Futhark

Futhark is a purely functional data-parallel programming language. Its optimising compiler is able to compile it to typically very performant GPU code. The language and compiler is developed as part of the HIPERFIT project at DIKU. The project is still research-quality, and the focus has mostly been on ensuring high runtime-performance, so the source language still lacks many niceties for manual programming - it is fairly usable as a target for high-level code generation, however.

For more information, see the website.

The incomplete documentation is here.

Installation

You are strongly recommended to use Stack for building the Futhark compiler from scratch. It avoids many of the problems usually associated with the older Haskell build tool, cabal-install. This section describes how to use Stack.

To get all the prerequisites for building the Futhark compiler (including, if necessary, the appropriate version of the Haskell compiler), run:

stack setup

Note that this will not install anything system-wide and will have no effect outside the Futhark build directory. Now you can run the following command to build the Futhark compiler, including all dependencies:

stack build

The Futhark compiler and its tools will now be built. You can install it to your $HOME/.local/bin by running:

stack install

Make sure this directory is in your $PATH. Alternatively, just copy the binaries where you need them.

Installation with cabal-install

Using Stack, as described in the previous section, is strongly recommended.

You will need GHC 7.8 or newer and a recent version of Alex to compile Futhark.

Just run cabal install and executables by the names of futhark, futhark-c, futhark-opencl and futharki will be installed in your Cabal bin directory, most likely $HOME/.cabal/bin.

Otherwise, just run cabal configure, followed by cabal build, and the executable can be found in dist/build/futhark/futhark.

You can get a sufficiently new version of Alex by running cabal install alex if $HOME/.cabal/bin is in your $PATH. If you accidentally try (and fail) to install Futhark with an older version of Alex, you will need to run cabal clean to ensure that the broken build artifacts will not interfere with the new build.

Make sure that you have a recent Cabal to go with your GHC. A common mistake is to only upgrade GHC, but use an old Cabal (i.e. older than 1.20; check with cabal --version). If you compile some of the dependencies with an old Cabal by mistake, and then fail later in the process, you will have to delete your ~/.ghc directory to remove the broken libraries.

Usage

To compile a Futhark program to sequential C:

futhark-c prog.fut -o prog

Or maybe OpenCL:

futhark-opencl prog.fut -o prog

And then run it:

./prog < prog.input

To interpret a Futhark program:

futharki prog.fut < prog.input

Hacking

We try to make use of Github issues for organising our work.

For every commit, Futhark is automatically built and tested on Travis.

Testing

Run the data/runtests.sh script to check how well we're doing. Use data/runtests.sh -t if you're in a hurry and only want the test suite to do type checking.