VAST

• Overview — What VAST is and why it exists, explained without jargon
• Introduction — What the VAST program is and why it matters for compiler trust
• How it works — The VAST pipeline: generation, three-path execution, and comparison
• Why it matters — What changes when a compiler project runs its own verification program
• CLI reference — Running the VAST program: flags, profiles, modes, and usage examples
• Differential testing — How VAST uses multiple independent execution paths to find compiler bugs through disagreement
• Metamorphic testing — How VAST verifies compiler correctness by applying semantics-preserving transforms and checking that results stay the same
• Mutation testing — How VAST uses mutation expansion to validate its own detection infrastructure
• Reduction — How VAST automatically shrinks failing programs to minimal reproducers
• Value pools — How VAST uses value pools to generate programs with richer data flow and deeper semantic coverage
• CI integration — Running VAST in CI: fast, deep, and continuous modes, dashboards, coverage, and seed rotation
• VAST vs mutate — How vary vast and vary mutate differ in purpose, technique, and what they find
• Comparison with other systems — How VAST compares to Csmith, Alive2, CompCert, QuickCheck, LangFuzz, and other compiler testing tools
• Coverage and confidence — Semantic coverage, feature interactions, confidence scoring, and stress testing
• Testing playbook — When to run what, how to interpret results, and how to act on failures
• Future phases — What we are considering for future VAST work