def test_optimizes_single_iswap():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit.from_ops(cirq.ISWAP(a, b))
assert_optimization_not_broken(c)
cg.MergeInteractions().optimize_circuit(c)
assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 2
assert all(cg.XmonGate.is_xmon_op(op) for op in c.all_operations())
def assert_optimization_not_broken(circuit):
"""Check that the unitary matrix for the input circuit is the same (up to
global phase and rounding error) as the unitary matrix of the optimized
circuit."""
u_before = circuit.to_unitary_matrix()
cg.MergeInteractions().optimize_circuit(circuit)
u_after = circuit.to_unitary_matrix()
cirq.testing.assert_allclose_up_to_global_phase(
u_before, u_after, atol=1e-8)
def test_decompose_partial_czs(circuit):
optimizer = cg.MergeInteractions(allow_partial_czs=False)
optimizer.optimize_circuit(circuit)
cz_gates = [op.gate for op in circuit.all_operations()
if cg.XmonGate.is_xmon_op(op) and
isinstance(op.gate, cg.Exp11Gate)]
num_full_cz = sum(1 for cz in cz_gates if cz.half_turns == 1)
num_part_cz = sum(1 for cz in cz_gates if cz.half_turns != 1)
assert num_full_cz == 2
assert num_part_cz == 0
def test_not_decompose_partial_czs():
circuit = cirq.Circuit.from_ops(
cg.Exp11Gate(half_turns=0.1)(*cirq.LineQubit.range(2)),
)
optimizer = cg.MergeInteractions(allow_partial_czs=True)
optimizer.optimize_circuit(circuit)
cz_gates = [op.gate for op in circuit.all_operations()
if cg.XmonGate.is_xmon_op(op) and
isinstance(op.gate, cg.Exp11Gate)]
num_full_cz = sum(1 for cz in cz_gates if cz.half_turns == 1)
num_part_cz = sum(1 for cz in cz_gates if cz.half_turns != 1)
assert num_full_cz == 0
assert num_part_cz == 1
def assert_optimizes(before: cirq.Circuit, expected: cirq.Circuit):
actual = cirq.Circuit(before)
opt = cg.MergeInteractions()
opt.optimize_circuit(actual)
# Ignore differences that would be caught by follow-up optimizations.
followup_optimizations = [
cg.MergeRotations(),
cg.EjectFullW(),
cg.EjectZ(),
cirq.DropNegligible(),
cirq.DropEmptyMoments()
]
for post in followup_optimizations:
post.optimize_circuit(actual)
post.optimize_circuit(expected)
if actual != expected:
# coverage: ignore
print('ACTUAL')
print(actual)
print('EXPECTED')
print(expected)
assert actual == expected