This paper proposes ISDC, a novel feedback-guided iterative system of difference constraints (SDC) scheduling algorithm for high-level synthesis (HLS). ISDC leverages subgraph extraction-based low-level feedback from downstream tools like logic synthesizers to iteratively refine HLS scheduling. Technical innovations include: (1) An enhanced SDC formulation that effectively integrates low-level feedback into the linear-programming (LP) problem; (2) A fanout and window-based subgraph extraction mechanism driving the feedback cycle; (3) A no-human-in-loop ISDC flow compatible with a wide range of downstream tools and process design kits (PDKs). Evaluation shows that ISDC reduces register usage by 28.5% against an industrial-strength open-source HLS tool.
@article{arxiv.2401.12343,
title = {Subgraph Extraction-based Feedback-guided Iterative Scheduling for HLS},
author = {Hanchen Ye and David Z. Pan and Chris Leary and Deming Chen and Xiaoqing Xu},
journal= {arXiv preprint arXiv:2401.12343},
year = {2024}
}