LACE: Large Language Model Aided Multi-Agent Framework for Agile RISC-V Instruction Extension

Abstract:Domain-specific Instruction Set Architecture eXtensions (ISAX) are widely adopted in the RISC-V ecosystem to accelerate emerging workloads, but implementing and validating ISAXes across different cores remains slow and fragmented. Existing frameworks still require per-core interface adaptation, and differential testing often breaks once either the microarchitecture or the ISAX changes. We present LACE, an LLM-aided multi-agent workflow that translates natural-language ISAX intents into a compact two-level IR (operation-level and HDL task-level), performs retrieval-guided localized RTL edits over large repositories, and closes the loop with a compiler-agnostic riscv-formal checking flow (assuming RVFI availability or instrumentation). Across four embedded RISC-V cores, LACE raises pass@1 generation accuracy from near-zero to 72.8\% within our evaluation setup, while improving code localization and reducing integration rework. The code of LACE is available at this https URL.

Hardware Architecture (cs.AR); Computation and Language (cs.CL); Software Engineering (cs.SE)

arXiv:2608.02915 [cs.AR]

(or arXiv:2608.02915v1 [cs.AR] for this version)

https://doi.org/10.48550/arXiv.2608.02915 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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