-optc-O2 considered useful

[Neil Mitchell]

Hi

> As for the specific issue of whether we should turn on -fstrictness with
> -O0, I suspect the answer is that the compile-time cost would be too high.

There would also be the issue that it would increase the amount of
Haskell code which works only in GHC, which is probably a bad thing.
Would the strictness still recover the loop if they turned on
hpc/profiling? I can see many reasons why making things faster is
good, but making things asymptotically faster/less space in -O0 could
bite later.

One ticket that probably makes a big difference in -O0 is:
http://hackage.haskell.org/trac/ghc/ticket/2207

Thanks

Neil