Optimization beyond the Module Border

[Bernd Brassel]

Simon Peyton-Jones wrote:

> GHC does a lot of cross-module inlining already, and *does* write stuff into interface files, provided you use -O.

I used -O4. Is that the bad thing?

> I'm always interested in performance differences of a factor of 15 though!  Can you supply an example (as small as poss) for us to look at?

Yes certainly, although small will be a big problem, I guess.
I admit that the factor 15 is a bit dubious since the fast run-time was
so small (1.88 sec vs. 0.112 sec).

I will see what I can do on the morrow.