Qiskit / qiskit / 23708755076

87%

Build Type

push

github

Committed by web-flow

Commit Message

Simply Sabre release-valve calculation (#15897)

There is an edge case in release-valve handling where, if the shortest
path is a single swap (but the heuristics have been chosen such that it
is unselectable normally), it is possible for the release valve to cause
_two_ gates to be routed.  The previous handling of this path was
written in quite a complicated manner, likely to be able to use
`closest_node` by name from its discovery earlier in the release-valve
process.

Instead, it is easier to recognise that, given a single swap:

* the two qubits cannot be part of the same gate, or the gate would have
  been routable _without_ the swap;
* the `closest_node` must touch one of these qubits because of the
  the Dijkstra search;
* therefore we can simply add any routable gate that touches _either_
  qubit without risk of duplication or forgetting `closest_swap`.

Run Details

2 of 5 new or added lines in 1 file covered. (40.0%)

33 existing lines in 5 files now uncovered.

104008 of 118919 relevant lines covered (87.46%)

1000273.43 hits per line