CliffordT optimization #14433
Merged
CliffordT optimization #14433
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
|
One or more of the following people are relevant to this code:
|
Pull Request Test Coverage Report for Build 15293708241Warning: This coverage report may be inaccurate.This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.
Details
💛 - Coveralls |
| - | | ||
| Added a new :class:`.OptimizeCliffordT` transpiler optimization pass that | ||
| merges pairs of consecutive ``T``-gates into ``S``-gates and pairs of | ||
| consecutive ``Tdg``-gates into ``Sdg``-gates. |
There was a problem hiding this comment.
perhaps it's worth to explain that this is useful after SK? and provide some example?
rahaman-quantum
pushed a commit
to rahaman-quantum/qiskit
that referenced
this pull request
Jun 20, 2025
* CliffordT optimization * Adding OptimizeCliffordT to the Clifford+T pipeline * improving release notes based on review comments
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Outdated suggestions cannot be applied.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
This PR adds a Clifford+T optimization pass (see #14225 (review)). For now all it does is merging pairs of consecutive T-gates into S-gates, and pairs of consecutive Tdg-gates into Sdg-gates.
Despite its simplicity, it's already quite useful on circuits generated by the Solovay-Kitaev algorithm (which we call with
["t", "tdg", "h"]basis set) reducing the overall T-count by approximately 5%-10%.Longer-term the internals of this pass will be completely rewritten based on better algorithms available.
Details and comments
One can think of this as a placeholder for Clifford+T optimization algorithms that we are planning to implement.
I thought that
CommutativeCancellationcould merge consecutiveRzandT-rotations (exploiting commutativity), however it does not do that. And I could not find any other Qiskit pass that can do this for us.ToDo: add this to the optimization stage of the Clifford+T pipeline.