularShiftGate(1, cirq.CZ)(*qubits[:2])
circuit = cirq.Circuit.from_ops(circular_shift)
expander.optimize_circuit(circuit)
expected_circuit = cirq.Circuit((cirq.Moment((cirq.CZ(*qubits[:2]), )), ))
assert circuit == expected_circuit
no_decomp = lambda op: (isinstance(op, cirq.GateOperation) and op.gate ==
cirq.SWAP)
expander = cirq.ExpandComposite(no_decomp=no_decomp)
circular_shift = CircularShiftGate(3)(*qubits)
circuit = cirq.Circuit.from_ops(circular_shift)
expander.optimize_circuit(circuit)
actual_text_diagram = circuit.to_text_diagram().strip()
expected_text_diagram = """
a: ───────────×───────────
│
b: ───────×───×───×───────
│ │
c: ───×───×───×───×───×───
│ │ │
d: ───×───×───×───×───×───
│ │
e: ───────×───×───×───────
│
f: ───────────×───────────
""".strip()
assert actual_text_diagram == expected_text_diagram
circular_shift = CircularShiftGate(2)(*qubits)
circuit = cirq.Circuit.from_ops(circular_shift)
expander.optimize_circuit(circuit)
actual_text_diagram = circuit.to_text_diagram().strip()
expected_text_diagram = """
a: ───────×───────────────
│
b: ───×───×───×───────────
│ │
c: ───×───×───×───×───────
│ │
d: ───────×───×───×───×───
│ │
e: ───────────×───×───×───
│
f: ───────────────×───────
""".strip()
assert actual_text_diagram == expected_text_diagram
def test_circular_shift_gate_wire_symbols():
qubits = [cirq.NamedQubit(q) for q in 'xyz']
circuit = cirq.Circuit.from_ops(CircularShiftGate(2)(*qubits))
actual_text_diagram = circuit.to_text_diagram().strip()
expected_text_diagram = """
x: ───╲0╱───
│
y: ───╲1╱───
│
z: ───╱2╲───
""".strip()
assert actual_text_diagram == expected_text_diagram
actual_text_diagram = circuit.to_text_diagram(use_unicode_characters=False)
expected_text_diagram = r"""
x: ---\0/---
|
y: ---\1/---
|
z: ---/2\---
""".strip()
assert actual_text_diagram.strip() == expected_text_diagram
def acquaint_and_shift(
parts: Tuple[List['cirq.Qid'], List['cirq.Qid']],
layers: Layers,
acquaintance_size: Optional[int],
swap_gate: 'cirq.Gate',
mapping: Dict[ops.Qid, int],
):
"""Acquaints and shifts a pair of lists of qubits. The first part is
acquainted with every qubit individually in the second part, and vice
versa. Operations are grouped into several layers:
* prior_interstitial: The first layer of acquaintance gates.
* prior: The combination of acquaintance gates and swaps that acquaints
the inner halves.
* intra: The shift gate.
* post: The combination of acquaintance gates and swaps that acquaints
the outer halves.
* posterior_interstitial: The last layer of acquaintance gates.
Args:
parts: The two lists of qubits to acquaint.
layers: The layers to put gates into.
acquaintance_size: The number of qubits to acquaint at a time. If None,
after each pair of parts is shifted the union thereof is
acquainted.
swap_gate: The gate used to swap logical indices.
mapping: The mapping from qubits to logical indices. Used to keep track
of the effect of inside-acquainting swaps.
"""
left_part, right_part = parts
left_size, right_size = len(left_part), len(right_part)
assert not (set(left_part) & set(right_part))
qubits = left_part + right_part
shift = CircularShiftGate(len(qubits), left_size, swap_gate=swap_gate)(*qubits)
if acquaintance_size is None:
layers.intra.append(shift)
layers.post.append(acquaint(*qubits))
shift.gate.update_mapping(mapping, qubits)
elif max(left_size, right_size) != acquaintance_size - 1:
layers.intra.append(shift)
shift.gate.update_mapping(mapping, qubits)
elif acquaintance_size == 2:
layers.prior_interstitial.append(acquaint(*qubits))
layers.intra.append(shift)
shift.gate.update_mapping(mapping, qubits)
else:
# before
if left_size == acquaintance_size - 1:
# right part
pre_acquaintance_gate = acquaint(*qubits[:acquaintance_size])
acquaint_insides(
swap_gate=swap_gate,
acquaintance_gate=pre_acquaintance_gate,
qubits=right_part,
before=True,
layers=layers,
mapping=mapping,
)
if right_size == acquaintance_size - 1:
# left part
pre_acquaintance_gate = acquaint(*qubits[-acquaintance_size:])
acquaint_insides(
swap_gate=swap_gate,
acquaintance_gate=pre_acquaintance_gate,
qubits=left_part[::-1],
before=True,
layers=layers,
mapping=mapping,
)
layers.intra.append(shift)
shift.gate.update_mapping(mapping, qubits)
# after
if (left_size == acquaintance_size - 1) and (right_size > 1):
# right part
post_acquaintance_gate = acquaint(*qubits[-acquaintance_size:])
new_left_part = qubits[right_size - 1 :: -1]
acquaint_insides(
swap_gate=swap_gate,
acquaintance_gate=post_acquaintance_gate,
qubits=new_left_part,
before=False,
layers=layers,
mapping=mapping,
)
if (right_size == acquaintance_size - 1) and (left_size > 1):
# left part
post_acquaintance_gate = acquaint(*qubits[:acquaintance_size])
acquaint_insides(
swap_gate=swap_gate,
acquaintance_gate=post_acquaintance_gate,
qubits=qubits[right_size:],
before=False,
layers=layers,
mapping=mapping,
)
def test_circular_shift_gate_repr():
g = CircularShiftGate(2)
assert repr(g) == 'CircularShiftGate'
def test_circular_shift_gate_eq():
a = CircularShiftGate(1)
b = CircularShiftGate(1)
c = CircularShiftGate(2)
assert a == b
assert a != c
def test_circular_shift_gate_unknown_qubit_count():
g = CircularShiftGate(2)
assert cirq.circuit_diagram_info(g, default=None) is None
def test_circular_shift_gate_init():
g = CircularShiftGate(2)
assert g.shift == 2
g = CircularShiftGate(1, swap_gate=cirq.CZ)
assert g.swap_gate == cirq.CZ
def test_circular_shift_gate_unknown_qubit_count():
g = CircularShiftGate(2)
args = cirq.TextDiagramInfoArgs.UNINFORMED_DEFAULT
assert g.text_diagram_info(args) == NotImplemented
def test_circular_shift_gate_unknown_qubit_count():
g = CircularShiftGate(2)
args = cirq.TextDiagramInfoArgs.UNINFORMED_DEFAULT
assert g.text_diagram_info(args) == NotImplemented
