[Haskell-cafe] Re: MD5 performance optimizations, and GHC -via-C producing segfaulting binary

[Isaac Dupree]

Don Stewart wrote:
> I'm confused. GHC of course unboxes strict fields of primitive data types.
> 
>     {-# OPTIONS -O2 -fvia-C -optc-O2 -funbox-strict-fields #-}

... but only when you give -funbox-strict-fields, as there, or UNPACK. 
The point is that it never loses sharing to unbox a strict Int field 
[1], so it should do that with -O, even without either of the above 
overrides.

[1] I'm not sure if this is true... if it has to rebox the Int, you get 
another copy floating around, not the original, right?

-Isaac