qiskit.transpiler.preset_passmanagers.level2의 소스 코드
# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 2018.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.
"""Pass manager for optimization level 2, providing medium optimization.
Level 2 pass manager: medium optimization by noise adaptive qubit mapping and
gate cancellation using commutativity rules.
"""
from qiskit.transpiler.passmanager_config import PassManagerConfig
from qiskit.transpiler.timing_constraints import TimingConstraints
from qiskit.transpiler.passmanager import PassManager
from qiskit.transpiler.passmanager import StagedPassManager
from qiskit.transpiler.passes import SetLayout
from qiskit.transpiler.passes import VF2Layout
from qiskit.transpiler.passes import TrivialLayout
from qiskit.transpiler.passes import DenseLayout
from qiskit.transpiler.passes import NoiseAdaptiveLayout
from qiskit.transpiler.passes import SabreLayout
from qiskit.transpiler.passes import BasicSwap
from qiskit.transpiler.passes import LookaheadSwap
from qiskit.transpiler.passes import StochasticSwap
from qiskit.transpiler.passes import SabreSwap
from qiskit.transpiler.passes import FixedPoint
from qiskit.transpiler.passes import Depth
from qiskit.transpiler.passes import Size
from qiskit.transpiler.passes import Optimize1qGatesDecomposition
from qiskit.transpiler.passes import CommutativeCancellation
from qiskit.transpiler.passes import Error
from qiskit.transpiler.preset_passmanagers import common
from qiskit.transpiler.passes.layout.vf2_layout import VF2LayoutStopReason
from qiskit.transpiler import TranspilerError
from qiskit.utils.optionals import HAS_TOQM
[문서]def level_2_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassManager:
"""Level 2 pass manager: medium optimization by initial layout selection and
gate cancellation using commutativity rules.
This pass manager applies the user-given initial layout. If none is given, a search
for a perfect layout (i.e. one that satisfies all 2-qubit interactions) is conducted.
If no such layout is found, qubits are laid out on the most densely connected subset
which also exhibits the best gate fidelities.
The pass manager then transforms the circuit to match the coupling constraints.
It is then unrolled to the basis, and any flipped cx directions are fixed.
Finally, optimizations in the form of commutative gate cancellation and redundant
reset removal are performed.
Args:
pass_manager_config: configuration of the pass manager.
Returns:
a level 2 pass manager.
Raises:
TranspilerError: if the passmanager config is invalid.
"""
basis_gates = pass_manager_config.basis_gates
inst_map = pass_manager_config.inst_map
coupling_map = pass_manager_config.coupling_map
initial_layout = pass_manager_config.initial_layout
layout_method = pass_manager_config.layout_method or "dense"
routing_method = pass_manager_config.routing_method or "stochastic"
translation_method = pass_manager_config.translation_method or "translator"
scheduling_method = pass_manager_config.scheduling_method
instruction_durations = pass_manager_config.instruction_durations
seed_transpiler = pass_manager_config.seed_transpiler
backend_properties = pass_manager_config.backend_properties
approximation_degree = pass_manager_config.approximation_degree
unitary_synthesis_method = pass_manager_config.unitary_synthesis_method
timing_constraints = pass_manager_config.timing_constraints or TimingConstraints()
unitary_synthesis_plugin_config = pass_manager_config.unitary_synthesis_plugin_config
target = pass_manager_config.target
# Search for a perfect layout, or choose a dense layout, if no layout given
_given_layout = SetLayout(initial_layout)
def _choose_layout_condition(property_set):
# layout hasn't been set yet
return not property_set["layout"]
def _vf2_match_not_found(property_set):
# If a layout hasn't been set by the time we run vf2 layout we need to
# run layout
if property_set["layout"] is None:
return True
# if VF2 layout stopped for any reason other than solution found we need
# to run layout since VF2 didn't converge.
if (
property_set["VF2Layout_stop_reason"] is not None
and property_set["VF2Layout_stop_reason"] is not VF2LayoutStopReason.SOLUTION_FOUND
):
return True
return False
# Try using VF2 layout to find a perfect layout
_choose_layout_0 = (
[]
if pass_manager_config.layout_method
else VF2Layout(
coupling_map,
seed=seed_transpiler,
call_limit=int(5e6), # Set call limit to ~10 sec with retworkx 0.10.2
properties=backend_properties,
target=target,
)
)
if layout_method == "trivial":
_choose_layout_1 = TrivialLayout(coupling_map)
elif layout_method == "dense":
_choose_layout_1 = DenseLayout(coupling_map, backend_properties, target=target)
elif layout_method == "noise_adaptive":
_choose_layout_1 = NoiseAdaptiveLayout(backend_properties)
elif layout_method == "sabre":
_choose_layout_1 = SabreLayout(coupling_map, max_iterations=2, seed=seed_transpiler)
else:
raise TranspilerError("Invalid layout method %s." % layout_method)
toqm_pass = False
if routing_method == "basic":
routing_pass = BasicSwap(coupling_map)
elif routing_method == "stochastic":
routing_pass = StochasticSwap(coupling_map, trials=20, seed=seed_transpiler)
elif routing_method == "lookahead":
routing_pass = LookaheadSwap(coupling_map, search_depth=5, search_width=5)
elif routing_method == "sabre":
routing_pass = SabreSwap(coupling_map, heuristic="decay", seed=seed_transpiler)
elif routing_method == "toqm":
HAS_TOQM.require_now("TOQM-based routing")
from qiskit_toqm import ToqmSwap, ToqmStrategyO2, latencies_from_target
if initial_layout:
raise TranspilerError("Initial layouts are not supported with TOQM-based routing.")
toqm_pass = True
# Note: BarrierBeforeFinalMeasurements is skipped intentionally since ToqmSwap
# does not yet support barriers.
routing_pass = ToqmSwap(
coupling_map,
strategy=ToqmStrategyO2(
latencies_from_target(
coupling_map, instruction_durations, basis_gates, backend_properties, target
)
),
)
elif routing_method == "none":
routing_pass = Error(
msg="No routing method selected, but circuit is not routed to device. "
"CheckMap Error: {check_map_msg}",
action="raise",
)
else:
raise TranspilerError("Invalid routing method %s." % routing_method)
# Build optimization loop: 1q rotation merge and commutative cancellation iteratively until
# no more change in depth
_depth_check = [Depth(), FixedPoint("depth")]
_size_check = [Size(), FixedPoint("size")]
def _opt_control(property_set):
return (not property_set["depth_fixed_point"]) or (not property_set["size_fixed_point"])
_opt = [
Optimize1qGatesDecomposition(basis_gates),
CommutativeCancellation(basis_gates=basis_gates),
]
unroll_3q = None
# Build pass manager
if coupling_map or initial_layout:
unroll_3q = common.generate_unroll_3q(
target,
basis_gates,
approximation_degree,
unitary_synthesis_method,
unitary_synthesis_plugin_config,
)
layout = PassManager()
layout.append(_given_layout)
layout.append(_choose_layout_0, condition=_choose_layout_condition)
layout.append(_choose_layout_1, condition=_vf2_match_not_found)
layout += common.generate_embed_passmanager(coupling_map)
vf2_call_limit = None
if pass_manager_config.layout_method is None and pass_manager_config.initial_layout is None:
vf2_call_limit = int(5e6) # Set call limit to ~10 sec with retworkx 0.10.2
routing = common.generate_routing_passmanager(
routing_pass,
target,
coupling_map=coupling_map,
vf2_call_limit=vf2_call_limit,
backend_properties=backend_properties,
seed_transpiler=seed_transpiler,
use_barrier_before_measurement=not toqm_pass,
)
else:
layout = None
routing = None
translation = common.generate_translation_passmanager(
target,
basis_gates,
translation_method,
approximation_degree,
coupling_map,
backend_properties,
unitary_synthesis_method,
unitary_synthesis_plugin_config,
)
pre_routing = None
if toqm_pass:
pre_routing = translation
if (coupling_map and not coupling_map.is_symmetric) or (
target is not None and target.get_non_global_operation_names(strict_direction=True)
):
pre_optimization = common.generate_pre_op_passmanager(target, coupling_map, True)
else:
pre_optimization = common.generate_pre_op_passmanager(remove_reset_in_zero=True)
optimization = PassManager()
unroll = [pass_ for x in translation.passes() for pass_ in x["passes"]]
optimization.append(_depth_check + _size_check)
opt_loop = _opt + unroll + _depth_check + _size_check
optimization.append(opt_loop, do_while=_opt_control)
sched = common.generate_scheduling(
instruction_durations, scheduling_method, timing_constraints, inst_map
)
return StagedPassManager(
init=unroll_3q,
layout=layout,
pre_routing=pre_routing,
routing=routing,
translation=translation,
pre_optimization=pre_optimization,
optimization=optimization,
scheduling=sched,
)