#3245: Quadratic slowdown in Data.Typeable
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Reporter: guest | Owner:
Type: run-time performance bug | Status: new
Priority: normal | Milestone:
Component: libraries (other) | Version: 6.10.1
Severity: major | Resolution:
Keywords: | Testcase:
Os: Linux | Architecture: x86
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Comment (by guest):
As demonstration that the slowness in the cast is from the typeOf call see
the attached {{{TypeOfSpeed.hs}}}.
Example run:
{{{
$ ghc --make -O3 TypeOfSpeed.hs
[1 of 1] Compiling Main ( TypeOfSpeed.hs, TypeOfSpeed.o )
Linking TypeOfSpeed ...
$ ./TypeOfSpeed 20000
count1
Result: 20000
Time(sec): 9.998e-3
Result: 20000
Time(sec): 2.0e-3
Result: 20000
Time(sec): 2.0e-3
count2
Result: 20000
Time(sec): 1.455779
Result: 20000
Time(sec): 1.414784
Result: 20000
Time(sec): 1.415785
}}}
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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3245#comment:2>
GHC <http://www.haskell.org/ghc/>
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