Don't target OCaml. It's a fine language but a shitty backend. You'll get saddled with a wonky 31/63 bit integer type and a very literal non-optimizing compiler

Don't target OCaml. It's a fine language but a shitty backend. You'll get saddled with a wonky 31/63 bit integer type and a very literal non-optimizing compiler. Similarly, compiling to Haskell may result in unpredictable performance due to unintentional laziness (though I guess you could stick strictness annotations everywhere). I would go with LLVM-- they give you an IR which is reasonably high level and comes with a whole armada of analyses and optimizations.