configuration: BackendConfiguration,

properties: BackendProperties = None,

defaults: PulseDefaults = None,

custom_name_mapping: Optional[Dict[str, Any]] = None,

add_delay: bool = True,

filter_faulty: bool = True,

):

"""Decode transpiler target from backend data set.

This function generates :class:`.Target`` instance from intermediate

legacy objects such as :class:`.BackendProperties` and :class:`.PulseDefaults`.

These objects are usually components of the legacy :class:`.BackendV1` model.

Args:

configuration: Backend configuration as ``BackendConfiguration``

properties: Backend property dictionary or ``BackendProperties``

defaults: Backend pulse defaults dictionary or ``PulseDefaults``

custom_name_mapping: A name mapping must be supplied for the operation

not included in Qiskit Standard Gate name mapping, otherwise the operation

will be dropped in the resulting ``Target`` object.

add_delay: If True, adds delay to the instruction set.

filter_faulty: If True, this filters the non-operational qubits.

Returns:

A ``Target`` instance.

"""

# importing pacakges where they are needed, to avoid cyclic-import.

# pylint: disable=cyclic-import

from qiskit.transpiler.target import (

Target,

InstructionProperties,

)

from qiskit.circuit.controlflow import ForLoopOp, IfElseOp, SwitchCaseOp, WhileLoopOp

from qiskit.circuit.library.standard_gates import get_standard_gate_name_mapping

from qiskit.circuit.parameter import Parameter

from qiskit.circuit.gate import Gate

required = ["measure", "delay"]

# Load Qiskit object representation

qiskit_inst_mapping = get_standard_gate_name_mapping()

if custom_name_mapping:

qiskit_inst_mapping.update(custom_name_mapping)

qiskit_control_flow_mapping = {

"if_else": IfElseOp,

"while_loop": WhileLoopOp,

"for_loop": ForLoopOp,

"switch_case": SwitchCaseOp,

}

in_data = {"num_qubits": configuration.n_qubits}

# Parse global configuration properties

if hasattr(configuration, "dt"):

in_data["dt"] = configuration.dt

if hasattr(configuration, "timing_constraints"):

in_data.update(configuration.timing_constraints)

# Create instruction property placeholder from backend configuration

basis_gates = set(getattr(configuration, "basis_gates", []))

supported_instructions = set(getattr(configuration, "supported_instructions", []))

gate_configs = {gate.name: gate for gate in configuration.gates}

all_instructions = set.union(

basis_gates, set(required), supported_instructions.intersection(CONTROL_FLOW_OP_NAMES)

)

inst_name_map = {} # type: Dict[str, Instruction]

faulty_ops = set()

faulty_qubits = set()

unsupported_instructions = []

# Create name to Qiskit instruction object repr mapping

for name in all_instructions:

if name in qiskit_control_flow_mapping:

continue

if name in qiskit_inst_mapping:

inst_name_map[name] = qiskit_inst_mapping[name]

elif name in gate_configs:

# GateConfig model is a translator of QASM opcode.

# This doesn't have quantum definition, so Qiskit transpiler doesn't perform

# any optimization in quantum domain.

# Usually GateConfig counterpart should exist in Qiskit namespace so this is rarely called.

this_config = gate_configs[name]

params = list(map(Parameter, getattr(this_config, "parameters", [])))

coupling_map = getattr(this_config, "coupling_map", [])

inst_name_map[name] = Gate(

name=name,

num_qubits=len(coupling_map[0]) if coupling_map else 0,

params=params,

)

else:

warnings.warn(

f"No gate definition for {name} can be found and is being excluded "

"from the generated target. You can use `custom_name_mapping` to provide "

"a definition for this operation.",

RuntimeWarning,

)

unsupported_instructions.append(name)

for name in unsupported_instructions:

all_instructions.remove(name)

# Create inst properties placeholder

# Without any assignment, properties value is None,

# which defines a global instruction that can be applied to any qubit(s).

# The None value behaves differently from an empty dictionary.

# See API doc of Target.add_instruction for details.

prop_name_map = dict.fromkeys(all_instructions)

for name in all_instructions:

if name in gate_configs:

if coupling_map := getattr(gate_configs[name], "coupling_map", None):

# Respect operational qubits that gate configuration defines

# This ties instruction to particular qubits even without properties information.

# Note that each instruction is considered to be ideal unless

# its spec (e.g. error, duration) is bound by the properties object.

prop_name_map[name] = dict.fromkeys(map(tuple, coupling_map))

# Populate instruction properties

if properties:

def _get_value(prop_dict, prop_name):

if ndval := prop_dict.get(prop_name, None):

return ndval[0]

return None

# is_qubit_operational is a bit of expensive operation so precache the value

faulty_qubits = {

q for q in range(configuration.num_qubits) if not properties.is_qubit_operational(q)

}

qubit_properties = []

for qi in range(0, configuration.num_qubits):

# TODO faulty qubit handling might be needed since

# faulty qubit reporting qubit properties doesn't make sense.

try:

prop_dict = properties.qubit_property(qubit=qi)

except KeyError:

continue

qubit_properties.append(

QubitProperties(

t1=prop_dict.get("T1", (None, None))[0],

t2=prop_dict.get("T2", (None, None))[0],

frequency=prop_dict.get("frequency", (None, None))[0],

)

)

in_data["qubit_properties"] = qubit_properties

for name in all_instructions:

try:

for qubits, params in properties.gate_property(name).items():

if filter_faulty and (

set.intersection(faulty_qubits, qubits)

or not properties.is_gate_operational(name, qubits)

):

try:

# Qubits might be pre-defined by the gate config

# However properties objects says the qubits is non-operational

del prop_name_map[name][qubits]

except KeyError:

pass

faulty_ops.add((name, qubits))

continue

if prop_name_map[name] is None:

# This instruction is tied to particular qubits

# i.e. gate config is not provided, and instruction has been globally defined.

prop_name_map[name] = {}

prop_name_map[name][qubits] = InstructionProperties(

error=_get_value(params, "gate_error"),

duration=_get_value(params, "gate_length"),

)

if isinstance(prop_name_map[name], dict) and any(

v is None for v in prop_name_map[name].values()

):

# Properties provides gate properties only for subset of qubits

# Associated qubit set might be defined by the gate config here

logger.info(

"Gate properties of instruction %s are not provided for every qubits. "

"This gate is ideal for some qubits and the rest is with finite error. "

"Created backend target may confuse error-aware circuit optimization.",

name,

)

except BackendPropertyError:

# This gate doesn't report any property

continue

# Measure instruction property is stored in qubit property

prop_name_map["measure"] = {}

for qubit_idx in range(configuration.num_qubits):

if filter_faulty and (qubit_idx in faulty_qubits):

continue

qubit_prop = properties.qubit_property(qubit_idx)

prop_name_map["measure"][(qubit_idx,)] = InstructionProperties(

error=_get_value(qubit_prop, "readout_error"),

duration=_get_value(qubit_prop, "readout_length"),

)

for op in required:

# Map required ops to each operational qubit

if prop_name_map[op] is None:

prop_name_map[op] = {

(q,): None

for q in range(configuration.num_qubits)

if not filter_faulty or (q not in faulty_qubits)

}

if defaults:

inst_sched_map = defaults.instruction_schedule_map

for name in inst_sched_map.instructions:

for qubits in inst_sched_map.qubits_with_instruction(name):

if not isinstance(qubits, tuple):

qubits = (qubits,)

if (

name not in all_instructions

or name not in prop_name_map

or prop_name_map[name] is None

or qubits not in prop_name_map[name]

):

logger.info(

"Gate calibration for instruction %s on qubits %s is found "

"in the PulseDefaults payload. However, this entry is not defined in "

"the gate mapping of Target. This calibration is ignored.",

name,

qubits,

)

continue

if (name, qubits) in faulty_ops:

continue

entry = inst_sched_map._get_calibration_entry(name, qubits)

try:

prop_name_map[name][qubits].calibration = entry

except AttributeError:

logger.info(

"The PulseDefaults payload received contains an instruction %s on "

"qubits %s which is not present in the configuration or properties payload.",

name,

qubits,

)

# Add parsed properties to target

target = Target(**in_data)

for inst_name in all_instructions:

if inst_name == "delay" and not add_delay:

continue

if inst_name in qiskit_control_flow_mapping:

# Control flow operator doesn't have gate property.

target.add_instruction(

instruction=qiskit_control_flow_mapping[inst_name],

name=inst_name,

)

else:

target.add_instruction(

instruction=inst_name_map[inst_name],

properties=prop_name_map.get(inst_name, None),

name=inst_name,

)

properties: BackendProperties,

) -> List[QubitProperties]:

"""Uses BackendProperties to construct

and return a list of QubitProperties.

"""

qubit_props: List[QubitProperties] = []

for qubit, _ in enumerate(properties.qubits):

try:

t_1 = properties.t1(qubit)

except BackendPropertyError:

t_1 = None

try:

t_2 = properties.t2(qubit)

except BackendPropertyError:

t_2 = None

try:

frequency = properties.frequency(qubit)

except BackendPropertyError:

frequency = None

qubit_props.append(

QubitProperties( # type: ignore[no-untyped-call]

t1=t_1,

t2=t_2,

frequency=frequency,

)

)

"""A converter class that takes a :class:`~.BackendV1` instance and wraps it in a

:class:`~.BackendV2` interface.

This class implements the :class:`~.BackendV2` interface and is used to enable

common access patterns between :class:`~.BackendV1` and :class:`~.BackendV2`. This

class should only be used if you need a :class:`~.BackendV2` and still need

compatibility with :class:`~.BackendV1`.

When using custom calibrations (or other custom workflows) it is **not** recommended

to mutate the ``BackendV1`` object before applying this converter. For example, in order to

convert a ``BackendV1`` object with a customized ``defaults().instruction_schedule_map``,

which has a custom calibration for an operation, the operation name must be in

``configuration().basis_gates`` and ``name_mapping`` must be supplied for the operation.

Otherwise, the operation will be dropped in the resulting ``BackendV2`` object.

Instead it is typically better to add custom calibrations **after** applying this converter

instead of updating ``BackendV1.defaults()`` in advance. For example::

backend_v2 = BackendV2Converter(backend_v1)

backend_v2.target.add_instruction(

custom_gate, {(0, 1): InstructionProperties(calibration=custom_sched)}

)

"""

def __init__(

self,

backend: BackendV1,

name_mapping: Optional[Dict[str, Any]] = None,

add_delay: bool = True,

filter_faulty: bool = True,

):

"""Initialize a BackendV2 converter instance based on a BackendV1 instance.

Args:

backend: The input :class:`~.BackendV1` based backend to wrap in a

:class:`~.BackendV2` interface

name_mapping: An optional dictionary that maps custom gate/operation names in

``backend`` to an :class:`~.Operation` object representing that

gate/operation. By default most standard gates names are mapped to the

standard gate object from :mod:`qiskit.circuit.library` this only needs

to be specified if the input ``backend`` defines gates in names outside

that set.

add_delay: If set to true a :class:`~qiskit.circuit.Delay` operation

will be added to the target as a supported operation for all

qubits

filter_faulty: If the :class:`~.BackendProperties` object (if present) for

``backend`` has any qubits or gates flagged as non-operational filter

those from the output target.

"""

self._backend = backend

self._config = self._backend.configuration()

super().__init__(

provider=backend.provider,

name=backend.name(),

description=self._config.description,

online_date=getattr(self._config, "online_date", None),

backend_version=self._config.backend_version,

)

self._options = self._backend._options

self._properties = None

self._defaults = None

if hasattr(self._backend, "properties"):

self._properties = self._backend.properties()

if hasattr(self._backend, "defaults"):

self._defaults = self._backend.defaults()

self._target = None

self._name_mapping = name_mapping

self._add_delay = add_delay

self._filter_faulty = filter_faulty

@property

def target(self):

"""A :class:`qiskit.transpiler.Target` object for the backend.

:rtype: Target

"""

if self._target is None:

self._target = convert_to_target(

configuration=self._config,

properties=self._properties,

defaults=self._defaults,

custom_name_mapping=self._name_mapping,

add_delay=self._add_delay,

filter_faulty=self._filter_faulty,

)

return self._target

@property

def max_circuits(self):

return self._config.max_experiments

@classmethod

def _default_options(cls):

return Options()

@property

def dtm(self) -> float:

return self._config.dtm

@property

def meas_map(self) -> List[List[int]]:

return self._config.meas_map

def drive_channel(self, qubit: int):

return self._config.drive(qubit)

def measure_channel(self, qubit: int):

return self._config.measure(qubit)

def acquire_channel(self, qubit: int):

return self._config.acquire(qubit)

def control_channel(self, qubits: Iterable[int]):

return self._config.control(qubits)

def run(self, run_input, **options):