Impact of Comments on LLM Comprehension of Legacy Code

Impact of Comments on LLM Comprehension of Legacy Code Rock Sabetto, Emily Escamilla, Devesh Agarwal, Sujay Kandwal, Dr. Justin F. Brunelle, Dr. Scott Rosen, Dr. Nitin Naik, Dr. Samruddhi Thaker, Dr. Eric O. Scott, Jacob Zimmer, Amit Madan, Arun Sridharan, Doug Wendt, Michael Doyle, Christopher Glasz, Jasper Phillips, William Macke, Colin Diggs, Michael Bartholf, Zachary Robin, and Paul Ursino The MITRE Corporation McLean, V A rsabetto@mitre.org Abstract --Large language models (LLMs) have been increasingly integrated into software engineering and maintenance tasks due to their high performance with software engineering tasks and robust understanding of modern programming languages. However, the ability of LLMs to comprehend code written with legacy languages remains a research gap challenged by real-world legacy systems lacking or containing inaccurate documentation that may impact LLM comprehension. T o assess LLM comprehension of legacy languages, there is a need for objective LLM evaluation. In order to objectively measure LLM comprehension of legacy languages, we need an efficient, quantitative evaluation method. We leverage multiple-choice question answering (MCQA), an emerging LLM evaluation methodology, to evaluate LLM comprehension of legacy code and the impact of comment prevalence and inaccurate comments. In this work, we present preliminary findings on the impact of documentation on LLM comprehension of legacy code and outline strategic objectives for future work.