# This code is part of Qiskit. # # (C) Copyright IBM 2021, 2023. # # 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. # pylint: disable=too-many-return-statements """ A target object represents the minimum set of information the transpiler needs from a backend """ from __future__ import annotations import itertools from typing import Optional, List, Any from collections.abc import Mapping import io import copy import logging import inspect import rustworkx as rx # import target class from the rust side from qiskit._accelerate.target import ( BaseTarget, BaseInstructionProperties, ) from qiskit.circuit.library.standard_gates import get_standard_gate_name_mapping from qiskit.circuit.duration import duration_in_dt from qiskit.transpiler.coupling import CouplingMap from qiskit.transpiler.exceptions import TranspilerError from qiskit.transpiler.instruction_durations import InstructionDurations from qiskit.transpiler.timing_constraints import TimingConstraints # import QubitProperties here to provide convenience alias for building a # full target from qiskit.providers.backend import QubitProperties # pylint: disable=unused-import logger = logging.getLogger(__name__) class InstructionProperties(BaseInstructionProperties): """A representation of the properties of a gate implementation. This class provides the optional properties that a backend can provide about an instruction. These represent the set that the transpiler can currently work with if present. However, if your backend provides additional properties for instructions you should subclass this to add additional custom attributes for those custom/additional properties by the backend. """ def __new__( # pylint: disable=keyword-arg-before-vararg cls, duration=None, # pylint: disable=keyword-arg-before-vararg error=None, # pylint: disable=keyword-arg-before-vararg *args, # pylint: disable=unused-argument **kwargs, # pylint: disable=unused-argument ): return super(InstructionProperties, cls).__new__( # pylint: disable=too-many-function-args cls, duration, error ) def __init__( self, duration: float | None = None, # pylint: disable=unused-argument error: float | None = None, # pylint: disable=unused-argument ): """Create a new ``InstructionProperties`` object Args: duration: The duration, in seconds, of the instruction on the specified set of qubits error: The average error rate for the instruction on the specified set of qubits. """ super().__init__() def __repr__(self): return f"InstructionProperties(duration={self.duration}, error={self.error})" class Target(BaseTarget): """ The intent of the ``Target`` object is to inform Qiskit's compiler about the constraints of a particular backend so the compiler can compile an input circuit to something that works and is optimized for a device. It currently contains a description of instructions on a backend and their properties as well as some timing information. However, this exact interface may evolve over time as the needs of the compiler change. These changes will be done in a backwards compatible and controlled manner when they are made (either through versioning, subclassing, or mixins) to add on to the set of information exposed by a target. As a basic example, let's assume backend has two qubits, supports :class:`~qiskit.circuit.library.UGate` on both qubits and :class:`~qiskit.circuit.library.CXGate` in both directions. To model this you would create the target like:: from qiskit.transpiler import Target, InstructionProperties from qiskit.circuit.library import UGate, CXGate from qiskit.circuit import Parameter gmap = Target() theta = Parameter('theta') phi = Parameter('phi') lam = Parameter('lambda') u_props = { (0,): InstructionProperties(duration=5.23e-8, error=0.00038115), (1,): InstructionProperties(duration=4.52e-8, error=0.00032115), } gmap.add_instruction(UGate(theta, phi, lam), u_props) cx_props = { (0,1): InstructionProperties(duration=5.23e-7, error=0.00098115), (1,0): InstructionProperties(duration=4.52e-7, error=0.00132115), } gmap.add_instruction(CXGate(), cx_props) Each instruction in the ``Target`` is indexed by a unique string name that uniquely identifies that instance of an :class:`~qiskit.circuit.Instruction` object in the Target. There is a 1:1 mapping between a name and an :class:`~qiskit.circuit.Instruction` instance in the target and each name must be unique. By default, the name is the :attr:`~qiskit.circuit.Instruction.name` attribute of the instruction, but can be set to anything. This lets a single target have multiple instances of the same instruction class with different parameters. For example, if a backend target has two instances of an :class:`~qiskit.circuit.library.RXGate` one is parameterized over any theta while the other is tuned up for a theta of pi/6 you can add these by doing something like:: import math from qiskit.transpiler import Target, InstructionProperties from qiskit.circuit.library import RXGate from qiskit.circuit import Parameter target = Target() theta = Parameter('theta') rx_props = { (0,): InstructionProperties(duration=5.23e-8, error=0.00038115), } target.add_instruction(RXGate(theta), rx_props) rx_30_props = { (0,): InstructionProperties(duration=1.74e-6, error=.00012) } target.add_instruction(RXGate(math.pi / 6), rx_30_props, name='rx_30') Then in the ``target`` object accessing by ``rx_30`` will get the fixed angle :class:`~qiskit.circuit.library.RXGate` while ``rx`` will get the parameterized :class:`~qiskit.circuit.library.RXGate`. You can optionally specify a bound on valid values on a gate in the target by using the ``angle_bounds`` keyword argument when calling the :meth:`.add_instruction` method. Bounds are set on operations not individual instructions, so when you call :meth:`.add_instruction` the bounds are applied for all qargs that it is defined on. The bounds are specified of a list of 2-tuples of floats where the first float is the lower bound and the second float is the upper bound. For example, if you specfied an angle bound:: [(0.0, 3.14), (-3.14, 3.14), (0.0, 1.0)] this indicates the angle bounds for a 3 parameter gate where the first parameter accepts angles between 0 and 3.14, the second between -3.14 and 3.14, and the third parameter between 0 and 1. All bounds are set inclusively as well. A bound can also be specified with ``None`` instead of a 2-tuple which indicates that parameter has no constraints. For example:: [(0.0, 3.14, None, None)] indicates an angle bound for a 3 parameter gate where only the first parameter is restricted to angles between 0.0 and 3.14 and the other parameters accept any value. You can check if any operations in the target have angle bounds set with, :meth:`.has_angle_bounds` and also if a specific name in the target has angle bounds set with :meth:`.gate_has_angle_bounds`. Whether a particular set of parameter values conforms to the angle bounds can be checked with :meth:`.supported_angle_bound`. In the preset pass managers the :class:`.WrapAngles` pass is used to enforce the angle bounds, for this to work you need to provide a function to the :class:`.WrapAngleRegistry` used by the pass. You can see more details on this in: :ref:`angle-bounds-on-gates`. This class can be queried via the mapping protocol, using the instruction's name as a key. You can modify any property for an instruction via the :meth:`.update_instruction_properties` method. Modification via the mapping protocol or mutating the attributes of a :class:`.InstructionProperties` object is **not** supported and doing so will invalidate the internal state of the object. .. note:: This class assumes that qubit indices start at 0 and are a contiguous set if you want a submapping the bits will need to be reindexed in a new :class:`Target` object. .. note:: This class only supports additions of gates, qargs, and properties. If you need to remove one of these the best option is to iterate over an existing object and create a new subset (or use one of the methods to do this). The object internally caches different views and these would potentially be invalidated by removals. Subclassing ----------- While it is technically possible to subclass :class:`Target`, beware that the majority of the built-in information is in Rust and is queried from Rust in built-in transpiler passes. Python-space overrides are not visible to Rust, and you should not rely on these to change the behavior of Qiskit's built-in transpiler passes. :class:`Target` is largely supposed to be a representation of a QPU that has specialized *constructors*, not specialized subclasses; the usual API for constructing a :class:`Target` should be a function that returns a base :class:`Target`, not a subclass with a custom initializer. You may use subclassing to add *addition* Python-space properties to your :class:`Target`, for example to then interpret in custom backend-specific transpiler stages; the :class:`Target` is passed to stage-plugin constructors. You should not subclass :class:`Target` to attempt to modify the behavior of Qiskit's built-in passes; the Python-space subclassing will not be seen by passes written in Rust. Further, as the core of :class:`Target` is written in Rust, it uses :meth:`~object.__new__` as its initializer, and you must ensure that the correct arguments are passed through to the underlying implementation. If you override the signature of the :meth:`~object.__init__` method, you must also include an override of :meth:`~object.__new__` with the same signature, which calls ``super().__new__()`` in a correct manner. """ __slots__ = ( "_gate_map", "_coupling_graph", "_instruction_durations", "_instruction_schedule_map", "_non_global_basis_strict", "_non_global_basis", ) def __new__( cls, description: str | None = None, num_qubits: int | None = 0, dt: float | None = None, granularity: int = 1, min_length: int = 1, pulse_alignment: int = 1, acquire_alignment: int = 1, qubit_properties: list | None = None, concurrent_measurements: list | None = None, **_subclass_kwargs, ): """ Create a new :class:`Target` object. Args: description (str): An optional string to describe the Target. num_qubits (int): An optional int to specify the number of qubits the backend target has. This is not a hard limit on the construction; any call to :meth:`add_instruction` will cause the set `num_qubits` to update to accommodate any concrete ``qargs`` in the given properties. This can be explicitly set to ``None`` to indicate a :class:`Target` representing a simulator or other abstract machine that imposes no limits on the number of qubits. In this case, all instructions added to the target should be global (with ``properties=None`` or ``properties={None: None}``). dt (float): The system time resolution of input signals in seconds granularity (int): An integer value representing minimum pulse gate resolution in units of ``dt``. A user-defined pulse gate should have duration of a multiple of this granularity value. min_length (int): An integer value representing minimum pulse gate length in units of ``dt``. A user-defined pulse gate should be longer than this length. pulse_alignment (int): An integer value representing a time resolution of gate instruction starting time. Gate instruction should start at time which is a multiple of the alignment value. acquire_alignment (int): An integer value representing a time resolution of measure instruction starting time. Measure instruction should start at time which is a multiple of the alignment value. qubit_properties (list): A list of :class:`~.QubitProperties` objects defining the characteristics of each qubit on the target device. If specified the length of this list must match the number of qubits in the target, where the index in the list matches the qubit number the properties are defined for. If some qubits don't have properties available you can set that entry to ``None`` concurrent_measurements(list): A list of sets of qubits that must be measured together. This must be provided as a nested list like ``[[0, 1], [2, 3, 4]]``. Raises: ValueError: If both ``num_qubits`` and ``qubit_properties`` are both defined and the value of ``num_qubits`` differs from the length of ``qubit_properties``. """ if description is not None: description = str(description) out = super(Target, cls).__new__( # pylint: disable=too-many-function-args cls, description, num_qubits, dt, granularity, min_length, pulse_alignment, acquire_alignment, qubit_properties, concurrent_measurements, ) # A nested mapping of gate name -> qargs -> properties out._gate_map = {} out._coupling_graph = None out._instruction_durations = None out._instruction_schedule_map = None out._non_global_basis = None out._non_global_basis_strict = None return out def get_non_global_operation_names(self, strict_direction=False): """Return the non-global operation names for the target The non-global operations are those in the target which don't apply on all qubits (for single qubit operations) or all multi-qubit qargs (for multi-qubit operations). Args: strict_direction (bool): If set to ``True`` the multi-qubit operations considered as non-global respect the strict direction (or order of qubits in the qargs is significant). For example, if ``cx`` is defined on ``(0, 1)`` and ``ecr`` is defined over ``(1, 0)`` by default neither would be considered non-global, but if ``strict_direction`` is set ``True`` both ``cx`` and ``ecr`` would be returned. Returns: List[str]: A list of operation names for operations that aren't global in this target """ if strict_direction: if self._non_global_basis_strict is None: self._non_global_basis_strict = super()._get_non_global_operation_names( strict_direction ) return self._non_global_basis_strict if self._non_global_basis is None: self._non_global_basis = super()._get_non_global_operation_names(strict_direction) return self._non_global_basis @property def dt(self): """Return dt.""" return self._dt @dt.setter def dt(self, dt): """Set dt and invalidate instruction duration cache""" self._dt = dt self._instruction_durations = None def add_instruction(self, instruction, properties=None, name=None, *, angle_bounds=None): """Add a new instruction to the :class:`~qiskit.transpiler.Target` As ``Target`` objects are strictly additive this is the primary method for modifying a ``Target``. Typically, you will use this to fully populate a ``Target`` before using it in :class:`~qiskit.providers.BackendV2`. For example:: from qiskit.circuit.library import CXGate from qiskit.transpiler import Target, InstructionProperties target = Target() cx_properties = { (0, 1): None, (1, 0): None, (0, 2): None, (2, 0): None, (0, 3): None, (2, 3): None, (3, 0): None, (3, 2): None } target.add_instruction(CXGate(), cx_properties) Will add a :class:`~qiskit.circuit.library.CXGate` to the target with no properties (duration, error, etc) with the coupling edge list: ``(0, 1), (1, 0), (0, 2), (2, 0), (0, 3), (2, 3), (3, 0), (3, 2)``. If there are properties available for the instruction you can replace the ``None`` value in the properties dictionary with an :class:`~qiskit.transpiler.InstructionProperties` object. This pattern is repeated for each :class:`~qiskit.circuit.Instruction` the target supports. Args: instruction (Union[qiskit.circuit.Instruction, Type[qiskit.circuit.Instruction]]): The operation object to add to the map. If it's parameterized any value of the parameter can be set. Optionally for variable width instructions (such as control flow operations such as :class:`~.ForLoop` or :class:`~MCXGate`) you can specify the class. If the class is specified than the ``name`` argument must be specified. When a class is used the gate is treated as global and not having any properties set. properties (dict): A dictionary of qarg entries to an :class:`~qiskit.transpiler.InstructionProperties` object for that instruction implementation on the backend. Properties are optional for any instruction implementation, if there are no :class:`~qiskit.transpiler.InstructionProperties` available for the backend the value can be None. If there are no constraints on the instruction (as in a noiseless/ideal simulation) this can be set to ``{None, None}`` which will indicate it runs on all qubits (or all available permutations of qubits for multi-qubit gates). The first ``None`` indicates it applies to all qubits and the second ``None`` indicates there are no :class:`~qiskit.transpiler.InstructionProperties` for the instruction. By default, if properties is not set it is equivalent to passing ``{None: None}``. name (str): An optional name to use for identifying the instruction. If not specified the :attr:`~qiskit.circuit.Instruction.name` attribute of ``gate`` will be used. All gates in the ``Target`` need unique names. Backends can differentiate between different parameterization of a single gate by providing a unique name for each (e.g. `"rx30"`, `"rx60", ``"rx90"`` similar to the example in the documentation for the :class:`~qiskit.transpiler.Target` class). angle_bounds (list): The bounds on the parameters for a given gate. This is specified by a list of tuples (low, high) which represent the low and high bound (inclusively) on what float values are allowed for the parameter in that position. If a parameter doesn't have an angle bound you can use ``None`` to represent that. For example if a 3 parameter gate only had a bound on the second parameter you would represent that with: ``[None, [0, 3.14], None]`` which means the first and third parameter allow any value but the second parameter only accepts values between 0 and 3.14. Raises: AttributeError: If gate is already in map TranspilerError: If an operation class is passed in for ``instruction`` and no name is specified or ``properties`` is set. """ is_class = inspect.isclass(instruction) if not is_class: instruction_name = name or instruction.name else: # Invalid to have class input without a name with characters set "" is not a valid name if not name: raise TranspilerError( "A name must be specified when defining a supported global operation by class" ) if properties is not None: raise TranspilerError( "An instruction added globally by class can't have properties set." ) instruction_name = name if properties is None or is_class: properties = {None: None} if instruction_name in self._gate_map: raise AttributeError(f"Instruction {instruction_name} is already in the target") super().add_instruction( instruction, instruction_name, properties, angle_bounds=angle_bounds ) self._gate_map[instruction_name] = properties self._coupling_graph = None self._instruction_durations = None self._instruction_schedule_map = None self._non_global_basis_strict = None self._non_global_basis = None def update_instruction_properties(self, instruction, qargs, properties): """Update the property object for an instruction qarg pair already in the Target. For ease of access, a user is able to obtain the mapping between an instruction's applicable qargs and its instruction properties via the mapping protocol (using ``__getitem__``), with the instruction's name as the key. This method is the only way to modify/update the properties of an instruction in the ``Target``. Usage of the mapping protocol for modifications is not supported. Args: instruction (str): The instruction name to update qargs (tuple): The qargs to update the properties of properties (InstructionProperties): The properties to set for this instruction Raises: KeyError: If ``instruction`` or ``qarg`` are not in the target """ super().update_instruction_properties(instruction, qargs, properties) self._gate_map[instruction][qargs] = properties self._instruction_durations = None self._instruction_schedule_map = None def qargs_for_operation_name(self, operation): """Get the qargs for a given operation name Args: operation (str): The operation name to get qargs for Returns: set: The set of qargs the gate instance applies to. """ if None in self._gate_map[operation]: return None return self._gate_map[operation].keys() def durations(self): """Get an InstructionDurations object from the target Returns: InstructionDurations: The instruction duration represented in the target """ if self._instruction_durations is not None: return self._instruction_durations out_durations = [] for instruction, props_map in self._gate_map.items(): for qarg, properties in props_map.items(): if properties is not None and properties.duration is not None: out_durations.append((instruction, list(qarg), properties.duration, "s")) self._instruction_durations = InstructionDurations(out_durations, dt=self.dt) return self._instruction_durations def timing_constraints(self): """Get an :class:`~qiskit.transpiler.TimingConstraints` object from the target Returns: TimingConstraints: The timing constraints represented in the ``Target`` """ return TimingConstraints( self.granularity, self.min_length, self.pulse_alignment, self.acquire_alignment ) @property def operation_names(self): """Get the operation names in the target.""" return self._gate_map.keys() @property def instructions(self): """Get the list of tuples (:class:`~qiskit.circuit.Instruction`, (qargs)) for the target For globally defined variable width operations the tuple will be of the form ``(class, None)`` where class is the actual operation class that is globally defined. """ return [ (self._gate_name_map[op], qarg) for op, qargs in self._gate_map.items() for qarg in qargs ] def instruction_properties(self, index): """Get the instruction properties for a specific instruction tuple This method is to be used in conjunction with the :attr:`~qiskit.transpiler.Target.instructions` attribute of a :class:`~qiskit.transpiler.Target` object. You can use this method to quickly get the instruction properties for an element of :attr:`~qiskit.transpiler.Target.instructions` by using the index in that list. However, if you're not working with :attr:`~qiskit.transpiler.Target.instructions` directly it is likely more efficient to access the target directly via the name and qubits to get the instruction properties. For example, if :attr:`~qiskit.transpiler.Target.instructions` returned:: [(XGate(), (0,)), (XGate(), (1,))] you could get the properties of the ``XGate`` on qubit 1 with:: props = target.instruction_properties(1) but just accessing it directly via the name would be more efficient:: props = target['x'][(1,)] (assuming the ``XGate``'s canonical name in the target is ``'x'``) This is especially true for larger targets as this will scale worse with the number of instruction tuples in a target. Args: index (int): The index of the instruction tuple from the :attr:`~qiskit.transpiler.Target.instructions` attribute. For, example if you want the properties from the third element in :attr:`~qiskit.transpiler.Target.instructions` you would set this to be ``2``. Returns: InstructionProperties: The instruction properties for the specified instruction tuple """ instruction_properties = [ inst_props for qargs in self._gate_map.values() for inst_props in qargs.values() ] return instruction_properties[index] def _build_coupling_graph(self): self._coupling_graph = rx.PyDiGraph(multigraph=False) if self.num_qubits is not None: self._coupling_graph.add_nodes_from([{} for _ in range(self.num_qubits)]) for gate, qarg_map in self._gate_map.items(): if qarg_map is None: if self._gate_name_map[gate].num_qubits == 2: self._coupling_graph = None # pylint: disable=attribute-defined-outside-init return continue for qarg, properties in qarg_map.items(): if qarg is None: if self.operation_from_name(gate).num_qubits == 2: self._coupling_graph = None return continue if len(qarg) == 1: self._coupling_graph[qarg[0]] = ( properties # pylint: disable=attribute-defined-outside-init ) elif len(qarg) == 2: try: edge_data = self._coupling_graph.get_edge_data(*qarg) edge_data[gate] = properties except rx.NoEdgeBetweenNodes: self._coupling_graph.add_edge(*qarg, {gate: properties}) qargs = self.qargs if self._coupling_graph.num_edges() == 0 and ( qargs is None or any(x is None for x in qargs) ): self._coupling_graph = None # pylint: disable=attribute-defined-outside-init def build_coupling_map(self, two_q_gate=None, filter_idle_qubits=False): """Get a :class:`~qiskit.transpiler.CouplingMap` from this target. If there is a mix of two qubit operations that have a connectivity constraint and those that are globally defined this will also return ``None`` because the globally connectivity means there is no constraint on the target. If you wish to see the constraints of the two qubit operations that have constraints you should use the ``two_q_gate`` argument to limit the output to the gates which have a constraint. Args: two_q_gate (str): An optional gate name for a two qubit gate in the ``Target`` to generate the coupling map for. If specified the output coupling map will only have edges between qubits where this gate is present. filter_idle_qubits (bool): If set to ``True`` the output :class:`~.CouplingMap` will remove any qubits that don't have any operations defined in the target. Note that using this argument will result in an output :class:`~.CouplingMap` object which has holes in its indices which might differ from the assumptions of the class. The typical use case of this argument is to be paired with :meth:`.CouplingMap.connected_components` which will handle the holes as expected. Returns: CouplingMap: The :class:`~qiskit.transpiler.CouplingMap` object for this target. If there are no connectivity constraints in the target this will return ``None``. Raises: ValueError: If a non-two qubit gate is passed in for ``two_q_gate``. IndexError: If an Instruction not in the ``Target`` is passed in for ``two_q_gate``. """ if self.qargs is None: return None if None not in self.qargs and any(len(x) > 2 for x in self.qargs): logger.warning( "This Target object contains multiqubit gates that " "operate on > 2 qubits. This will not be reflected in " "the output coupling map." ) if two_q_gate is not None: coupling_graph = rx.PyDiGraph(multigraph=False) coupling_graph.add_nodes_from([None] * self.num_qubits) for qargs, properties in self[two_q_gate].items(): if len(qargs) != 2: raise ValueError( f"Specified two_q_gate: {two_q_gate} is not a 2 qubit instruction" ) coupling_graph.add_edge(*qargs, {two_q_gate: properties}) cmap = CouplingMap() cmap.graph = coupling_graph return cmap if self._coupling_graph is None: self._build_coupling_graph() # if there is no connectivity constraints in the coupling graph treat it as not # existing and return if self._coupling_graph is not None: cmap = CouplingMap() if filter_idle_qubits: cmap.graph = self._filter_coupling_graph() else: cmap.graph = self._coupling_graph.copy() return cmap else: return None def _filter_coupling_graph(self): has_operations = set(itertools.chain.from_iterable(x for x in self.qargs if x is not None)) graph = self._coupling_graph.copy() to_remove = set(graph.node_indices()).difference(has_operations) if to_remove: graph.remove_nodes_from(list(to_remove)) return graph def __iter__(self): return iter(self._gate_map) def __getitem__(self, key): return self._gate_map[key] def get(self, key, default=None): """Gets an item from the Target. If not found return a provided default or `None`.""" try: return self[key] except KeyError: return default def __len__(self): return len(self._gate_map) def __contains__(self, item): return item in self._gate_map def keys(self): """Return the keys (operation_names) of the Target""" return self._gate_map.keys() def values(self): """Return the Property Map (qargs -> InstructionProperties) of every instruction in the Target""" return self._gate_map.values() def items(self): """Returns pairs of Gate names and its property map (str, dict[tuple, InstructionProperties])""" return self._gate_map.items() def __str__(self): output = io.StringIO() if self.description is not None: output.write(f"Target: {self.description}\n") else: output.write("Target\n") output.write(f"Number of qubits: {self.num_qubits}\n") output.write("Instructions:\n") for inst, qarg_props in self._gate_map.items(): output.write(f"\t{inst}\n") for qarg, props in qarg_props.items(): if qarg is None: continue if props is None: output.write(f"\t\t{qarg}\n") continue prop_str_pieces = [f"\t\t{qarg}:\n"] duration = getattr(props, "duration", None) if duration is not None: prop_str_pieces.append(f"\t\t\tDuration: {duration:g} sec.\n") error = getattr(props, "error", None) if error is not None: prop_str_pieces.append(f"\t\t\tError Rate: {error:g}\n") extra_props = getattr(props, "properties", None) if extra_props is not None: extra_props_pieces = [ f"\t\t\t\t{key}: {value}\n" for key, value in extra_props.items() ] extra_props_str = "".join(extra_props_pieces) prop_str_pieces.append(f"\t\t\tExtra properties:\n{extra_props_str}\n") output.write("".join(prop_str_pieces)) return output.getvalue() def __getstate__(self) -> dict: return { "_gate_map": self._gate_map, "coupling_graph": self._coupling_graph, "instruction_durations": self._instruction_durations, "instruction_schedule_map": self._instruction_schedule_map, "base": super().__getstate__(), } def __setstate__(self, state: tuple): self._gate_map = state["_gate_map"] self._coupling_graph = state["coupling_graph"] self._instruction_durations = state["instruction_durations"] self._instruction_schedule_map = state["instruction_schedule_map"] super().__setstate__(state["base"]) def seconds_to_dt(self, duration: float) -> int: """Convert a given duration in seconds to units of dt Args: duration: The duration in seconds, such as in an :class:`.InstructionProperties` field for an instruction in the target. Returns duration: The duration in units of dt """ return duration_in_dt(duration, self.dt) @classmethod def from_configuration( cls, basis_gates: list[str], num_qubits: int | None = None, coupling_map: CouplingMap | None = None, instruction_durations: InstructionDurations | None = None, concurrent_measurements: Optional[List[List[int]]] = None, dt: float | None = None, timing_constraints: TimingConstraints | None = None, custom_name_mapping: dict[str, Any] | None = None, ) -> Target: """Create a target object from the individual global configuration Prior to the creation of the :class:`~.Target` class, the constraints of a backend were represented by a collection of different objects which combined represent a subset of the information contained in the :class:`~.Target`. This function provides a simple interface to convert those separate objects to a :class:`~.Target`. This constructor will use the input from ``basis_gates``, ``num_qubits``, and ``coupling_map`` to build a base model of the backend and the ``instruction_durations``, ``backend_properties``, and ``inst_map`` inputs are then queried (in that order) based on that model to look up the properties of each instruction and qubit. If there is an inconsistency between the inputs any extra or conflicting information present in ``instruction_durations``, ``backend_properties``, or ``inst_map`` will be ignored. Args: basis_gates: The list of basis gate names for the backend. For the target to be created these names must either be in the output from :func:`~.get_standard_gate_name_mapping` or present in the specified ``custom_name_mapping`` argument. num_qubits: The number of qubits supported on the backend. coupling_map: The coupling map representing connectivity constraints on the backend. If specified all gates from ``basis_gates`` will be supported on all qubits (or pairs of qubits). instruction_durations: Optional instruction durations for instructions. If specified it will take priority for setting the ``duration`` field in the :class:`~InstructionProperties` objects for the instructions in the target. concurrent_measurements(list): A list of sets of qubits that must be measured together. This must be provided as a nested list like ``[[0, 1], [2, 3, 4]]``. dt: The system time resolution of input signals in seconds timing_constraints: Optional timing constraints to include in the :class:`~.Target` custom_name_mapping: An optional dictionary that maps custom gate/operation names in ``basis_gates`` 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 ``basis_gates`` defines gates in names outside that set. Returns: Target: the target built from the input configuration Raises: TranspilerError: If the input basis gates contain > 2 qubits and ``coupling_map`` is specified. KeyError: If no mapping is available for a specified ``basis_gate``. """ granularity = 1 min_length = 1 pulse_alignment = 1 acquire_alignment = 1 if timing_constraints is not None: granularity = timing_constraints.granularity min_length = timing_constraints.min_length pulse_alignment = timing_constraints.pulse_alignment acquire_alignment = timing_constraints.acquire_alignment qubit_properties = None target = cls( num_qubits=num_qubits, dt=dt, granularity=granularity, min_length=min_length, pulse_alignment=pulse_alignment, acquire_alignment=acquire_alignment, qubit_properties=qubit_properties, concurrent_measurements=concurrent_measurements, ) name_mapping = get_standard_gate_name_mapping() if custom_name_mapping is not None: name_mapping.update(custom_name_mapping) # While BackendProperties can also contain coupling information we # rely solely on CouplingMap to determine connectivity. This is because # in legacy transpiler usage # the coupling map is used to define connectivity constraints and # the properties is only used for error rate and duration population. # If coupling map is not specified we ignore the backend_properties if coupling_map is None: for gate in basis_gates: if gate not in name_mapping: raise KeyError( f"The specified basis gate: {gate} is not present in the standard gate " "names or a provided custom_name_mapping" ) target.add_instruction(name_mapping[gate], name=gate) else: one_qubit_gates = [] two_qubit_gates = [] global_ideal_variable_width_gates = [] # pylint: disable=invalid-name if num_qubits is None: num_qubits = len(coupling_map.graph) for gate in basis_gates: if gate not in name_mapping: raise KeyError( f"The specified basis gate: {gate} is not present in the standard gate " "names or a provided custom_name_mapping" ) gate_obj = name_mapping[gate] if gate_obj.num_qubits == 1: one_qubit_gates.append(gate) elif gate_obj.num_qubits == 2: two_qubit_gates.append(gate) elif inspect.isclass(gate_obj): global_ideal_variable_width_gates.append(gate) else: raise TranspilerError( f"The specified basis gate: {gate} has {gate_obj.num_qubits} " "qubits. This constructor method only supports fixed width operations " "with <= 2 qubits (because connectivity is defined on a CouplingMap)." ) for gate in one_qubit_gates: gate_properties: dict[tuple, InstructionProperties] = {} for qubit in range(num_qubits): error = None duration = None # Durations if specified manually should override model objects if instruction_durations is not None: try: duration = instruction_durations.get(gate, qubit, unit="s") except TranspilerError: duration = None if error is None and duration is None: gate_properties[(qubit,)] = None else: gate_properties[(qubit,)] = InstructionProperties( duration=duration, error=error ) target.add_instruction(name_mapping[gate], properties=gate_properties, name=gate) edges = list(coupling_map.get_edges()) for gate in two_qubit_gates: gate_properties = {} for edge in edges: error = None duration = None # Durations if specified manually should override model objects if instruction_durations is not None: try: duration = instruction_durations.get(gate, edge, unit="s") except TranspilerError: duration = None if error is None and duration is None: gate_properties[edge] = None else: gate_properties[edge] = InstructionProperties( duration=duration, error=error ) target.add_instruction(name_mapping[gate], properties=gate_properties, name=gate) for gate in global_ideal_variable_width_gates: target.add_instruction(name_mapping[gate], name=gate) return target Mapping.register(Target) class _FakeTarget(Target): """ Pseudo-target class for INTERNAL use in the transpilation pipeline. It's essentially an empty :class:`.Target` instance with a `coupling_map` argument that allows to store connectivity constraints without basis gates. This is intended to replace the use of loose constraints in the pipeline. """ def __new__( cls, coupling_map=None, # pylint: disable=unused-argument description=None, num_qubits=0, dt=None, granularity=1, min_length=1, pulse_alignment=1, acquire_alignment=1, qubit_properties=None, concurrent_measurements=None, ): return super().__new__( cls, description=description, num_qubits=num_qubits, dt=dt, granularity=granularity, min_length=min_length, pulse_alignment=pulse_alignment, acquire_alignment=acquire_alignment, qubit_properties=qubit_properties, concurrent_measurements=concurrent_measurements, ) def __init__( self, coupling_map=None, description=None, # pylint: disable=unused-argument num_qubits=0, # pylint: disable=unused-argument dt=None, # pylint: disable=unused-argument granularity=1, # pylint: disable=unused-argument min_length=1, # pylint: disable=unused-argument pulse_alignment=1, # pylint: disable=unused-argument acquire_alignment=1, # pylint: disable=unused-argument qubit_properties=None, # pylint: disable=unused-argument concurrent_measurements=None, # pylint: disable=unused-argument ): super().__init__() if coupling_map is None or isinstance(coupling_map, CouplingMap): self._coupling_map = coupling_map else: self._coupling_map = CouplingMap(coupling_map) def __len__(self): return len(self._gate_map) def build_coupling_map(self, *args, **kwargs): # pylint: disable=unused-argument return copy.deepcopy(self._coupling_map) def instruction_supported(self, *args, **kwargs): """Checks whether an instruction is supported by the Target based on instruction name and qargs. Note that if there are no basis gates in the Target, this method will always return ``True``. """ if len(self.operation_names) == 0: return True else: return super().instruction_supported(*args, **kwargs) @classmethod def from_configuration( cls, *args, num_qubits: int | None = None, coupling_map: CouplingMap | list | None = None, **kwargs, ) -> _FakeTarget: if num_qubits is None and coupling_map is not None: num_qubits = len(coupling_map.graph) return cls(num_qubits=num_qubits, coupling_map=coupling_map, *args, **kwargs)