Update to llvm-hs(-pure) 5.1

[OndrejSlamecka]

• 825c8fb prevents llvm-hs from stopping with an error about instructions returning void (e.g., store) having a name,
• cc60b61 provides a function for easily getting pointers to inside-llvm-functions in the front end.

The following code (to be put in src/Main.hs) is an example where the commits help. If e.g., double was used instead of the function pointer then llvm-hs would stop with an error, see sdiehl/kaleidoscope#45.

logic :: LLVM ()
logic = do
  define double "foo" [(double, "a")] $ do
    ret (local double (AST.mkName "a"))

  fooPtr <- fnPtr (AST.mkName "foo")

  define double "main" [] $ do
    let a = cons $ C.Float (F.Double 10)
    let b = cons $ C.Float (F.Double 20)

    a' <- call (externf fooPtr (AST.mkName "foo")) [a]

    c <- alloca double
    store c b
    c' <- load c
    res <- fadd a' c'

    ret res

The corresponding PR for the tutorial is sdiehl/kaleidoscope#46.

[sdiehl]

Looks great, thanks!

[sdiehl]

I think at some point I'm going to rewrite the tutorial to just the IRBuilder itself, rather than reimplementing it inside the tutorial.

[OndrejSlamecka]

Happy I could help. If I understand it correctly, there's not much of a point in porting this to the tutorial at the moment, so I have closed sdiehl/kaleidoscope#46 Maybe, for the time being, we could put a link to this repository to the beginning of the tutorial so that people with LLVM 5 can find a working code easily.

[sdiehl]

Indeed, I'll update the text to link here.