Skip to content
master
Go to file
Code
This branch is 55 commits ahead, 103 commits behind JuliaComputing:master.

Latest commit

 

Git stats

Files

Permalink
Failed to load latest commit information.
Type
Name
Latest commit message
Commit time
 
 
 
 
lib
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

README.md

llvm-cbe

The resurrected LLVM "C Backend", with improvements.

GOAL OF THIS FORK

My primary goal is to have a backend I can use for this project:

Github: https://github.com/Ace17/dscripten Blogpost: http://code.alaiwan.org/wp/?p=103 Demo: http://code.alaiwan.org/dscripten/full.html

In one word, it's a compiler from the D programming language to Javascript (asmjs).

The LLVM frontend for the D programming language, aka LDC, generates valid bitcode that JuliaComputing/llvm-cbe can't process (it generates uncompilable C code). (It seems that the JuliaComputing/llvm-cbe was only tested with bitcode inputs that were generated by clang)

Moreover, the project in its current state needs a lot of cleaning, its merely consists of one huge source file and uses heavy C++ syntax that isn't required anymore, and the test suite is hard to use.

So my goal here is to have a codebase:

  • that has no bugs blocking the dscripten project.
  • that works with a recent version of LLVM (at the moment 3.9, vs JuliaComputing/llvm-cbe which requires LLVM 3.7)
  • that can be compiled out of the LLVM tree (as long as there's one llvm-config in the PATH).
  • that has a trustable suite of tests which directly feed llvm-cbe with deterministic LLVM bitcode (instead of relying on clang code generation, as JuliaComputing/llvm-cbe does).
  • that don't require compromises on code cleanliness.
  • whose output is standard ISO C99 code, instead of relying on the specifics of some compilers.

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 1a: Installing LLVM manually

LLVM-CBE currently requires LLVM 3.9 to be installed somewhere on your system, and that the corresponding "llvm-config" be in your PATH. (only LLVM is needed, not clang).

The first step is to compile LLVM on your machine:

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

At this point, you should have llvm-config in your path:

$ llvm-config --version
3.9.1

Step 1b: Install LLVM from repositories

Alternatively, a LLVM installed some other way can be used, e.g. installing the Debian packages. Be aware that some distributions will suffix the 'llvm-config' program with LLVM version, e.g 'llvm-config-3.9'. In this case, you will need to set the environment variable LLVM_CONFIG so the makefile knows which program to call. Example:

$ export LLVM_CONFIG=llvm-config-3.9

Step 2: Compiling LLVM-CBE

Next, download and compile llvm-cbe:

$ cd $HOME
$ git clone https://github.com/JuliaComputing/llvm-cbe.git llvm-cbe
$ cd llvm-cbe
$ make

Step 3: Usage Examples

Once llvm-cbe is compiled, you can run it with the following command.

$ bin/llvm-cbe main.ll -o=main.cbe.c
$ gcc -w main.cbe.c -o main.exe
$ ./main.exe

Run the test suite

$ ./check

This will trigger the build and run the tests.

About

resurrected LLVM "C Backend", with improvements

Resources

License

Releases

No releases published
You can’t perform that action at this time.