Does Sabre transpiler support Fidelity information?

[geexie]

@alecandido, I have fidelity and lifetime information for my QPU, how can I pass this information to SABRE for routing? In original paper SABRE takes 3 inputs: Qubit Lifetime, Operation Fidelity and Qubits Coupling. Now I use only the last one. Does the former are also supported?

[alecandido]

What is called Sabre in Qibo I believe it is only a partial reimplementation of the original SABRE algorithm. Before @csookim's work, it was even performing worse.

The available parameters are described in the class documentation,

qibo/src/qibo/transpiler/router.py

Lines 579 to 598 in 14b62c4

	class Sabre(Router):
	"""Routing algorithm proposed in Ref [1].
	Args:
	connectivity (:class:`networkx.Graph`): Hardware chip connectivity.
	lookahead (int, optional): Lookahead factor, how many dag layers will be considered
	in computing the cost. Defaults to :math:`2`.
	decay_lookahead (float, optional): Value in interval :math:`[0, 1]`.
	How the weight of the distance in the dag layers decays in computing the cost.
	Defaults to :math:`0.6`.
	delta (float, optional): Defines the number of SWAPs vs depth trade-off by deciding
	how the algorithm tends to select non-overlapping SWAPs.
	Defaults to math:`10^{-3}`.
	seed (int, optional): Seed for the candidate random choice as tiebraker.
	Defaults to ``None``.
	swap_threshold (float, optional): Limits the number of added SWAPs in every routing iteration.
	This threshold is multiplied by the length of the longest path in the circuit connectivity.
	If the number of added SWAPs exceeds the threshold before a gate is routed,
	shortestpath routing is applied.
	Defaults to :math:`1.5`.

which for some reason is not rendered in the API docs 🤷 (we should check this, @renatomello @BrunoLiegiBastonLiegi)

However, there is no way to consume the information you have in the current Qibo transpiler. And that's one of the reason why contributions are appreciated :)

[renatomello]

which for some reason is not rendered in the API docs 🤷 (we should check this, @renatomello @BrunoLiegiBastonLiegi)

It seems like the entire transpiler is missing from the API Reference and is only being mentioned in the Advanced Examples.

[alecandido]

It seems like the entire transpiler is missing from the API Reference and is only being mentioned in the Advanced Examples.

Yes, and I fear that the cause is that the API scraping has never been automated, like in the other packages.
https://github.com/qiboteam/qibo/blob/master/doc/source/api-reference/qibo.rst?plain=1

In Qibolab we have this hook in docs generation, which first scrapes the source code to automatically generate the API docs.

However, Qibo contains manually written text within the docs. It has been there historically, so I never removed it, and the auto-generation would overwrite it (not committing it in the repo, but effectively ignoring that content).
So, we either keep maintaining it manually, or we should step into the auto-generation, moving the content from the qibo.rst file, to the source files' docstrings.

I guess we also need a separate issue for this.

[geexie]

@alecandido, thanks for your replay! I see. I would appreciate if we can setup a small zoom call to discuss transpiler internals🙏🏻 Currently I'm very interested in transpilation topic.