arXiv subjects

Callie Hao

Publications and source records attributed to Callie Hao.

4 recordsLinked to original sources

arXiv2026

HLSFactory-Agent: Large-Scale Agentic HLS Dataset Construction from Academic and Open-Source Projects

Building large, diverse datasets of high-level synthesis (HLS) designs beyond common community benchmarks remains an open challenge. This challenge is made urgent by the rise of deep learning and LLMs for hardware design, which demand such datasets to train QoR models and benchmark LLMs on HLS tasks. Despite ongoing efforts to broaden sources, dataset curation still depends on manual work: locating HLS designs across academic publications and open source, then extracting standalone designs from larger codebases. The process is error-prone and demands expert knowledge, iterative testing, and substantial per-repository engineering. To address this, we present HLSFactory-Agent, an LLM agent that automates large-scale HLS dataset curation by extracting standalone designs from larger codebases. HLSFactory-Agent runs the open-source Pi agent framework inside Docker containers to build and evaluate each extracted design. This turnkey automation allows users to pass a GitHub link or code directory to HLSFactory-Agent and receive a folder of extracted HLS designs ready to be integrated into the HLSFactory dataset framework. Additionally, we provide open-source scripts to scrape and index papers from computer architecture, EDA, and FPGA conferences that possibly implement or use HLS designs, allowing for faster human discovery and curation of HLS designs for HLSFactory-Agent. We report initial results from running HLSFactory-Agent across a small subset of our indexed repositories, demonstrating successful extraction of synthesizable designs from structured codebases. We open source HLSFactory-Agent and indexing scripts at https://github.com/sharc-lab/hlsfactory-agent.

cs.AR↗

arXiv2026

Benchmarking Agentic HLS Design Tasks With HLS-Eval

Large language models (LLMs) and AI agents are increasingly explored for hardware design, including high-level digital design. While most work targets code generation and editing for hardware description languages (HDLs), our prior work introduced HLS-Eval, an open-source benchmark for evaluating LLMs on high-level synthesis (HLS) design tasks. Those evaluations, however, focused on zero-shot generation and editing, leaving open how agents achieve HLS design tasks. We therefore extend HLS-Eval with an agentic evaluation flow built on the open-source mini-swe-agent framework. The flow lets HLS design agents use file-editing tools, invoke a C++ compiler for self-verification, and iteratively refine designs during inference, while logging agent traces for analysis of cost, token usage, and iteration count. We present initial results on the existing HLS-Eval benchmarks. In our initial evaluation, we find open-source LLMs paired with an agentic harness solve every simple HLS code generation task in our evaluation, underscoring the need to expand benchmark difficulty as model capabilities advance. Analyzing traces from passing and failing runs, we show how model size, token usage, and trajectory length relate to design pass rates. These results establish a foundation for agentic HLS design and motivate harder benchmarks and new agentic tooling as model capabilities progress.

cs.AR↗

arXiv2025

FIFOAdvisor: A DSE Framework for Automated FIFO Sizing of High-Level Synthesis Designs

Dataflow hardware designs enable efficient FPGA implementations via high-level synthesis (HLS), but correctly sizing first-in-first-out (FIFO) channel buffers remains challenging. FIFO sizes are user-defined and balance latency and area-undersized FIFOs cause stalls and potential deadlocks, while oversized ones waste memory. Determining optimal sizes is non-trivial: existing methods rely on restrictive assumptions, conservative over-allocation, or slow RTL simulations. We emphasize that runtime-based analyses (i.e., simulation) are the only reliable way to ensure deadlock-free FIFO optimization for data-dependent designs. We present FIFOAdvisor, a framework that automatically determines FIFO sizes in HLS designs. It leverages LightningSim, a 99.9\% cycle-accurate simulator supporting millisecond-scale incremental runs with new FIFO configurations. FIFO sizing is formulated as a dual-objective black-box optimization problem, and we explore heuristic and search-based methods to characterize the latency-resource trade-off. FIFOAdvisor also integrates with Stream-HLS, a framework for optimizing affine dataflow designs lowered from C++, MLIR, or PyTorch, enabling deeper optimization of FIFOs in these workloads. We evaluate FIFOAdvisor on Stream-HLS design benchmarks spanning linear algebra and deep learning workloads. Our results reveal Pareto-optimal latency-memory frontiers across optimization strategies. Compared to baseline designs, FIFOAdvisor achieves much lower memory usage with minimal delay overhead. Additionally, it delivers significant runtime speedups over traditional HLS/RTL co-simulation, making it practical for rapid design space exploration. We further demonstrate its capability on a complex accelerator with data-dependent control flow. Code and results: https://github.com/sharc-lab/fifo-advisor

cs.AR↗

arXiv2024

Accurate Low-Degree Polynomial Approximation of Non-polynomial Operators for Fast Private Inference in Homomorphic Encryption

As machine learning (ML) permeates fields like healthcare, facial recognition, and blockchain, the need to protect sensitive data intensifies. Fully Homomorphic Encryption (FHE) allows inference on encrypted data, preserving the privacy of both data and the ML model. However, it slows down non-secure inference by up to five magnitudes, with a root cause of replacing non-polynomial operators (ReLU and MaxPooling) with high-degree Polynomial Approximated Function (PAF). We propose SmartPAF, a framework to replace non-polynomial operators with low-degree PAF and then recover the accuracy of PAF-approximated model through four techniques: (1) Coefficient Tuning (CT) -- adjust PAF coefficients based on the input distributions before training, (2) Progressive Approximation (PA) -- progressively replace one non-polynomial operator at a time followed by a fine-tuning, (3) Alternate Training (AT) -- alternate the training between PAFs and other linear operators in the decoupled manner, and (4) Dynamic Scale (DS) / Static Scale (SS) -- dynamically scale PAF input value within (-1, 1) in training, and fix the scale as the running max value in FHE deployment. The synergistic effect of CT, PA, AT, and DS/SS enables SmartPAF to enhance the accuracy of the various models approximated by PAFs with various low degrees under multiple datasets. For ResNet-18 under ImageNet-1k, the Pareto-frontier spotted by SmartPAF in latency-accuracy tradeoff space achieves 1.42x ~ 13.64x accuracy improvement and 6.79x ~ 14.9x speedup than prior works. Further, SmartPAF enables a 14-degree PAF (f1^2 g_1^2) to achieve 7.81x speedup compared to the 27-degree PAF obtained by minimax approximation with the same 69.4% post-replacement accuracy. Our code is available at https://github.com/EfficientFHE/SmartPAF.

cs.CR↗