def simplify_circuit(circuit: 'cirq.Circuit') -> None:
"""Simplifies and optimizes the given circuit (in place).
Args:
circuit (cirq.Circuit): Circuit to simplify. Modified.
Currently it
* merges any neighboring gates belonging to the same one-parameter family
* merges all one-qubit rotations into phased X rotations followed by Z rotations
* pushes the Z rotations towards the end of the circuit as far as possible
* drops any empty Moments
"""
# the optimizers cause the immediate decomposition of any gates they insert into the Circuit
for _ in range(7):
# FIXME This sucks, but it seems that Cirq optimizers have no way of communicating
# if they actually made any changes to the Circuit, so we run a fixed number of iterations.
# Ideally we would keep doing this until the circuit hits a fixed point and no further changes are made.
# all mergeable 2-qubit gates are merged
MergeOneParameterGroupGates().optimize_circuit(circuit)
optimizers.merge_single_qubit_gates_into_phased_x_z(circuit)
# all z rotations are pushed past the first two-qubit gate following them
IQMEjectZ(eject_parameterized=True).optimize_circuit(circuit)
optimizers.DropEmptyMoments().optimize_circuit(circuit)
DropRZBeforeMeasurement().optimize_circuit(circuit)
optimizers.DropEmptyMoments().optimize_circuit(circuit)
DecomposeGatesFinal().optimize_circuit(circuit)
def convert_circuit(self, circuit: circuits.Circuit) -> circuits.Circuit:
new_circuit = circuits.Circuit()
for moment in circuit:
for op in moment.operations:
new_circuit.append(self.convert_one(op))
optimizers.merge_single_qubit_gates_into_phased_x_z(new_circuit)
return new_circuit
def _get_sycamore_optimizers(
tolerance: float, tabulation: Optional[GateTabulation]
) -> List[Callable[['cirq.Circuit'], None]]:
return [
ConvertToSycamoreGates(tabulation=tabulation).optimize_circuit,
lambda c: optimizers.merge_single_qubit_gates_into_phased_x_z(
c, tolerance),
*_get_common_cleanup_optimizers(tolerance=tolerance),
]
def _get_sqrt_iswap_optimizers(
tolerance: float, tabulation: Optional[GateTabulation]
) -> List[Callable[['cirq.Circuit'], None]]:
if tabulation is not None:
# coverage: ignore
raise ValueError("Gate tabulation not supported for sqrt_iswap")
return [
ConvertToSqrtIswapGates().optimize_circuit,
lambda c: optimizers.merge_single_qubit_gates_into_phased_x_z(
c, tolerance),
*_get_common_cleanup_optimizers(tolerance=tolerance),
]
def _get_xmon_optimizers_part_cz(
tolerance: float, tabulation: Optional[GateTabulation]
) -> List[Callable[['cirq.Circuit'], None]]:
if tabulation is not None:
# coverage: ignore
raise ValueError("Gate tabulation not supported for xmon")
return [
convert_to_xmon_gates.ConvertToXmonGates().optimize_circuit,
optimizers.MergeInteractions(tolerance=tolerance,
allow_partial_czs=True).optimize_circuit,
lambda c: optimizers.merge_single_qubit_gates_into_phased_x_z(
c, tolerance),
*_get_common_cleanup_optimizers(tolerance=tolerance),
]
def _merge_rots(c: 'cirq.Circuit'):
return optimizers.merge_single_qubit_gates_into_phased_x_z(c, _TOLERANCE)