[Haskell] inline assembly a la gcc

Is there a way in which I can interface GHC with assembly language ? Of course I can create a stub C function which using inline assembly, compile it with GCC, and crankin the FFI of GHC. But is there a more direct way ? I would like to try coding, (or steal from some open source implementation) up some crypto hash functions in assembly and compare it with a direct GHC implementation. I will be happy if there is a way of avoiding assembly all together and work with GHC internals like Int# etc. which gives me almost assembly speed. Regards ppk