Fix ElidePermutations pass in the presence of PermutationGates (backport #14603)
#14623
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Thank you for opening a new pull request. Before your PR can be merged it will first need to pass continuous integration tests and be reviewed. Sometimes the review process can be slow, so please be patient. While you're waiting, please feel free to review other open PRs. While only a subset of people are authorized to approve pull requests for merging, everyone is encouraged to review open pull requests. Doing reviews helps reduce the burden on the core team and helps make the project's code better for everyone. One or more of the following people are relevant to this code:
|
Pull Request Test Coverage Report for Build 15686377268Details
💛 - Coveralls |
mtreinish
approved these changes
Jun 16, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
Fixes #14602.
Details and comments
The
ElidePermutationstranspiler pass removes swap gates and permutation gates from the circuit, tracking the current permutation of the qubits using the internal variablemapping. Previously, this mapping was not updated correctly in the presence of permutation gates, leading to incorrect output circuits and updates to the pass manager's property set (namely, to"virtual_permutation_layout").The correct update rule should be$$M [ Q [i] ] \leftarrow M [Q [ P[i] ] ]$$ for $i=1,\dots,k$ , where $M$ is the current mapping within the $Q$ is the set of qubits the permutation gate is defined on, and $P$ is the "permutation pattern" of the permutation gate (stating which qubits get mapped to positions $0$ , $1$ , etc. when the permutation gate is applied).
ElidePermutationspass,This is an automatic backport of pull request #14603 done by Mergify.