# TicTacBench: Benchmarking Timing Closure Capabilities of Coding Agents

arXiv: https://arxiv.org/abs/2609.23363 · HTML: https://mlsanity.com/paper/2609.23363/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Placed in Software engineering coding agents, one of 16 directions in LLM agents and tool use.
- Builds on 18 of its 25 references that are in the map.
- First posted on arXiv 20 Sep 2026.

## Placed in

- LLM agents and tool use / [Software engineering coding agents](https://mlsanity.com/agents/software-engineering-coding-agents/)

## Builds on (most cited first, 18 of 18)

- [Qwen3 Technical Report](https://mlsanity.com/paper/2505.09388/) (2025)
- [SWE-bench: Can Language Models Resolve Real-World GitHub Issues?](https://mlsanity.com/paper/2310.06770/) (2023)
- [DeepSeek-V4: Towards Highly Efficient Million-Token Context Intelligence](https://mlsanity.com/paper/2606.19348/) (2026)
- [GLM-5: from Vibe Coding to Agentic Engineering](https://mlsanity.com/paper/2602.15763/) (2026)
- [Kimi K2: Open Agentic Intelligence](https://mlsanity.com/paper/2507.20534/) (2025)
- [VerilogEval: Evaluating Large Language Models for Verilog Code Generation](https://mlsanity.com/paper/2309.07544/) (2023)
- [The MiniMax-M2 Series: Mini Activations Unleashing Max Real-World Intelligence](https://mlsanity.com/paper/2605.26494/) (2026)
- [Revisiting VerilogEval: A Year of Improvements in Large-Language Models for Hardware Code Generation](https://mlsanity.com/paper/2408.11053/) (2024)
- [Comprehensive Verilog Design Problems: A Next-Generation Benchmark Dataset for Evaluating Large Language Models and Agents on RTL Design and Verification](https://mlsanity.com/paper/2506.14074/) (2025)
- [RTLRewriter: Methodologies for Large Models aided RTL Code Optimization](https://mlsanity.com/paper/2409.11414/) (2024)
- [OpenLLM-RTL: Open Dataset and Benchmark for LLM-Aided Design RTL Generation](https://mlsanity.com/paper/2503.15112/) (2025)
- [RTL-Repo: A Benchmark for Evaluating LLMs on Large-Scale RTL Design Projects](https://mlsanity.com/paper/2405.17378/) (2024)
- [SymRTLO: Enhancing RTL Code Optimization with LLMs and Neuron-Inspired Symbolic Reasoning](https://mlsanity.com/paper/2504.10369/) (2025)
- [E-Syn: E-Graph Rewriting with Technology-Aware Cost Functions for Logic Synthesis](https://mlsanity.com/paper/2403.14242/) (2024)
- [A New Benchmark for the Appropriate Evaluation of RTL Code Optimization](https://mlsanity.com/paper/2601.01765/) (2026)
- [IR-Aware ECO Timing Optimization Using Reinforcement Learning](https://mlsanity.com/paper/2402.07781/) (2024)
- [INVICTUS: Optimizing Boolean Logic Circuit Synthesis via Synergistic Learning and Search](https://mlsanity.com/paper/2305.13164/) (2023)
- [ViTAD: Timing Violation-Aware Debugging of RTL Code using Large Language Models](https://mlsanity.com/paper/2508.13257/) (2025)

## Abstract (arXiv)

Recent advances in large language models (LLMs) have led to the emergence of coding agents capable of performing complex engineering tasks, including register-transfer level (RTL) design and optimization. Existing RTL benchmarks mainly evaluate functional correctness and performance, power, and area (PPA) of the generated RTL designs, leaving agents' ability for timing closure under-evaluated. We propose TicTacBench, a benchmark specifically designed to evaluate coding agents' capabilities for RTL-level timing closure under post-place-and-route (post-PnR) evaluation. TicTacBench contains 30 diverse tasks, each provided with a suboptimal RTL design, realistic timing constraints, functional equivalence verification, and timing reports. With over 300 runs of coding agents driven by 8 frontier LLMs, we find that even the best agent can only close 53.3% of tasks with 7.18% area-delay product (ADP) degradation and 8.83% energy-delay-squared product (EDDP) improvement on average. We identify common failure categories that explain why agents fail to close timing. Then we propose TicTacSkill, a new method that guides agents to follow standard timing-closure procedures and improves the Timing Closure Rate by 9%. These results suggest that while coding agents have made significant progress in RTL design, their timing-closure capability still has substantial room for improvement.