README.md

Revec: Program Rejuvenation through Revectorization

This is a fork of the LLVM repository that implements Revec, an IR-level pass that retargets vectorized code between processor generations. In general, revectorization is our proposed task of recompiling non-portable vectorized code to leverage higher bitwidth instruction sets on newer architectures.

For details of the pass, please see Revec: Program Rejuvenation through Revectorization.

Citation: (* denotes equal contribution)

Charith Mendis *, Ajay Jain *, Paras Jain, and Saman Amarasinghe. 2019. Revec: Program Rejuvenation through Revectorization. In Proceedings of the 28th International Conference on Compiler Construction (CC ’19), February 16–17, 2019, Washington, DC, USA. ACM, New York, NY, USA, 13 pages.

Compiling LLVM and Clang with Revec

Install Clang-6.0, CMake, and Ninja to build our modified version of LLVM/Clang:

sudo apt-get update
sudo apt-get install llvm-6.0 clang-6.0 cmake ninja-build

Clone LLVM and Clang with the Revectorizer pass:

cd $ROOTDIR
git clone git@github.com:revec/llvm-revec.git llvm

cd $ROOTDIR/llvm/tools
git clone git@github.com:revec/clang-revec.git clang

cd $ROOTDIR/llvm/tools/clang
git clone git@github.com:llvm-mirror/clang-tools-extra.git extra

cd $ROOTDIR/llvm/projects
git clone git@github.com:llvm-mirror/libcxx.git
git clone git@github.com:llvm-mirror/libcxxabi.git
git clone git@github.com:llvm-mirror/compiler-rt.git

Build Clang:

mkdir $ROOTDIR/build
cd $ROOTDIR/build
CXX=clang++-6.0 CC=clang-6.0 cmake -G Ninja ../llvm -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_USE_LINKER=gold -DLLVM_TARGETS_TO_BUILD="X86"
ninja clang