DFCIR (DataFlow Computer Intermediate Representation)

DFCIR is an intermediate representation based on LLVM MLIR project for high-level synthesis of streaming dataflow computers.

It utilizes high-level abstract concepts like Streams, Scalars, Kernels to represent the computational logic of a streaming dataflow computer. Currently

Currently DFCIR is supposed to be used in conjunction with FIRRTL intermediate representation from CIRCT project to generate SystemVerilog-designs for streaming dataflow computers.

The computational logic of a streaming dataflow computer has to be statically scheduling: DFCIR currently has two implementations of scheduling algorithms (Linear Programming-approach and a simple as-soon-as-possible algorithm).

Prerequisites

[!!!] Current version was tested only on Ubuntu 20.04 [!!!]

In order to build DFCIR a number of dependencies has to be installed:

• build-essential
• clang + lld or g++ + gcc as a C/C++ compiler
• liblpsolve55-dev
• ninja-build (preferred) or make

This can be done using the following command:

sudo apt install build-essential clang lld g++ gcc liblpsolve55-dev ninja-build make

Prerequisites (CIRCT)

Additionally, one of the CIRCT libraries' releases is required (releases).

[!!!]Currently supported release: 1.72.0, Apr 5 2024 (link)[!!!]

Note that it's the libraries that are required, not the binary executables.
Look for the archives which have the following names: circt-full-static-<ARCH> or circt-full-shared-<ARCH> for static and dynamic libraries respectively.

[!!!]Current releases have an inconsistency in their configuration files[!!!]:
after downloading the chosen release archive, extract the files inside and look for the file lib/cmake/mlir/MLIRTargets.mlir.

Open MLIRTargets.mlir with a text editor of your choice and look the _NOT_FOUND_MESSAGE_targets near the end of the file:
for 1.72.0, it's line 3012 for circt-full-static-linux-x64-archive and line 3008 for circt-full-shared-linux-x64.tar-archive.

Remove all the "CIRCT*"-entries from the corresponding foreach-statement and save the file.

Building DFCIR

DFCIR is a CMake package, so in order to build it a simple CMake environment has to be set up.

DFCIR needs to know the location which the chosen release archive was extracted to and the full path to this location has to be passed to CMake environment in the form of CIRCT_BIN_HOME CMake variable:

assuming CIRCT-archive was downloaded in home directory (~) and was extracted using tar -xvf, thus firtool-1.72.0 (the directory with the top-level CMakeLists.txt-file) is also in the home directory, the CMake environment can be set up using the following commands:

cd <DFCIR_DIR>
mkdir build
cd build
cmake .. -G Ninja -DCIRCT_BIN_HOME="~/firtool-1.72.0"

After this, use cmake --build . to build DFCIR.

Usage of DFCIR

Currently DFCIR project is concentrated in a single static library - a CMake target, addressed by its alias DFCIR::MLIRDFCIR. Using CMake find_package(REQUIRED CONFIG HINTS)-functionality, this library can be incorporated in other projects (the full path after HINTS needs to specify the build-directory for DFCIR).

The following code describes a simple CMakeLists.txt-file of a project, using DFCIR:

cmake_minimum_required(VERSION 3.16 FATAL_ERROR)
project(TESTPROJECT C CXX)
set(CMAKE_CXX_STANDARD 17)

find_package(DFCIR REQUIRED CONFIG HINTS "~/DFCIR/build")

add_executable(TEST test.cpp)
target_link_libraries(TEST DFCIR::MLIRDFCIR)