I've written down some thoughts on the current status and future direction of the LLVM backend here [1]. Have a look when you get a chance. To summarize, * it seems like LLVM 3.4 chokes on the code produced by my 3.5 rework when the `$def` symbols are marked as internal * ARM is broken (again) due to a bug in the GHC calling convention implementation; an LLVM fix is waiting to be merged * I have code reworking TNTC for LLVM 3.6; unfortunately LLVM 3.6 support will likely need to wait until 7.12 * Austin's LLVM packaging proposal seems very much like the right way forward * Anticipating this proposal, I have started collecting [2] optimization passes Cheers, - Ben [1]: http://smart-cactus.org/~ben/posts/2014-11-28-state-of-llvm-backend.html [2]: https://github.com/bgamari/ghc-llvm-analyses