# 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 0, providing no explicit optimization.
Level 0 pass manager: no explicit optimization other than mapping to backend.
"""
from qiskit.transpiler.basepasses import BasePass
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 TrivialLayout
from qiskit.transpiler.passes import DenseLayout
from qiskit.transpiler.passes import NoiseAdaptiveLayout
from qiskit.transpiler.passes import SabreLayout
from qiskit.transpiler.preset_passmanagers import common
from qiskit.transpiler.preset_passmanagers.plugin import (
PassManagerStagePluginManager,
)
[ドキュメント]def level_0_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassManager:
"""Level 0 pass manager: no explicit optimization other than mapping to backend.
This pass manager applies the user-given initial layout. If none is given, a trivial
layout consisting of mapping the i-th virtual qubit to the i-th physical qubit is used.
Any unused physical qubit is allocated as ancilla space.
The pass manager then unrolls the circuit to the desired basis, and transforms the
circuit to match the coupling map.
Args:
pass_manager_config: configuration of the pass manager.
Returns:
a level 0 pass manager.
Raises:
TranspilerError: if the passmanager config is invalid.
"""
plugin_manager = PassManagerStagePluginManager()
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
init_method = pass_manager_config.init_method
layout_method = pass_manager_config.layout_method or "trivial"
routing_method = pass_manager_config.routing_method or "stochastic"
translation_method = pass_manager_config.translation_method or "translator"
optimization_method = pass_manager_config.optimization_method
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
timing_constraints = pass_manager_config.timing_constraints or TimingConstraints()
unitary_synthesis_method = pass_manager_config.unitary_synthesis_method
unitary_synthesis_plugin_config = pass_manager_config.unitary_synthesis_plugin_config
target = pass_manager_config.target
hls_config = pass_manager_config.hls_config
# Choose an initial layout if not set by user (default: trivial layout)
_given_layout = SetLayout(initial_layout)
def _choose_layout_condition(property_set):
return not property_set["layout"]
if target is None:
coupling_map_layout = coupling_map
else:
coupling_map_layout = target
if layout_method == "trivial":
_choose_layout: BasePass = TrivialLayout(coupling_map_layout)
elif layout_method == "dense":
_choose_layout = DenseLayout(coupling_map, backend_properties, target=target)
elif layout_method == "noise_adaptive":
if target is None:
_choose_layout = NoiseAdaptiveLayout(backend_properties)
else:
_choose_layout = NoiseAdaptiveLayout(target)
elif layout_method == "sabre":
skip_routing = pass_manager_config.routing_method is not None and routing_method != "sabre"
_choose_layout = SabreLayout(
coupling_map_layout,
max_iterations=1,
seed=seed_transpiler,
swap_trials=5,
layout_trials=5,
skip_routing=skip_routing,
)
# Choose routing pass
routing_pm = plugin_manager.get_passmanager_stage(
"routing", routing_method, pass_manager_config, optimization_level=0
)
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,
hls_config,
)
if layout_method not in {"trivial", "dense", "noise_adaptive", "sabre"}:
layout = plugin_manager.get_passmanager_stage(
"layout", layout_method, pass_manager_config, optimization_level=0
)
else:
def _swap_mapped(property_set):
return property_set["final_layout"] is None
layout = PassManager()
layout.append(_given_layout)
layout.append(_choose_layout, condition=_choose_layout_condition)
embed = common.generate_embed_passmanager(coupling_map_layout)
layout.append(
[pass_ for x in embed.passes() for pass_ in x["passes"]], condition=_swap_mapped
)
routing = routing_pm
else:
layout = None
routing = None
if translation_method not in {"translator", "synthesis", "unroller"}:
translation = plugin_manager.get_passmanager_stage(
"translation", translation_method, pass_manager_config, optimization_level=0
)
else:
translation = common.generate_translation_passmanager(
target,
basis_gates,
translation_method,
approximation_degree,
coupling_map,
backend_properties,
unitary_synthesis_method,
unitary_synthesis_plugin_config,
hls_config,
)
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_opt = common.generate_pre_op_passmanager(target, coupling_map)
pre_opt += translation
else:
pre_opt = None
if scheduling_method is None or scheduling_method in {"alap", "asap"}:
sched = common.generate_scheduling(
instruction_durations, scheduling_method, timing_constraints, inst_map, target=target
)
else:
sched = plugin_manager.get_passmanager_stage(
"scheduling", scheduling_method, pass_manager_config, optimization_level=0
)
init = common.generate_control_flow_options_check(
layout_method=layout_method,
routing_method=routing_method,
translation_method=translation_method,
optimization_method=optimization_method,
scheduling_method=scheduling_method,
basis_gates=basis_gates,
target=target,
)
if init_method is not None:
init += plugin_manager.get_passmanager_stage(
"init", init_method, pass_manager_config, optimization_level=0
)
elif unroll_3q is not None:
init += unroll_3q
optimization = None
if optimization_method is not None:
optimization = plugin_manager.get_passmanager_stage(
"optimization", optimization_method, pass_manager_config, optimization_level=0
)
return StagedPassManager(
init=init,
layout=layout,
routing=routing,
translation=translation,
pre_optimization=pre_opt,
optimization=optimization,
scheduling=sched,
)