This plugin gives an example of defining a compiler plugin for GHC. You mark functions with annotations which the compiler the unrolls or peels to some threshold.
Install the latest version of the plugin from Hackage (requires GHC 7.4.1):
$ cabal install unroll-ghc-plugin
File bugs in the GitHub issue tracker.
Master git repository:
git clone https://github.com/thoughtpolice/unroll-ghc-plugin.git
There's also a BitBucket mirror:
git clone https://bitbucket.org/thoughtpolice/unroll-ghc-plugin.git
LICENSE.txt for terms of copyright and redistribution.