2020.2 Vitis™ Application Acceleration Tutorials

See 2020.1 Tutorials

Vitis HLS Analysis and Optimization

Introduction

Vitis High-Level Synthesis (HLS) is a key part of the Vitis application acceleration development flow. The tool is responsible for compiling C/C++ and OpenCL code into a kernel for acceleration in the programmable logic (PL) region of Xilinx devices. Thus, it is the tool that compiles the hardware kernels for the Vitis tools by performing high-level synthesis.

TIP: Vitis HLS can also be used to generate Vivado IP from C/C++ code, but that flow is not the subject of this tutorial. Although similar, there are some significant differences between producing Vitis XO kernels and Vivado RTL IP. However, you can use this tutorial as a general introduction to the Vitis HLS tool.

In this tutorial, you will work through the Vitis HLS tool GUI to build, analyze, and optimize a hardware kernel. You are working through the Vitis kernel flow in the Vitis tool. For more information, refer to Enabling the Vitis Kernel Flow in the Vitis HLS Flow of the Vitis Unified Software Platform Documentation (UG1416).

Before You Begin

The labs in this tutorial use:

  • BASH Linux shell commands.

  • 2020.2 Vitis core development kit release and the xilinx_u200_xdma_201830_2 platform. If necessary, it can be easily ported to other versions and platforms.

IMPORTANT:

  • Before running any of the examples, make sure you have installed the Vitis core development kit as described in Installation in the Application Acceleration Development flow of the Vitis Unified Software Platform Documentation (UG1416).

  • If you run applications on the Xilinx® Alveo™ Data Center accelerator cards, ensure the card and software drivers have been correctly installed by following the instructions To complete installation, follow the instructions on the Alveo Product Documentation tab.

Setup the environment to run Vitis

To configure the environment to run Vitis, run the following scripts which set up the environment to run in a specific command shell.

source <Vitis_install_path>/Vitis/2020.2/settings64.sh
source /opt/xilinx/xrt/setup.sh

NOTE: .csh scripts are also provided but this tutorial assumes a bash shell is used.

To specify the location of any Data-Center or Embedded platforms you have installed, set the following environment variable:

export PLATFORM_REPO_PATHS=<path to platforms>

NOTE: On some Ubuntu distributions, you must also export LIBRARY_PATH to properly set up Vitis.

export LIBRARY_PATH=/usr/lib/x86_64-linux-gnu

For more information see Xilinx AR 73698.

Accessing the Tutorial Reference Files

  1. To access the reference files, type the following into a terminal: git clone https://github.com/Xilinx/Vitis-Tutorials.

  2. Navigate to the Getting_Started/Vitis_HLS directory, and then access the reference-files directory.