[Haskell-cafe] Performance Help

[Neil Mitchell]

Hi

> I notice that there's not much user-accessible documentation of what you
> can expect GHC (or some other Haskell implementation) to do and not do
> with a given piece of code.

Yhc/nhc/Hugs - nothing

GHC - inlining, simplification, fusion if you use the build in
functions in a specified way, strictness analysis, maybe some
unboxing, let movement, some other tricks

JHC - everything

The problem is that things like strictness are a static analysis which
is undecidable in general. Static analysis is probably too complex for
the user to figure out what is going on, its much better to look at
the Core generated and see what actually happened.

Thanks

Neil