Faster, GHC, and floating point.

Andreas.Schroeder at gillardon.de Andreas.Schroeder at gillardon.de
Tue Oct 21 14:01:14 EDT 2003


Well, i found the reason why it did work with haskell and not with C.
It was simply that for haskell i provided an arch via -optc-march=pentium3
and did not the same with
C++ (... i should have read the sse option documentation).

Thanks for the hint about strictness on large data structures.

Regards,
Andreas



|---------+--------------------------->
|         |           Michael Weber   |
|         |           <michaelw at foldr.|
|         |           org>            |
|         |                           |
|         |           21.10.2003 12:55|
|         |                           |
|---------+--------------------------->
  >-------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                   |
  |        An:      Andreas.Schroeder at gillardon.de                                                                    |
  |        Kopie:                                                                                                     |
  |        Thema:   Re: Faster, GHC, and floating point.                                                              |
  >-------------------------------------------------------------------------------------------------------------------|



On Tue, Oct 21, 2003 at 12:03:34PM +0200, Andreas.Schroeder at gillardon.de
wrote:
>
> Can't tell you, SSE is disabled by cygwin when i try -mfpmath=sse i get
the
> message

If you compare one language with SSE enabled and another one without, this
is like comparing apples and oranges, no?  It's rather meaningless when
trying to decide how good Haskell performs compared to C++.  And I have no
doubt your C++ colleagues will point you to it... ;)


> Oh, and btw, using MinGW yields the same message for C/C++.
> For haskell actually, it _makes_ a difference. Don't ask me why and how.

It would be good to find out what is going on there before comparing
values.


BTW: my personal experience is that with bigger datastructure it gets worse
for Haskell rather than better.  Closures and copying add a lot of overhead
and you really have to keep on eye on strictness.


Cheers,
Michael







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