✨ Support directional compiler-target operation availability

[simon1hofmann]

🤖 AI text below 🤖

Description

Adds exact ordered operation applicability to CompilerTarget and uses it to support targets with one-way CX, ECR, and RZX gates.

• Separates operation applicability from optional calibration data, including unrestricted, explicitly empty, and explicit ordered site tuples.
• Preserves ordered applicability through QDMI, typed MQT attributes, Python bindings, serialization, mapping, synthesis, and target conformance.
• Wraps the immutable compiler target in a cached MappingTarget: topology traversal stays bidirectional, while mapping assigns the lower cost to the physical direction supported by the selected entangler.
• Precomputes directional two-qubit costs in O(E), giving average O(1) lookups in the mapping hot path instead of repeated support scans.
• Keeps the mapping pass synthesis-free; native synthesis performs any required direction repair and checks the exact emitted direction.
• Handles symmetric operations by reordering operands only when the reversed physical tuple is the supported one.

Fixes #2132

Verification

• Core release suites: Compiler 156/156, MQT IR 15/15, Mapping 96/96, and NativeSynthesis 37/37 passed.
• Python MLIR tests: 49/49 passed.
• Repository lint, C++ lint, strict documentation build, generated Python stubs, and git diff --check passed.
• Regression tests cover ambiguous one- and two-qubit sites and maximum valid target site IDs.
• Benchpress MQT integration: 53/53 passed, including focused one-way CX/ECR applicability and timeout round-trip tests.

AI assistance

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Checklist

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• I have added appropriate tests that cover the new/changed functionality.
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[simon1hofmann]

@MatthiasReumann Would you mind taking at first look here to see if this goes in the right direction?

[codecov]

Codecov Report

❌ Patch coverage is 98.29932% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...QCO/Transforms/NativeSynthesis/TargetSynthesis.cpp	97.0%	5 Missing ⚠️

📢 Thoughts on this report? Let us know!

[burgholzer]

I started an iteration on this already now. Will look at it in more detail tomorrow.

[burgholzer]

Still working through this one. Feels too large still, even after the simplifications.

[burgholzer]

@simon1hofmann Alright. I think I simplified this as far as I could. Would you mind checking the current implementation and whether it fulfills all goals you had in mind?

[simon1hofmann]

@simon1hofmann Alright. I think I simplified this as far as I could. Would you mind checking the current implementation and whether it fulfills all goals you had in mind?

Thanks a lot for the changes, the skipped benchpress test were successful based on this PR 🚀

[coderabbitai]

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[burgholzer]

I'll merge this now, given how it seems to resolve the underlying issues 🙌🏼