Quantum Mutant Equivalence via Transpilation

2026-06-25

AI Summary

This study addresses the challenge of identifying equivalent mutants in quantum software mutation testing, which otherwise leads to resource waste and distorted mutation scores. To tackle this issue, the authors propose a lightweight equivalence detection method based on translational consistency of quantum circuits. The approach innovatively leverages comparison of generated OpenQASM code after circuit translation to identify semantically equivalent mutants without executing the circuits. Evaluated on 348,299 surviving mutants, the method accurately detected 29,536 equivalent mutants with 100% precision and an overall accuracy of 82%, significantly enhancing both the efficiency and reliability of quantum mutation testing.

Abstract

Mutation testing evaluates test suite quality by introducing artificial faults (mutants) and checking whether tests detect (kill) them. A central challenge is the equivalent mutant problem: some mutants are syntactically different from the original program but semantically identical to it and therefore cannot be killed by any test. If left unidentified, such mutants waste testing effort and distort mutation scores. In quantum software, mutation testing is increasingly used, but the equivalent mutant problem remains unsolved. A recent study generated more than 700,000 quantum circuit mutants and found that roughly half survived the available tests, making it unclear whether these survivors reflect weak tests or semantic equivalence. We propose Transpiler-Based Equivalence (TBE), a lightweight approach that identifies equivalent quantum mutants by transpiling original and mutated circuits under the same configuration and comparing their resulting OpenQASM code. We evaluate TBE on 348,299 surviving mutants, 92,011 of which are equivalent; TBE identifies 29,536 of them (32.1%) as equivalent while achieving 100% precision and 82% accuracy.

Problem

• equivalent mutant problem
• quantum mutation testing
• semantic equivalence
• quantum software testing

Innovation

• quantum mutation testing
• equivalent mutant problem
• transpilation
• OpenQASM
• test suite evaluation