[Haskell-cafe] Interesting effect of upgrading GHC

Ketil Malde ketil+haskell at ii.uib.no
Tue Nov 13 04:02:47 EST 2007

"Neil Mitchell" <ndmitchell at gmail.com> writes:

>> I just removed GHC 6.6.1 and installed 6.8.1, and I noticed something
>> rather unexpected. I recompiled an existing program (with -O2), and
>> instead of taking 30 seconds to compile, it took roughly 2 seconds.

> In previous releases, certain constructs took O(n^2) time to compile.
> One that was a particular issue for me was:

I've noticed that largish data structures - in my case, ~20x20
matrices - embedded in code seems to take a surprisingly long time to
compile. (I haven't noticed (nor looked for) any speedup with new
releases, though.) 

If I haven't seen further, it is by standing in the footprints of giants

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