mirror of https://github.com/Qiskit/qiskit.git
19 lines
1.0 KiB
YAML
19 lines
1.0 KiB
YAML
---
|
|
upgrade:
|
|
- |
|
|
The default routing pass and layout pass for transpiler optimization level 3 has
|
|
changed to use :class:`~qiskit.transpiler.passes.SabreSwap` and
|
|
:class:`~qiskit.transpiler.passes.SabreLayout` respectively. This
|
|
was done to improve the quality of the output result, as using the sabre
|
|
passes produces better results than using
|
|
:class:`~qiskit.transpiler.passes.StochasticSwap` and
|
|
:class:`~qiskit.transpiler.passes.DenseLayout`, which were used as the
|
|
defaults in prior releases. This change will improve the quality of the
|
|
results when running :func:`~qiskit.compiler.transpile` or
|
|
:func:`~qiskit.execute_function.execute` functions with the
|
|
``optimization_level`` kwarg set to ``3``. While this is generally an
|
|
improvement, if you need to retain the previous behavior for any reason
|
|
you can do this by explicitly setting the ``routing_method="stochastic"``
|
|
and ``layout_method="dense"`` when calling
|
|
:func:`~qiskit.compiler.transpile` with ``optimization_level=3``.
|