TomasuLLM: Out-of-Order Speculative Execution for LLM Agents

Abstract:Long-running tools can dominate coding-agent latency: compilers, test suites, and repository commands take seconds to minutes while the agent idles. This observation stall presents the same tension that drove out-of-order processors -- asequential interface hides work that can be predicted and started early, but a speculative result may become visible only after it and every earlier step have been validated. We present TomasuLLM, a runtime that executes agent tool calls out of trajectory order while preserving task-execution correctness. It drafts future actions, runs them in isolated copy-on-write sandboxes, traces their dependencies and effects, and commits results in trajectory order only after validation against committed state. Across three benchmarks spanning sub-second to minutes-long tool calls, TomasuLLM improves the reported benchmark means and scales with tool latency: 1.31x on 100 SWE-bench Verified tasks, 1.35x on 28 Terminal-Bench 2.0 tasks, and 1.27x matched progress on 18 SWE-Marathon sessions. Across 4,010 audited commit-validation records, it produces zero false accepts.

Computation and Language (cs.CL); Operating Systems (cs.OS); Software Engineering (cs.SE)

arXiv:2609.38201 [cs.CL]

(or arXiv:2609.38201v1 [cs.CL] for this version)

https://doi.org/10.48550/arXiv.2609.38201 Focus to learn more arXiv-issued DOI via DataCite

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