problems using ghc-6.6.1

Christian Maeder maeder at
Wed May 9 05:21:14 EDT 2007

Simon Marlow schrieb:
> Christian Maeder wrote:
>> Dear Hets- and GHC-Developers,
>> we have a problem using ghc-6.6.1. The created hets binary runs a couple
>> of times slower than the one created using ghc-6.6. (see below)
>> What might be the cause for this?
> Very strange.  The performance has decreased dramatically, but the
> profile looks the same: that is, performance has degraded more or less
> consistently across the whole code.  I have to ask: did you turn on -O?

-O was turned off in both cases. (Optimization usually only accounts for
a factor of 3 -- and not 8 or even more.)

Sorry for my panic. The slow down is caused by the last change described in

The additional loops in Data.Graph.Inductive.Graph (also added at the
end of a possibly long list) make our algorithm slower.

context1l' :: Context a b -> Adj b
context1l' (p,v,_,s) = p++filter ((==v).snd) s

context4l' :: Context a b -> Adj b
context4l' (p,v,_,s) = s++filter ((==v).snd) p

Cheers Christian

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