Code LLMs still struggle with code execution reasoning, especially in smaller models. Existing methods rely on supervised fine-tuning (SFT) with teacher-generated explanations, primarily in two forms: (1) input–output (I/O) prediction chains and (2) natural-language descriptions of execution traces. However, intermediate execution steps cannot be explicitly verified during SFT, so the training objective can reduce to merely matching teacher explanations. Moreover, training data is typically collected without explicit control over task difficulty. We introduce ExecVerify, which goes beyond text imitation by incorporating verifiable white-box rewards derived from execution traces, including next-statement prediction and variable value/type prediction. Our work first builds a dataset with multiple difficulty levels via constraint-based program synthesis. Then, we apply reinforcement learning (RL) to reward correct answers about both intermediate execution steps and final outputs, aligning the training objective with semantic correctness at each execution step. Finally, we adopt a two-stage training pipeline that first enhances execution reasoning and then transfers to code generation. Experiments demonstrate that a 7B model trained with ExecVerify achieves performance comparable to 32B models on code reasoning benchmarks and improves pass@1 by up to 5.9% on code generation tasks over strong post-training baselines.

The multilingual capabilities of large language models (LLMs) have attracted considerable attention over the past decade. Assessing the accuracy with which LLMs provide answers in multilingual contexts is essential for determining their level of multilingual proficiency. Nevertheless, existing multilingual benchmarks generally reveal severe drawbacks, such as overly translated content (translationese), the absence of difficulty control, constrained diversity, and disciplinary imbalance, making the benchmarking process unreliable and showing low convincingness. To alleviate those shortcomings, we introduce NOVA-63 (Native Omni-lingual Versatile Assessments of 63 Disciplines), a comprehensive, difficult multilingual benchmark featuring 93,536 questions sourced from native speakers across 14 languages and 63 academic disciplines. Leveraging a robust pipeline that integrates LLM-assisted formatting, expert quality verification, and multi-level difficulty screening, NOVA-63 is balanced on disciplines with consistent difficulty standards while maintaining authentic linguistic elements. Extensive experimentation with current LLMs has shown significant insights into cross-lingual consistency among language families, and exposed notable disparities in models’ capabilities across various disciplines. This work provides valuable benchmarking data for the future development of multilingual models. Furthermore, our findings underscore the importance of moving beyond overall scores and instead conducting fine-grained analyses of model performance.