BitHAA Front-End Sub-system

This repository contains a version of BitHAA's front-end section. Here, we will instruct the readers on how to convert their normal calculations into BitSliced ones. Note that this is not the final version of our Front-End, but the difference is negligible. Instructions on installation, building, and running this module are given.

This image was shown in the article in order to further demonstrate the Front-End's workflow:

Prerequisites

You only need to clone the LLVM project:

$ git clone https://github.com/llvm/llvm-project.git

Building LLVM

Here you need to create the LLVM's .build folder:

$ mkdir .build
$ cd .build
$ cmake -G "Ninja" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_USE_LINKER=gold -DLLVM_PARALLEL_LINK_JOBS=2 ../llvm-project/llvm
$ ninja -j8 all

(Optional) You can set environment variables in order to make the next steps. Something like this could be done:

$ export LLVM_PATH=<Path to llvm-project folder>
$ export PROJECT_PATH=<Path to our code>

Building your application

Start writing your libraries in the lib folder. Two sample libraries are shown in the lib folder of this repo.

$ export LLVM_DIR=/${BUILD_PATH}/lib/cmake/llvm/
$ cd ${PROJECT_PATH}
$ mkdir .build
$ cd .build
$ cmake -G "Ninja" ../
$ ninja

After this, the plugins are ready to be used in the .build/lib/ folder as *.so files.

Usage

Create your input files in the inputs folder. Then, follow these commands to produce your object files. Note that our you need to replace some names in the following code.

$ cd ${PROJECT_PATH}/inputs
$ /${LLVM_PATH}/.build/bin/clang -emit-llvm -S -O1 <INPUT_FILENAME.c>
$ /${LLVM_PATH}/.build/bin/opt -load-pass-plugin <../.build/lib/DESIRED_LIB.so> -passes=<Pass Name> <INPUT_FILENAME.ll> -S -o <OUTPUT_FILENAME.ll>

Now, your object files are ready to use in the inputs folder.

In this repository, we have provided an example of vectorized add/sub to help readers understand the procedure by running the code. Note that these two operations are for demonstration purposes, and we will provide our complete and final Front-End in our open-source tool.