def assert_optimization_not_broken(circuit: cirq.Circuit, **kwargs):
"""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.unitary(sorted(circuit.all_qubits()))
c_sqrt_iswap = circuit.copy()
with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset",
deadline='v1.0',
count=2):
cirq.MergeInteractionsToSqrtIswap(
**kwargs).optimize_circuit(c_sqrt_iswap)
u_after = c_sqrt_iswap.unitary(sorted(circuit.all_qubits()))
# Not 1e-8 because of some unaccounted accumulated error in some of Cirq's linalg functions
cirq.testing.assert_allclose_up_to_global_phase(u_before,
u_after,
atol=1e-6)
# Also test optimization with SQRT_ISWAP_INV
c_sqrt_iswap_inv = circuit.copy()
with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset",
deadline='v1.0',
count=2):
cirq.MergeInteractionsToSqrtIswap(
use_sqrt_iswap_inv=True).optimize_circuit(c_sqrt_iswap_inv)
u_after2 = c_sqrt_iswap_inv.unitary(sorted(circuit.all_qubits()))
cirq.testing.assert_allclose_up_to_global_phase(u_before,
u_after2,
atol=1e-6)
def test_optimizes_single_inv_sqrt_iswap_require3():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.SQRT_ISWAP_INV(a, b))
assert_optimization_not_broken(c, required_sqrt_iswap_count=3)
cirq.MergeInteractionsToSqrtIswap(
required_sqrt_iswap_count=3).optimize_circuit(c)
assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 3
def assert_optimizes(before: cirq.Circuit, expected: cirq.Circuit, **kwargs):
"""Check that optimizing the circuit ``before`` produces the circuit ``expected``.
The optimized circuit is cleaned up with follow up optimizations to make the
comparison more robust to extra moments or extra gates nearly equal to
identity that don't matter.
Args:
before: The input circuit to optimize.
expected: The expected result of optimization to compare against.
**kwargs: Any extra arguments to pass to the
``MergeInteractionsToSqrtIswap`` constructor.
"""
actual = before.copy()
with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset",
deadline='v1.0',
count=2):
opt = cirq.MergeInteractionsToSqrtIswap(**kwargs)
opt.optimize_circuit(actual)
# Ignore differences that would be caught by follow-up optimizations.
followup_transformers: List[cirq.TRANSFORMER] = [
cirq.merge_single_qubit_gates_to_phased_x_and_z,
cirq.eject_phased_paulis,
cirq.eject_z,
cirq.drop_negligible_operations,
cirq.drop_empty_moments,
]
for transform in followup_transformers:
actual = transform(actual).unfreeze(copy=False)
expected = transform(expected).unfreeze(copy=False)
assert actual == expected, f'ACTUAL {actual} : EXPECTED {expected}'
def test_optimizes_single_iswap_require0():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.CNOT(a, b), cirq.CNOT(a, b)) # Minimum 0 sqrt-iSWAP
assert_optimization_not_broken(c, required_sqrt_iswap_count=0)
cirq.MergeInteractionsToSqrtIswap(
required_sqrt_iswap_count=0).optimize_circuit(c)
assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 0
def assert_optimizes(before: cirq.Circuit, expected: cirq.Circuit, **kwargs):
"""Check that optimizing the circuit ``before`` produces the circuit ``expected``.
The optimized circuit is cleaned up with follow up optimizations to make the
comparison more robust to extra moments or extra gates nearly equal to
identity that don't matter.
Args:
before: The input circuit to optimize.
expected: The expected result of optimization to compare against.
kwargs: Any extra arguments to pass to the
``MergeInteractionsToSqrtIswap`` constructor.
"""
actual = before.copy()
opt = cirq.MergeInteractionsToSqrtIswap(**kwargs)
opt.optimize_circuit(actual)
# Ignore differences that would be caught by follow-up optimizations.
followup_optimizations: List[Callable[[cirq.Circuit], None]] = [
cirq.merge_single_qubit_gates_into_phased_x_z,
cirq.EjectPhasedPaulis().optimize_circuit,
cirq.EjectZ().optimize_circuit,
cirq.DropNegligible().optimize_circuit,
cirq.DropEmptyMoments().optimize_circuit,
]
for post in followup_optimizations:
post(actual)
post(expected)
assert actual == expected, f'ACTUAL {actual} : EXPECTED {expected}'
def test_optimizes_single_iswap_require2_raises():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.SWAP(a, b)) # Minimum 3 sqrt-iSWAP
with pytest.raises(
ValueError,
match='cannot be decomposed into exactly 2 sqrt-iSWAP gates'):
cirq.MergeInteractionsToSqrtIswap(
required_sqrt_iswap_count=2).optimize_circuit(c)
def test_optimizes_single_iswap_require2_raises():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.SWAP(a, b)) # Minimum 3 sqrt-iSWAP
with pytest.raises(ValueError, match='cannot be decomposed into exactly 2 sqrt-iSWAP gates'):
with cirq.testing.assert_deprecated(
"Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
):
cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=2).optimize_circuit(c)
def test_optimizes_single_inv_sqrt_iswap():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.SQRT_ISWAP_INV(a, b))
assert_optimization_not_broken(c)
with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset",
deadline='v1.0',
count=2):
cirq.MergeInteractionsToSqrtIswap().optimize_circuit(c)
assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 1
def test_optimizes_single_iswap_require3():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.ISWAP(a, b)) # Minimum 2 sqrt-iSWAP but 3 possible
assert_optimization_not_broken(c, required_sqrt_iswap_count=3)
with cirq.testing.assert_deprecated(
"Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
):
cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=3).optimize_circuit(c)
assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 3
def test_init_raises():
with pytest.raises(ValueError, match='must be 0, 1, 2, or 3'):
with cirq.testing.assert_deprecated(
"Use cirq.optimize_for_target_gateset", deadline='v1.0',
count=2):
cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=4)
def test_init_raises():
with pytest.raises(ValueError, match='must be 0, 1, 2, or 3'):
cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=4)
def test_optimizes_single_iswap():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.ISWAP(a, b))
assert_optimization_not_broken(c)
cirq.MergeInteractionsToSqrtIswap().optimize_circuit(c)
assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 2
