Execution-Grounded Credit Assignment for GRPO in Code Generation
On the map: LLM reasoning → Reinforcement learning for reasoning
Abstract (arXiv)
Critic-free reinforcement learning with verifiable rewards (RLVR) improves code generation by optimizing unit-test pass rates, but GRPO-style updates suffer from coarse credit assignment: a single outcome signal is spread uniformly across long programs even when failure stems from a localized semantic error. We propose Execution-Grounded Credit Assignment (EGCA), which localizes GRPO updates using execution traces. For programs that satisfy algorithmic constraints but fail tests, EGCA executes the candidate and a canonical reference solution (curated once offline; used for analysis, not supervision) under identical instrumentation, identifies the earliest semantic divergence, and assigns advantage only to the corresponding token span while masking downstream tokens. EGCA is a drop-in modification requiring no critic, auxiliary loss, or learned verifier, yielding 82.1% pass@1 on HumanEval (+3.1 over GRPO) and 68.9% on MBPP (+1.5) with 18% wall-clock overhead.
Key facts. Cited by 5 papers in the map (data through 7 Oct 2026). Placed in Reinforcement learning for reasoning, one of 17 directions in LLM reasoning. Builds on 9 of its 16 references that are in the map. First posted on arXiv 17 Mar 2026.
Builds on
9 of 16 references.
Closest ancestors · 2
Same direction, newest first
- 2025Exploiting Tree Structure for Credit Assignment in RL Training of LLMs22 Sep
- 2023Let's Verify Step by Step31 May
Other references · 7
- 2024DeepSeekMath: Pushing the Limits of Mathematical Reasoning in Open Language Modelscited by 8,851
- 2021Evaluating Large Language Models Trained on Codecited by 8,053
- 2021Program Synthesis with Large Language Modelscited by 3,509
- 2024DeepSeek-Coder: When the Large Language Model Meets Programming -- The Rise of Code Intelligencecited by 1,154
- 2024Qwen2.5-Coder Technical Reportcited by 1,151
- 2023Execution-based Code Generation using Deep Reinforcement Learningcited by 95
- 2025CodeRL+: Improving Code Generation via Reinforcement with Execution Semantics Alignmentcited by 22
Built on by
Citing papers per year: 2026: 5.
5 papers.
- 2026Unifying Group-Relative and Self-Distillation Policy Optimization via Sample Routingcited by 65
- 2026Knowing When to Ask: Segment-Level Credit Assignment for LLM Tool Usecited by 2
- 2026DRIFT: Difficulty Routing Self-DIstillation with Rhythm-Gated Exploration and Success BuFfer Trainingcited by 2
- 2026MoRSE: Task-Oriented Multi-Agent System with Mixture of Role-Subtask Expertscited by 2
- 2026When Implausible Tokens Get Reinforced: Tail-Aware Credit Calibration for LLM Reinforcement Learningcited by 1
- 2026MoRSE: Task-Oriented Multi-Agent System with Mixture of Role-Subtask Experts10 Aug 2026
- 2026When Implausible Tokens Get Reinforced: Tail-Aware Credit Calibration for LLM Reinforcement Learning8 Jul 2026
- 2026DRIFT: Difficulty Routing Self-DIstillation with Rhythm-Gated Exploration and Success BuFfer Training29 Jun 2026
- 2026Knowing When to Ask: Segment-Level Credit Assignment for LLM Tool Use27 May 2026
- 2026Unifying Group-Relative and Self-Distillation Policy Optimization via Sample Routing2 Apr 2026
Similar, not cited
Close in wording, no citation either way
- 2025MURPHY: Feedback-Aware GRPO with Retrospective Credit Assignment for Multi-Turn Code Generation
- 2026ExecuCritic: Calibrated Critic Shaping for Code Generation with Verifiable Rewards ↗
- 2026StepCodeReasoner: Aligning Code Reasoning with Stepwise Execution Traces via Reinforcement Learning
- 2026Rubric-to-Code Credit Assignment for Reinforcement Learning
- 2026BoT-GRPO: Efficient Process-Reward RL for Reasoning via Bag-of-Token Aggregation
- 2025From Reasoning to Code: GRPO Optimization for Underrepresented Languages
- 2026Reinforcement Learning for Code Optimization
- 2025Afterburner: Reinforcement Learning Facilitates Self-Improving Code Efficiency Optimization