✨ Add native gate profile parsing and Euler R-basis synthesis

[simon1hofmann]

Description

Adds NativeProfileSpec for parsing comma-separated native gate menus (e.g. "u,cx", "x,sx,rz,cx", "r,cz") and driving two-qubit Weyl synthesis from the resolved menu. Extends Euler decomposition with an R basis (R(θ,0) · R(θ,π/2) · R(θ,0)) for IQM-style native sets.

Native profile

• parseNativeSpec validates single-qubit strategy + cx/cz entangler (cx preferred when both present)
• synthesizeUnitary2QWeyl emits Weyl decompositions via cached CX/CZ basis decomposers

Euler R basis

• EulerBasis::R synthesis and parseEulerBasis("r")
• fuse-single-qubit-unitary-runs recognizes ROp as an R-basis gate

AI Assistance

Used Composer 2.5 via Cursor for parts of this change. I reviewed the full
diff and take responsibility for everything in this PR.

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• I have added entries to the changelog for any noteworthy additions, changes, fixes, or removals.
• I have added migration instructions to the upgrade guide (if needed).
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

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[codecov]

Codecov Report

❌ Patch coverage is 96.29630% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ect/QCO/Transforms/Decomposition/NativeProfile.cpp	96.4%	5 Missing ⚠️
...lib/Dialect/QCO/Transforms/Decomposition/Euler.cpp	94.4%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[simon1hofmann]

@coderabbitai full review

[coderabbitai]

✅ Action performed

Full review finished.

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 48ba83ff-3ce2-4a49-ab57-6beaa6ba5281

📥 Commits

Reviewing files that changed from the base of the PR and between 3bf1324 and c751462.

📒 Files selected for processing (2)

• mlir/lib/Dialect/QCO/Transforms/Decomposition/NativeProfile.cpp
• mlir/unittests/Dialect/QCO/Transforms/Decomposition/test_weyl_decomposition.cpp

👮 Files not reviewed due to content moderation or server errors (2)

• mlir/lib/Dialect/QCO/Transforms/Decomposition/NativeProfile.cpp
• mlir/unittests/Dialect/QCO/Transforms/Decomposition/test_weyl_decomposition.cpp

---

📝 Walkthrough

Summary by CodeRabbit

• New Features

  • Added support for an additional Euler basis option, expanding the available synthesis choices.
  • Introduced native gate profile handling so supported gate sets can be parsed, checked, and used during synthesis.
  • Added two-qubit synthesis support that can adapt to the selected native gate menu.

• Bug Fixes

  • Improved single-qubit gate recognition and error messaging for the new basis option.
  • Updated global phase handling to avoid unnecessary phase operations when not needed.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main changes: native gate profile parsing and the new Euler R-basis synthesis.
Description check	✅ Passed	The description follows the template with a clear summary and checklist, though it omits an issue reference and explicit dependencies.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch native-profile-euler

---

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@mlir/lib/Dialect/QCO/Transforms/Decomposition/NativeProfile.cpp`:
- Around line 196-211: The decomposition path in NativeProfile::decomposeTarget
should not call spec.eulerBasis() unless a single-qubit strategy has been
resolved. After the entangler/native gate checks in NativeProfile.cpp, add a
guard for the missing Euler basis and return failure() when NativeProfileSpec
has no resolved basis. Use the existing flow around selectEntangler,
cachedBasisDecomposer(...).decomposeTarget(...), and the later basis-dependent
code so the optional is validated before dereferencing.

In
`@mlir/unittests/Dialect/QCO/Transforms/Decomposition/test_weyl_decomposition.cpp`:
- Around line 465-478: The reconstruction helper currently skips func::ReturnOp
and silently ignores unknown non-unitary ops, which lets invalid qubit returns
or stale inputs pass. Update the loop in the reconstruction logic around the
unitary scan to validate the returned qubits explicitly against the expected
reconstructed qubits, and make any non-unitary/non-GPhase op that is not handled
cause reconstruction to fail rather than continuing. Use the existing helper in
test_weyl_decomposition.cpp that iterates over funcOp.getBody().front() so the
check is enforced wherever the reconstruction result is verified.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 26e05bb4-59f5-4f6c-9f15-f1ee0e8fc6fa

📥 Commits

Reviewing files that changed from the base of the PR and between 58e44bb and 3bf1324.

📒 Files selected for processing (8)

• mlir/include/mlir/Dialect/QCO/Transforms/Decomposition/Euler.h
• mlir/include/mlir/Dialect/QCO/Transforms/Decomposition/NativeProfile.h
• mlir/include/mlir/Dialect/QCO/Transforms/Passes.td
• mlir/lib/Dialect/QCO/Transforms/Decomposition/Euler.cpp
• mlir/lib/Dialect/QCO/Transforms/Decomposition/NativeProfile.cpp
• mlir/lib/Dialect/QCO/Transforms/NativeSynthesis/FuseSingleQubitUnitaryRuns.cpp
• mlir/unittests/Dialect/QCO/Transforms/Decomposition/test_euler_decomposition.cpp
• mlir/unittests/Dialect/QCO/Transforms/Decomposition/test_weyl_decomposition.cpp

[simon1hofmann]

@coderabbitai review

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