[Haskell-cafe] GHC optimisations

[Hugh Perkins]

On 8/22/07, Twan van Laarhoven <twanvl at gmail.com> wrote:
> But Double is already quite badly behaved:
>  > let x = 1e20
>  > Prelude> 1 + (x - x)
>  > 1.0
>  > Prelude> (1 + x) - x
>  > 0.0

Ewwww.  Whilst that's understandable and unavoidable, that kindof
rings alarm bells for folds of Doubles in an automatic threading
situation.  Ie, if we split our fold between 4 cores, we might get a
different answer than if we split it between 8 cores?