🤖 AI Summary
This work addresses the interoperability challenge between GCC and LLVM compiler intermediate representations (IRs), which stems from their semantic and structural differences. To bridge this gap, the authors propose IRIS-14B, the first large language model specifically designed for IR-to-IR translation. Built upon a 14-billion-parameter Transformer architecture, IRIS-14B leverages supervised fine-tuning to learn the mapping between GIMPLE and LLVM IR derived from the same C source code, enabling high-fidelity automatic translation. Experimental results demonstrate that IRIS-14B substantially outperforms existing open-source large models on real-world C programs and competitive programming tasks, achieving up to a 44-percentage-point improvement in accuracy. This study provides the first empirical validation of large language models as effective and feasible interoperability layers within neuro-symbolic hybrid compilation frameworks.
📝 Abstract
GCC and LLVM underpin much of modern software infrastructure, relying on distinct Intermediate Representations (IRs) to drive optimizations and code generation. However, the semantic and structural differences between these IRs create significant barriers for cross-toolchain interaction, limiting the reuse of compiler frontends, backends, and optimization pipelines across programming languages and compilation ecosystems. Traditional rule-based translators have attempted to bridge this gap, but their complexity and maintenance cost have hindered practical adoption. In this context, Large Language Models (LLMs) appear to be an emerging technology that offers a data-driven alternative, capable of learning complex mappings between heterogeneous compiler IRs directly from sufficiently representative examples. To explore this approach, this paper presents IRIS-14B, a 14-billion-parameter transformer model fine-tuned to translate GIMPLE (as emitted by GCC) to LLVM IR (as emitted by LLVM). The model is trained on paired IRs extracted from C sources and evaluated on the GIMPLE-to-LLVM IR transformation applied to IRs derived from real-world C code and competitive programming problems. To the best of our knowledge, IRIS-14B is the first model trained explicitly for IR-to-IR translation. It outperforms the accuracy of widely used models, including the largest state-of-the-art open models available today, ranging from 13 to 1,000 billion parameters, by up to 44 percentage points. The proposed transformation supports the integration of LLMs as complementary components within hybrid neuro-symbolic compiler architectures, where models such as IRIS-14B act as interoperability layers enabling cross-toolchain workflows without modifying existing compiler passes, while traditional compiler infrastructure continues to perform deterministic compilation and optimization.