2025/02/20 by Dacheng Li, Shiyi Cao, Li, Dacheng +15 · 1 voice · 46 citations
Computer Science · Engineering · #Artificial Intelligence (cs.AI) #Embedded Systems Design Techniques #FOS: Computer and information sciences #Machine Learning (cs.LG) #Real-time simulation and control systems #Software Testing and Debugging Techniques #cs.AI #cs.LG
paper · pdf · doi:10.48550/arxiv.2502.14382
openalex publication_date 2025/02/20 · arxiv published 2025/02/20 · arxiv updated 2025/02/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Increasing test-time compute for LLMs shows promise across domains but remains underexplored in code generation, despite extensive study in math. In this paper, we propose S*, the first hybrid test-time scaling framework that substantially improves the coverage and selection accuracy of generated code. S* extends the existing parallel scaling paradigm with sequential scaling to push performance boundaries. It further leverages a novel selection mechanism that adaptively generates distinguishing inputs for pairwise comparison, combined with execution-grounded information to robustly identify correct solutions. We evaluate across 12 Large Language Models and Large Reasoning Model and show: (1) S* consistently improves performance across model families and sizes, enabling a 3B model to outperform GPT-4o-mini; (2) S* enables non-reasoning models to surpass reasoning models - GPT-4o-mini with S* outperforms o1-preview by 3.7% on LiveCodeBench; (3) S* further boosts state-of-the-art reasoning models - DeepSeek-R1-Distill-Qwen-32B with S* achieves 85.7% on LiveCodeBench, approaching o1 (high) at 88.5%. Code will be available under https://github.com/NovaSky-AI/SkyThought.