Code-generating Large Language Models (LLMs) have become essential tools in modern software development, enhancing productivity and accelerating development. This paper aims to investigate the fine-tuning of code-generating LLMs using Reinforcement Learning and Direct Preference Optimization, further improving their performance. To achieve this, we enhance the training data for the reward model with the help of symbolic execution techniques, ensuring more comprehensive and objective data. With symbolic execution, we create a custom dataset that better captures the nuances in code evaluation. Our reward models, fine-tuned on this dataset, demonstrate significant improvements over the baseline, CodeRL, in estimating the quality of generated code. Our code-generating LLMs, trained with the help of reward model feedback, achieve similar results compared to the CodeRL benchmark.
View on arXiv@article{sakharova2025_2504.15210,
title={ Integrating Symbolic Execution into the Fine-Tuning of Code-Generating LLMs },
author={ Marina Sakharova and Abhinav Anand and Mira Mezini },
journal={arXiv preprint arXiv:2504.15210},
year={ 2025 }
}