llvm-cbe

LLVM 3.9 "C Backend", with improvements

INSTALLATION INSTRUCTIONS

This version of the LLVM-CBE library works with LLVM 3.9. You will have to compile this version of LLVM before you try to use LLVM-CBE. This guide will walk you through the compilation and installation of both tools and show usage statements to verify that the LLVM-CBE library is compiled correctly.

The library is known to compile on various Linux versions (Redhat, Mageia, Ubuntu, Debian), Mac OS X, and Windows (Mingw-w64).

Step 1: Installing GCC 4.8

Ubuntu 14.04

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.8
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 50

Step 2: Installing CMAKE 3.4.3 or higher

Ubuntu 14.04

LLVM/Clang 3.9 needs cmake 3.4.3 or higher, since Ubuntu does not have this natively, just install it from a binary package: (installed here in $HOME/progs)

wget https://cmake.org/files/v3.5/cmake-3.5.2-Linux-x86_64.tar.gz
tar -xf cmake-3.5.2-Linux-x86_64.tar.gz -C ~/progs
export PATH=~/progs/cmake-3.5.2-Linux-x86_64/bin:$PATH

sudo apt-get install clang-3.9 cmake
export CC=clang-3.9
export CXX=clang++-3.9

Step 3: Installing LLVM

The next step is to compile LLVM on your machine (this assumes an in-tree build, but out-of-tree will also work):

cd $HOME
git clone https://github.com/llvm-mirror/llvm
cd llvm
git checkout release_39

Step 4: Compiling LLVM-CBE

Next, download and compile llvm-cbe from the same folder:

cd $HOME/llvm/projects
git clone https://github.com/gapkalov/llvm-cbe.git llvm-cbe
cd $HOME/llvm/
mkdir build
cd build
cmake -G "Unix Makefiles" ..
make

Step 5: Run Tests

If llvm-cbe compiles, you should be able to run it with the following commands.

cd $HOME/llvm/projects/test
make clean
make

Step 6: Usage Examples

$ cd llvm/lib/test/selectionsort
$ ls
main.c
$ clang -S -emit-llvm main.c
$ ls
main.c main.ll
$ $(HOME)/llvm/Release/bin/llvm-cbe main.ll

Compile Generated C-Code and Run

$ gcc -o main.cbe main.cbe.c
$ ls
main.c  main.cbe  main.cbe.c  main.ll
$ ./main.cbe

Known Issues

1. Type uint64_t not genrated, now replaced to int64_t
2. local array is not generated correctly
3. APInt-c.cpp not compiled
4. Warning as error now disabled
5. Test 86 - disabled
6. Test 87 - disabled
7. Too much FIX ME in the code ;)