Automated Benchmark Creation Boosts Hardware Verification

Author: Denis Avetisyan


A new reinforcement learning framework automatically generates complex hardware designs to rigorously test formal verification tools.

EvolveGen establishes a workflow for iterative refinement, systematically evolving generative models through a cycle of proposal, evaluation, and adaptation-a process designed to push the boundaries of what’s currently achievable.
EvolveGen establishes a workflow for iterative refinement, systematically evolving generative models through a cycle of proposal, evaluation, and adaptation-a process designed to push the boundaries of what’s currently achievable.

EvolveGen leverages high-level algorithmic descriptions to create diverse and challenging benchmarks for hardware model checking.

The increasing complexity of hardware designs is often contrasted by a limited availability of robust benchmarks for formal verification. To address this challenge, we present ‘EvolveGen: Algorithmic Level Hardware Model Checking Benchmark Generation through Reinforcement Learning’, a novel framework that leverages reinforcement learning and high-level synthesis to automatically generate challenging hardware benchmarks from algorithmic descriptions. EvolveGen creates functionally equivalent but structurally diverse designs, effectively exposing performance bottlenecks in state-of-the-art model checkers by optimizing for solver runtime as a reward signal. Will this approach enable the development of more scalable and effective formal verification techniques for increasingly complex hardware systems?


The Unfolding Complexity: A Verification Challenge

Contemporary hardware designs are experiencing an exponential surge in complexity, driven by demands for increased performance and functionality. This escalating intricacy presents a significant challenge to traditional functional verification techniques, which rely on exhaustively testing a system’s behavior. As the number of transistors on a single chip grows, so too does the state space that must be explored during verification – a space that quickly becomes intractable for conventional methods. Consequently, bugs and vulnerabilities can remain hidden within these complex designs, potentially leading to costly redesigns or, even worse, security breaches. The limitations of existing techniques are not merely a matter of computational resources; they represent a fundamental shift in the scale and nature of the verification problem, necessitating the development of novel approaches to ensure the reliability of modern hardware.

The escalating complexity of modern hardware introduces a significant challenge to functional verification, primarily due to the exponential growth of state spaces. Each additional component and interaction within a system multiplies the possible configurations and operational scenarios that must be tested. Traditional verification techniques, reliant on exhaustive simulation or limited random testing, quickly become impractical as the state space expands, leaving vast areas unexplored. This inability to thoroughly traverse all possible states creates opportunities for subtle bugs and security vulnerabilities to remain hidden, potentially manifesting as critical failures only after deployment. Consequently, ensuring the reliability of these systems demands innovative approaches capable of intelligently navigating and covering these immense state spaces, rather than attempting brute-force exploration.

The efficacy of functional verification hinges significantly on the quality of test cases; however, generating tests that thoroughly exercise a design’s capabilities presents a considerable challenge. Traditional methods often fall short in exploring the immense design space of modern hardware, leaving substantial coverage gaps where critical bugs can reside undetected. Innovative approaches are therefore crucial, moving beyond random stimulus to intelligently craft tests that target corner cases, complex interactions, and previously unexplored states. These methods leverage techniques like formal methods, machine learning, and constraint solving to automatically generate diverse and challenging test scenarios, ultimately increasing confidence in the design’s correctness and reducing the risk of post-silicon failures. The pursuit of better test generation isn’t merely about increasing coverage metrics; it’s about effectively probing the design’s behavior to reveal hidden vulnerabilities and ensure robust operation.

The system synthesizes computation graphs directly into hardware designs, streamlining the backend workflow.
The system synthesizes computation graphs directly into hardware designs, streamlining the backend workflow.

EvolveGen: Forcing Evolution in Verification

EvolveGen is an automated benchmark synthesis framework designed to enhance the rigor of hardware verification processes. Utilizing reinforcement learning algorithms, the system dynamically generates test cases intended to expose potential design flaws and vulnerabilities. Unlike traditional, static benchmark suites, EvolveGen adapts its test generation strategy based on feedback from the verification process, allowing it to efficiently explore the design space and create challenging scenarios. This automated approach reduces the reliance on manual test case creation, which is often time-consuming and may not adequately cover all critical design aspects. The framework aims to improve the effectiveness and efficiency of hardware verification by systematically generating diverse and challenging benchmarks.

EvolveGen employs a Computation Graph to model the hardware design undergoing verification as a network of interconnected operations. This graph represents the dataflow and control logic at a high level of abstraction, enabling the system to identify and prioritize critical code regions for testing. Nodes within the graph represent operations – such as addition, multiplication, or logical comparisons – while edges define the dependencies between them. By analyzing the graph’s structure, EvolveGen can pinpoint areas with complex control flow or significant data dependencies, focusing benchmark generation on these potentially problematic sections to maximize verification coverage and efficiently detect design flaws.

EvolveGen leverages a Multi-Armed Bandit (MAB) approach, enhanced by Reinforcement Learning (RL), to efficiently explore a space of algorithmic abstractions during benchmark generation. The MAB algorithm strategically balances exploration – trying new abstractions – with exploitation – focusing on those that have previously yielded effective test cases. The RL component optimizes this exploration-exploitation trade-off by learning which abstractions are most likely to generate diverse and high-quality tests, effectively guiding the search process. Benchmarks generated using this methodology have demonstrated a Quality Ratio (QR) at least ten times greater than those produced by state-of-the-art verification tools, indicating a significantly improved ability to expose design flaws.

Comparing the <span class="katex-eq" data-katex-display="false">Q_RQR</span> distribution reveals that baseline tools (AIGen, AIGFuzz, and FuzzBtor) focus on the 100 slowest generated benchmarks, while EvolveGen leverages its entire benchmark suite.
Comparing the Q_RQR distribution reveals that baseline tools (AIGen, AIGFuzz, and FuzzBtor) focus on the 100 slowest generated benchmarks, while EvolveGen leverages its entire benchmark suite.

Mapping the Machine: Computation Graphs in Detail

EvolveGen utilizes a ‘Computation Graph’ to model the data flow within a given hardware design, representing operations and their interrelationships. This graph explicitly identifies three core node types: ‘LoopNode’ which denote iterative processes; ‘BranchNode’ which represent conditional execution paths; and ‘OpNode’ which define individual operations performed on data. By mapping these nodes and their connections, EvolveGen can determine the dependencies between different parts of the design, enabling targeted test generation that focuses on critical data pathways and potential failure points arising from complex interactions between loops, branches, and operations.

EvolveGen’s focus on ‘DepNode’ – representing inter-iteration data dependencies – enables targeted test case generation for data-related bug detection. These ‘DepNode’s identify variables whose values in one iteration of a loop influence subsequent iterations, creating potential sources of errors if data is not handled correctly. By specifically crafting benchmarks that exercise these dependencies, the framework aims to reveal bugs stemming from incorrect data propagation, stale data access, or violations of assumed data invariants within the loop. This approach contrasts with random test generation, which may not adequately stress these critical data pathways and thus miss subtle, data-dependent bugs.

The reinforcement learning (RL) agent utilizes Thompson Sampling to optimize benchmark generation, focusing exploration on inputs likely to maximize coverage and effectively challenge verification tools. This approach prioritizes the creation of challenging test cases by balancing exploration and exploitation based on predicted reward values. The predictor model, used to estimate the reward signal for the RL agent, demonstrates a moderate degree of accuracy as measured by R-squared (R²) values of 0.60 for the rIC3 solver, 0.58 for the IC3Ref solver, and 0.46 for the Pono solver, indicating its ability to reasonably estimate the effectiveness of generated benchmarks.

Computation graphs utilize various node types, as exemplified by the illustrated code snippets demonstrating operations with a constant <span class="katex-eq" data-katex-display="false">c</span>.
Computation graphs utilize various node types, as exemplified by the illustrated code snippets demonstrating operations with a constant c.

The Crucible of Competition: HWMCC Results

EvolveGen-generated benchmarks have recently undergone rigorous testing within the prestigious Hardware Model Checking Competition (HWMCC), serving as crucial evaluation tools for state-of-the-art model checkers. Leading verification systems, including both ‘rIC3’ and ‘Pono’, were subjected to these automatically generated challenges, allowing for direct performance comparisons and identification of system limitations. This application demonstrates EvolveGen’s capability to create practical, competitive benchmarks that push the boundaries of formal verification technology and provide a standardized arena for assessing progress in the field. The results obtained from HWMCC using these benchmarks are actively informing development efforts, highlighting areas where existing tools require enhancement to handle increasingly complex hardware designs.

Evaluations using benchmarks created by EvolveGen consistently demonstrate limitations within current model checking tools. These generated tests aren’t simply random; they are specifically designed to expose vulnerabilities in the algorithms and implementations used for hardware verification. Notably, the process doesn’t merely identify failures, but provides insights that directly contribute to improvements in both the robustness – the ability to handle unexpected or malformed inputs – and the scalability – the capacity to efficiently verify increasingly complex designs – of these critical tools. By pinpointing performance bottlenecks and uncovering edge cases, the EvolveGen benchmarks act as a rigorous stress test, driving innovation and ensuring that hardware verification technology keeps pace with the growing demands of modern chip design.

EvolveGen significantly enhances the capabilities of existing hardware verification benchmark suites by dynamically generating challenging test cases. Leveraging tools such as AIGen, AIGFuzz, and FuzzBtor, the system creates complex scenarios that push the limits of established model checkers. This approach not only broadens the scope of verification – exposing weaknesses not revealed by standard benchmarks – but also rapidly identifies particularly difficult instances. These benchmarks frequently challenge baseline tools, often exceeding the 10-minute time limit for resolution and thereby pinpointing areas requiring optimization in verification algorithms and hardware design techniques.

The rIC3 method consistently outperforms Pono across the generated benchmark suite, demonstrating its superior performance.
The rIC3 method consistently outperforms Pono across the generated benchmark suite, demonstrating its superior performance.

Toward Autonomous Verification: The Future Unfolds

Ongoing development of EvolveGen prioritizes scalability to address the increasing intricacies of modern hardware designs. Researchers are actively working to broaden the system’s compatibility beyond current architectures, incorporating support for heterogeneous computing platforms and advanced memory hierarchies. This expansion necessitates the integration of diverse verification methodologies, including formal methods and advanced simulation techniques, to ensure comprehensive testing at all levels of abstraction. By enhancing EvolveGen’s ability to handle these complexities, the system aims to remain a viable solution as hardware continues to evolve, ultimately reducing the reliance on manual intervention in the verification process and accelerating time-to-market for innovative technologies.

A significant advancement lies in the potential synergy between EvolveGen and High-Level Synthesis (HLS) tools. Currently, hardware design and verification are largely sequential processes; engineers first create a design and then develop a verification environment to test it. Integrating EvolveGen with HLS could revolutionize this workflow by enabling automated co-design. HLS translates abstract algorithmic descriptions into hardware implementations, and EvolveGen could concurrently generate verification environments tailored to the specific, synthesized hardware. This co-design approach promises not only to accelerate the verification process but also to enhance its effectiveness, as the verification environment is intrinsically linked to the actual implementation, ensuring comprehensive test coverage and reducing the likelihood of post-silicon bugs. The resulting automated flow would dramatically lower the barriers to entry for designing and verifying increasingly complex hardware systems.

The escalating complexity of modern hardware demands a paradigm shift in verification methodologies, and this research represents a crucial step toward realizing truly autonomous systems. These systems won’t merely identify errors, but will dynamically refine their verification strategies based on evolving hardware designs – essentially learning to verify hardware itself. This adaptive capability is achieved through the continuous feedback loop inherent in the evolutionary algorithms employed, allowing the verification environment to optimize for efficiency and coverage as designs become increasingly intricate. Consequently, such systems promise to alleviate the growing bottleneck in hardware development, reducing time-to-market and enhancing the reliability of future technologies by proactively addressing verification challenges before they manifest as costly errors.

The pursuit of robust hardware verification, as demonstrated by EvolveGen, inherently involves a deliberate dismantling of assumed system stability. This framework doesn’t merely test designs; it actively seeks their breaking points through iteratively generated benchmarks. As Marvin Minsky observed, “You can’t always get what you want, but sometimes you find what you need.” EvolveGen exemplifies this; it doesn’t aim for perfect designs, but for the discovery of design weaknesses – the ‘bugs’ confessing the system’s sins. The reinforcement learning agent, by pushing the boundaries of complexity within the computation graph, effectively reverse-engineers the limits of the hardware, exposing vulnerabilities that traditional benchmarks might overlook. This process isn’t about fixing errors, but about understanding-and thus, ultimately strengthening-the underlying architecture.

Cracking the Code

The automation of benchmark generation, as demonstrated by EvolveGen, isn’t simply about creating more test cases; it’s a tacit admission that the current suite of verification challenges is, at best, a limited sampling of the possible. Reality, after all, is open source-one just hasn’t read the code yet. This work suggests that the true difficulty in formal verification isn’t necessarily the size of the design space, but its unfamiliarity. The framework offers a means to systematically explore previously unconsidered algorithmic implementations, forcing formal tools to move beyond pattern matching and towards genuine understanding.

However, the reliance on reinforcement learning introduces its own set of constraints. The agent, while effective at generating challenging benchmarks, remains bound by the reward function. What constitutes “challenging” is, by definition, subjective. Future iterations might explore methods for the agent to independently define complexity, or to leverage adversarial techniques to actively seek out weaknesses in verification tools – truly reverse-engineering the limits of existing solvers.

Ultimately, the most intriguing question isn’t whether one can find bugs, but whether one can predict where they will emerge. A framework capable of generating benchmarks with known vulnerabilities – or, even better, those that statistically mirror the distribution of errors found in real-world hardware – would represent a significant leap towards proactive, rather than reactive, verification. The current work lays the foundation; the hard part, naturally, is decoding the underlying operating system.


Original article: https://arxiv.org/pdf/2602.22609.pdf

Contact the author: https://www.linkedin.com/in/avetisyan/

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2026-02-28 18:24