Removing/deprecating -fvia-c

[Don Stewart]

davidterei:
>
> I've been looking at some of these cases and seeing how the LLVM  
> back-end performs. My general impression from benchmarking the LLVM  
> back-end in the past has been that it generally performs with similar  
> characteristics as the C code generator (that is, where the C code  
> generator stood out compared to the NCG, so did LLVM).
>
> (On x86-32/Mac OS X 10.5, had some issues getting x64 working at moment):
>
> ./zipWith3_viac  0.72s
> ./zipWith3_fasm  0.65s
> ./zipWith3_llvm  0.38s

Those are great numbers!

I've added llvm support to ghc-core (if you compile with -fllvm,
ghc-core will display the core and assembly in the pager, syntax
highlighted).

Unfortunately, llvm.org is down, so I can't apply patches to my llvm
install at the moment, but I have managed to compile a fair few things
on x86_64 -- they don't run though :-)

What's the status of the x86_64 llvm backend, do you know, and are there 
ways to tune the optimizations that llvm applies?

Should we just be using the llvm binding package on Hackage? 

-- Do