Extend RetroQ with broader automated testing capabilities

Develop procedures for finding suitable initial states, generating test programs, automatically deriving structural expectations for quantum compiler passes, and extending RetroQ to additional quantum-computing frameworks, including Cirq and pytket.

Background

RetroQ is introduced as a black-box framework for testing quantum compiler passes through retromorphic testing and Hadamard-test-based verification. The evaluation demonstrates its ability to reproduce known defects and uncover previously undetected issues, but the reported experiments use small programs and a limited initialization strategy.

The authors explicitly identify four unresolved directions: finding suitable initial states, generating test programs, automatically deriving structural expectations for compiler passes, and supporting additional frameworks beyond PennyLane and Qiskit. These directions concern making the testing methodology more systematic, scalable, and broadly applicable.