llvm-cbe

resurrected LLVM "C Backend", with improvements

INSTALLATION INSTRUCTIONS

This version of the LLVM-CBE library works with LLVM 3.5.0. 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) and Mac OS X.

Step 1: Installing LLVM

LLVM-CBE relies on specific LLVM internals, and so it is best to use it with a specific revision of the LLVM development tree. Currently, llvm-cbe works with the LLVM 3.5.0 release version.

Note: to convert C to LLVM IR to run the tests, you will also need the clang compiler.

As llvm-cbe is a prototype library, we only use it with debugging enabled. A sample of commands to do that is as follows:

 cd $HOME
 git clone https://github.com/llvm-mirror/llvm
 cd llvm
 git checkout release_35
 ./configure
 make ENABLE_OPTIMIZED=0 DEBUG_SYMBOLS=1

Step 2: Compiling LLVM-CBE

Sample commands to download and compile llvm-cbe are:

cd $HOME/llvm/projects
git clone https://github.com/vtjnash/llvm-cbe.git llvm-cbe
cd ..
make ENABLE_OPTIMIZED=0 DEBUG_SYMBOLS=1

Step 3: Usage Examples

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

$ cd llvm/lib/test/selectionsort
$ ls
main.c
$ clang -S -emit-llvm main.c
$ ls
main.c main.ll
$ $(HOME)/llvm/Debug+Asserts/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