# -*- coding: utf-8 -*-
# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 2019.
#
# 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.
"""Circuit transpile function"""
import logging
from time import time
import warnings
from typing import List, Union, Dict, Callable, Any, Optional, Tuple
from qiskit.circuit.quantumcircuit import QuantumCircuit
from qiskit.providers import BaseBackend
from qiskit.providers.models import BackendProperties
from qiskit.transpiler import Layout, CouplingMap, PropertySet, PassManager
from qiskit.transpiler.basepasses import BasePass
from qiskit.dagcircuit import DAGCircuit
from qiskit.tools.parallel import parallel_map
from qiskit.transpiler.passmanager_config import PassManagerConfig
from qiskit.pulse import Schedule
from qiskit.circuit.quantumregister import Qubit
from qiskit import user_config
from qiskit.transpiler.exceptions import TranspilerError
from qiskit.converters import isinstanceint, isinstancelist
from qiskit.transpiler.passes.basis.ms_basis_decomposer import MSBasisDecomposer
from qiskit.transpiler.preset_passmanagers import (level_0_pass_manager,
level_1_pass_manager,
level_2_pass_manager,
level_3_pass_manager)
LOG = logging.getLogger(__name__)
[docs]def transpile(circuits: Union[QuantumCircuit, List[QuantumCircuit]],
backend: Optional[BaseBackend] = None,
basis_gates: Optional[List[str]] = None,
coupling_map: Optional[Union[CouplingMap, List[List[int]]]] = None,
backend_properties: Optional[BackendProperties] = None,
initial_layout: Optional[Union[Layout, Dict, List]] = None,
layout_method: Optional[str] = None,
routing_method: Optional[str] = None,
seed_transpiler: Optional[int] = None,
optimization_level: Optional[int] = None,
pass_manager: Optional[PassManager] = None,
callback: Optional[Callable[[BasePass, DAGCircuit, float,
PropertySet, int], Any]] = None,
output_name: Optional[Union[str, List[str]]] = None) -> Union[QuantumCircuit,
List[QuantumCircuit]]:
"""Transpile one or more circuits, according to some desired transpilation targets.
All arguments may be given as either a singleton or list. In case of a list,
the length must be equal to the number of circuits being transpiled.
Transpilation is done in parallel using multiprocessing.
Args:
circuits: Circuit(s) to transpile
backend: If set, transpiler options are automatically grabbed from
``backend.configuration()`` and ``backend.properties()``.
If any other option is explicitly set (e.g., ``coupling_map``), it
will override the backend's.
.. note::
The backend arg is purely for convenience. The resulting
circuit may be run on any backend as long as it is compatible.
basis_gates: List of basis gate names to unroll to
(e.g: ``['u1', 'u2', 'u3', 'cx']``). If ``None``, do not unroll.
coupling_map: Coupling map (perhaps custom) to target in mapping.
Multiple formats are supported:
#. ``CouplingMap`` instance
#. List, must be given as an adjacency matrix, where each entry
specifies all two-qubit interactions supported by backend,
e.g: ``[[0, 1], [0, 3], [1, 2], [1, 5], [2, 5], [4, 1], [5, 3]]``
backend_properties: properties returned by a backend, including information on gate
errors, readout errors, qubit coherence times, etc. Find a backend
that provides this information with: ``backend.properties()``
initial_layout: Initial position of virtual qubits on physical qubits.
If this layout makes the circuit compatible with the coupling_map
constraints, it will be used. The final layout is not guaranteed to be the same,
as the transpiler may permute qubits through swaps or other means.
Multiple formats are supported:
#. ``Layout`` instance
#. Dict
* virtual to physical::
{qr[0]: 0,
qr[1]: 3,
qr[2]: 5}
* physical to virtual::
{0: qr[0],
3: qr[1],
5: qr[2]}
#. List
* virtual to physical::
[0, 3, 5] # virtual qubits are ordered (in addition to named)
* physical to virtual::
[qr[0], None, None, qr[1], None, qr[2]]
layout_method: Name of layout selection pass ('trivial', 'dense', 'noise_adaptive')
Sometimes a perfect layout can be available in which case the layout_method
may not run.
routing_method: Name of routing pass ('basic', 'lookahead', 'stochastic')
seed_transpiler: Sets random seed for the stochastic parts of the transpiler
optimization_level: How much optimization to perform on the circuits.
Higher levels generate more optimized circuits,
at the expense of longer transpilation time.
* 0: no optimization
* 1: light optimization
* 2: heavy optimization
* 3: even heavier optimization
If ``None``, level 1 will be chosen as default.
pass_manager: The pass manager to use for a custom pipeline of transpiler passes.
If this arg is present, all other args will be ignored and the
pass manager will be used directly (Qiskit will not attempt to
auto-select a pass manager based on transpile options).
callback: A callback function that will be called after each
pass execution. The function will be called with 5 keyword
arguments,
| ``pass_``: the pass being run.
| ``dag``: the dag output of the pass.
| ``time``: the time to execute the pass.
| ``property_set``: the property set.
| ``count``: the index for the pass execution.
The exact arguments passed expose the internals of the pass manager,
and are subject to change as the pass manager internals change. If
you intend to reuse a callback function over multiple releases, be
sure to check that the arguments being passed are the same.
To use the callback feature, define a function that will
take in kwargs dict and access the variables. For example::
def callback_func(**kwargs):
pass_ = kwargs['pass_']
dag = kwargs['dag']
time = kwargs['time']
property_set = kwargs['property_set']
count = kwargs['count']
...
transpile(circ, callback=callback_func)
output_name: A list with strings to identify the output circuits. The length of
the list should be exactly the length of the ``circuits`` parameter.
Returns:
The transpiled circuit(s).
Raises:
TranspilerError: in case of bad inputs to transpiler (like conflicting parameters)
or errors in passes
"""
circuits = circuits if isinstance(circuits, list) else [circuits]
# transpiling schedules is not supported yet.
start_time = time()
if all(isinstance(c, Schedule) for c in circuits):
warnings.warn("Transpiling schedules is not supported yet.", UserWarning)
if len(circuits) == 1:
end_time = time()
_log_transpile_time(start_time, end_time)
return circuits[0]
end_time = time()
_log_transpile_time(start_time, end_time)
return circuits
if pass_manager is not None:
_check_conflicting_argument(optimization_level=optimization_level, basis_gates=basis_gates,
coupling_map=coupling_map, seed_transpiler=seed_transpiler,
backend_properties=backend_properties,
initial_layout=initial_layout, layout_method=layout_method,
routing_method=routing_method, backend=backend)
warnings.warn("The parameter pass_manager in transpile is being deprecated. "
"The preferred way to tranpile a circuit using a custom pass manager is"
" pass_manager.run(circuit)", DeprecationWarning, stacklevel=2)
return pass_manager.run(circuits, output_name=output_name, callback=callback)
if optimization_level is None:
# Take optimization level from the configuration or 1 as default.
config = user_config.get_config()
optimization_level = config.get('transpile_optimization_level', 1)
# Get transpile_args to configure the circuit transpilation job(s)
transpile_args = _parse_transpile_args(circuits, backend, basis_gates, coupling_map,
backend_properties, initial_layout,
layout_method, routing_method,
seed_transpiler, optimization_level,
callback, output_name)
_check_circuits_coupling_map(circuits, transpile_args, backend)
# Transpile circuits in parallel
circuits = parallel_map(_transpile_circuit, list(zip(circuits, transpile_args)))
if len(circuits) == 1:
end_time = time()
_log_transpile_time(start_time, end_time)
return circuits[0]
end_time = time()
_log_transpile_time(start_time, end_time)
return circuits
def _check_conflicting_argument(**kargs):
conflicting_args = [arg for arg, value in kargs.items() if value]
if conflicting_args:
raise TranspilerError("The parameters pass_manager conflicts with the following "
"parameter(s): {}.".format(', '.join(conflicting_args)))
def _check_circuits_coupling_map(circuits, transpile_args, backend):
# Check circuit width against number of qubits in coupling_map(s)
coupling_maps_list = list(config['pass_manager_config'].coupling_map for config in
transpile_args)
for circuit, parsed_coupling_map in zip(circuits, coupling_maps_list):
# If coupling_map is not None or num_qubits == 1
num_qubits = len(circuit.qubits)
max_qubits = None
if isinstance(parsed_coupling_map, CouplingMap):
max_qubits = parsed_coupling_map.size()
# If coupling_map is None, the limit might be in the backend (like in 1Q devices)
elif backend is not None and not backend.configuration().simulator:
max_qubits = backend.configuration().n_qubits
if max_qubits is not None and (num_qubits > max_qubits):
raise TranspilerError('Number of qubits ({}) '.format(num_qubits) +
'in {} '.format(circuit.name) +
'is greater than maximum ({}) '.format(max_qubits) +
'in the coupling_map')
def _log_transpile_time(start_time, end_time):
log_msg = "Total Transpile Time - %.5f (ms)" % ((end_time - start_time) * 1000)
LOG.info(log_msg)
def _transpile_circuit(circuit_config_tuple: Tuple[QuantumCircuit, Dict]) -> QuantumCircuit:
"""Select a PassManager and run a single circuit through it.
Args:
circuit_config_tuple (tuple):
circuit (QuantumCircuit): circuit to transpile
transpile_config (dict): configuration dictating how to transpile. The
dictionary has the following format:
{'optimization_level': int,
'pass_manager': PassManager,
'output_name': string,
'callback': callable,
'pass_manager_config': PassManagerConfig}
Returns:
The transpiled circuit
Raises:
TranspilerError: if transpile_config is not valid or transpilation incurs error
"""
circuit, transpile_config = circuit_config_tuple
pass_manager_config = transpile_config['pass_manager_config']
ms_basis_swap = None
if pass_manager_config.basis_gates is not None:
# Workaround for ion trap support: If basis gates includes
# Mølmer-Sørensen (rxx) and the circuit includes gates outside the basis,
# first unroll to u3, cx, then run MSBasisDecomposer to target basis.
basic_insts = ['measure', 'reset', 'barrier', 'snapshot']
device_insts = set(pass_manager_config.basis_gates).union(basic_insts)
if 'rxx' in pass_manager_config.basis_gates and \
not device_insts >= circuit.count_ops().keys():
ms_basis_swap = pass_manager_config.basis_gates
pass_manager_config.basis_gates = list(
set(['u3', 'cx']).union(pass_manager_config.basis_gates))
# we choose an appropriate one based on desired optimization level
level = transpile_config['optimization_level']
if level == 0:
pass_manager = level_0_pass_manager(pass_manager_config)
elif level == 1:
pass_manager = level_1_pass_manager(pass_manager_config)
elif level == 2:
pass_manager = level_2_pass_manager(pass_manager_config)
elif level == 3:
pass_manager = level_3_pass_manager(pass_manager_config)
else:
raise TranspilerError("optimization_level can range from 0 to 3.")
if ms_basis_swap is not None:
pass_manager.append(MSBasisDecomposer(ms_basis_swap))
return pass_manager.run(circuit, callback=transpile_config['callback'],
output_name=transpile_config['output_name'])
def _parse_transpile_args(circuits, backend,
basis_gates, coupling_map, backend_properties,
initial_layout, layout_method, routing_method,
seed_transpiler, optimization_level,
callback, output_name) -> List[Dict]:
"""Resolve the various types of args allowed to the transpile() function through
duck typing, overriding args, etc. Refer to the transpile() docstring for details on
what types of inputs are allowed.
Here the args are resolved by converting them to standard instances, and prioritizing
them in case a transpile option is passed through multiple args (explicitly setting an
arg has more priority than the arg set by backend).
Returns:
list[dicts]: a list of transpile parameters.
"""
if initial_layout is not None and layout_method is not None:
warnings.warn("initial_layout provided; layout_method is ignored.",
UserWarning)
# Each arg could be single or a list. If list, it must be the same size as
# number of circuits. If single, duplicate to create a list of that size.
num_circuits = len(circuits)
basis_gates = _parse_basis_gates(basis_gates, backend, circuits)
coupling_map = _parse_coupling_map(coupling_map, backend, num_circuits)
backend_properties = _parse_backend_properties(backend_properties, backend, num_circuits)
initial_layout = _parse_initial_layout(initial_layout, circuits)
layout_method = _parse_layout_method(layout_method, num_circuits)
routing_method = _parse_routing_method(routing_method, num_circuits)
seed_transpiler = _parse_seed_transpiler(seed_transpiler, num_circuits)
optimization_level = _parse_optimization_level(optimization_level, num_circuits)
output_name = _parse_output_name(output_name, circuits)
callback = _parse_callback(callback, num_circuits)
list_transpile_args = []
for args in zip(basis_gates, coupling_map, backend_properties,
initial_layout, layout_method, routing_method,
seed_transpiler, optimization_level,
output_name, callback):
transpile_args = {'pass_manager_config': PassManagerConfig(basis_gates=args[0],
coupling_map=args[1],
backend_properties=args[2],
initial_layout=args[3],
layout_method=args[4],
routing_method=args[5],
seed_transpiler=args[6]),
'optimization_level': args[7],
'output_name': args[8],
'callback': args[9]}
list_transpile_args.append(transpile_args)
return list_transpile_args
def _parse_basis_gates(basis_gates, backend, circuits):
# try getting basis_gates from user, else backend
if basis_gates is None:
if getattr(backend, 'configuration', None):
basis_gates = getattr(backend.configuration(), 'basis_gates', None)
# basis_gates could be None, or a list of basis, e.g. ['u3', 'cx']
if basis_gates is None or (isinstance(basis_gates, list) and
all(isinstance(i, str) for i in basis_gates)):
basis_gates = [basis_gates] * len(circuits)
return basis_gates
def _parse_coupling_map(coupling_map, backend, num_circuits):
# try getting coupling_map from user, else backend
if coupling_map is None:
if getattr(backend, 'configuration', None):
configuration = backend.configuration()
if hasattr(configuration, 'coupling_map') and configuration.coupling_map:
coupling_map = CouplingMap(configuration.coupling_map)
# coupling_map could be None, or a list of lists, e.g. [[0, 1], [2, 1]]
if coupling_map is None or isinstance(coupling_map, CouplingMap):
coupling_map = [coupling_map] * num_circuits
elif isinstance(coupling_map, list) and all(isinstance(i, list) and len(i) == 2
for i in coupling_map):
coupling_map = [coupling_map] * num_circuits
coupling_map = [CouplingMap(cm) if isinstance(cm, list) else cm for cm in coupling_map]
return coupling_map
def _parse_backend_properties(backend_properties, backend, num_circuits):
# try getting backend_properties from user, else backend
if backend_properties is None:
if getattr(backend, 'properties', None):
backend_properties = backend.properties()
if not isinstance(backend_properties, list):
backend_properties = [backend_properties] * num_circuits
return backend_properties
def _parse_initial_layout(initial_layout, circuits):
# initial_layout could be None, or a list of ints, e.g. [0, 5, 14]
# or a list of tuples/None e.g. [qr[0], None, qr[1]] or a dict e.g. {qr[0]: 0}
def _layout_from_raw(initial_layout, circuit):
if initial_layout is None or isinstance(initial_layout, Layout):
return initial_layout
elif isinstancelist(initial_layout):
if all(isinstanceint(elem) for elem in initial_layout):
initial_layout = Layout.from_intlist(initial_layout, *circuit.qregs)
elif all(elem is None or isinstance(elem, Qubit) for elem in initial_layout):
initial_layout = Layout.from_qubit_list(initial_layout)
elif isinstance(initial_layout, dict):
initial_layout = Layout(initial_layout)
else:
raise TranspilerError("The initial_layout parameter could not be parsed")
return initial_layout
# multiple layouts?
if isinstance(initial_layout, list) and \
any(isinstance(i, (list, dict)) for i in initial_layout):
initial_layout = [_layout_from_raw(lo, circ) if isinstance(lo, (list, dict)) else lo
for lo, circ in zip(initial_layout, circuits)]
else:
# even if one layout, but multiple circuits, the layout needs to be adapted for each
initial_layout = [_layout_from_raw(initial_layout, circ) for circ in circuits]
if not isinstance(initial_layout, list):
initial_layout = [initial_layout] * len(circuits)
return initial_layout
def _parse_layout_method(layout_method, num_circuits):
if not isinstance(layout_method, list):
layout_method = [layout_method] * num_circuits
return layout_method
def _parse_routing_method(routing_method, num_circuits):
if not isinstance(routing_method, list):
routing_method = [routing_method] * num_circuits
return routing_method
def _parse_seed_transpiler(seed_transpiler, num_circuits):
if not isinstance(seed_transpiler, list):
seed_transpiler = [seed_transpiler] * num_circuits
return seed_transpiler
def _parse_optimization_level(optimization_level, num_circuits):
if not isinstance(optimization_level, list):
optimization_level = [optimization_level] * num_circuits
return optimization_level
def _parse_pass_manager(pass_manager, num_circuits):
if not isinstance(pass_manager, list):
pass_manager = [pass_manager] * num_circuits
return pass_manager
def _parse_callback(callback, num_circuits):
if not isinstance(callback, list):
callback = [callback] * num_circuits
return callback
def _parse_output_name(output_name, circuits):
# naming and returning circuits
# output_name could be either a string or a list
if output_name is not None:
if isinstance(output_name, str):
# single circuit
if len(circuits) == 1:
return [output_name]
# multiple circuits
else:
raise TranspilerError("Expected a list object of length equal " +
"to that of the number of circuits " +
"being transpiled")
elif isinstance(output_name, list):
if len(circuits) == len(output_name) and \
all(isinstance(name, str) for name in output_name):
return output_name
else:
raise TranspilerError("The length of output_name list "
"must be equal to the number of "
"transpiled circuits and the output_name "
"list should be strings.")
else:
raise TranspilerError("The parameter output_name should be a string or a"
"list of strings: %s was used." % type(output_name))
else:
return [circuit.name for circuit in circuits]