FLAMES Library for Vitis HLS

Flexible Linear Algebra with Matrix-Empowered Synthesis (for Vitis HLS)

Developed by Wuqiong Zhao and other contributors, from LEADS, Southeast University. This is part of the AutoHDW project.

Key Features

• Header-only Library (Super Easy to Install and Use)
• Templated-based C++ Design:
  • Mat and Tensor Classes
  • MatRef and MatView for Reference and View
  • (Relatively) Modern C++ Implementation (C++14/17)
• Hardware-friendly Design:
  • Optimized RAM Usage
  • Configurable Parallelism
  • Optimized Matrix Operations
• Fully Open Source

Read our paper for details (open access PDF).

Example

Linear algebra algorithm implementation made easy by FLAMES! Here is the NSA algorithm and the corresponding implementation using FLAMES:

| Step | Algorithm | FLAMES C++ Implementation | | :--: | -------------------------------------------- | ---------------------------------- | | 1 | $\mathbf{D} = \mathbf{A} \circ \mathbf{I}$ | auto D = A.diagMat_(); | | 2 | $\mathbf{E} = \mathbf{A} - \mathbf{D}$ | auto E = A.offDiag_(); | | 3 | $\mathbf{D}I = \mathbf{D}^{-1}$ | `auto DI = D.inv();| | 4 | $\mathbf{P} = -\mathbf{D}_I \mathbf{E}$ |auto P = -DI * E;| | 5 | $\mathbf{X} = \mathbf{P}$ (Iter. 1) |auto X = P = P;| | 6 | $\text{for } i = 2, \dots, n$ |for (int i = 2; i <= n; ++i) {| | 7 | $\quad \mathbf{P}^i = \mathbf{P}^{i-1} \mathbf{P}$ | P_ *= P;| | 8 | $\quad \mathbf{X} = \mathbf{X} + \mathbf{P}^i$ | X += P;| | 9 | $\text{end}$ |}` | | 10 | $\mathbf{A}^{-1} = \mathbf{X} \mathbf{D}I + \mathbf{D}I$ | `Ainv = X * DI + DI;` |

From Table 2 in our paper, code available at examples/mat-inv-nsa.

Citation

If you find FLAMES useful, please cite our paper: Flexible High-Level Synthesis Library for Linear Transformations, IEEE TCAS-II, vol. 71, no. 7, pp. 3348-3352, Jul. 2024. [IEEE Xplore] [PDF] [DOI] bibtex @article{zhao2024flexible, title = {Flexible High-Level Synthesis Library for Linear Transformations}, author = {Zhao, Wuqiong and Li, Changhan and Ji, Zhenhao and Guo, Zhichen and Chen, Xuanbo and You, You and Huang, Yongming and You, Xiaohu and Zhang, Chuan}, journal = {{IEEE} Transactions on Circuits and Systems {II}: Express Briefs}, volume = {71}, number = {7}, pages = {3348--3352}, year = {2024}, month = jul, publisher = {IEEE} }

Supported Versions

Since FLAMES is a modern library written using C++14 (with some C++17 features), it only supports Vitis HLS 2020 or later where the GCC compiler version is 6.2.0. Notably, Vivado HLS is not supported.

Usage

FLAMES is a header-only library, so you can easily use it by first cloning it under you project root with shell git clone https://github.com/autohdw/flames.git

Core Modules

You can include the required header ```cpp

include "flames/core.hpp"

All classes and functions are under the `flames` namespace, so you can use cpp using namespace flames; `` to access classesMat, etc. directly instead offlames::Mat`.

Additional Insights

You can find more information about FLAMES in FLAMES_Insight.pdf.

License

The FLAMES is open source and distributed by an Apache license (v2.0). Please cite our paper if you use FLAMES in your research.