[Haskell-cafe] Re: speed: ghc vs gcc

Bulat Ziganshin bulat.ziganshin at gmail.com
Fri Feb 20 10:44:36 EST 2009

Hello Peter,

Friday, February 20, 2009, 6:34:04 PM, you wrote:

> Well C# does it with a for loop in 2300ms, and when using a
> IEnumerable sequence it needs 19936ms. Very much like the Haskell
> code. But of course the Haskell code could optimize the sum I guess,
> I assume it is using the lazy version of sum by default.

the question is what is the natural for every language

> Anyway it was more of a question. Does GHC perform register
> allocation (e.g. using graph colouring)  and loop unrolling?

afaik, ghc can be compared with 20-years old C compilers. it uses
registers for performing tight loops but has very simple register
allocation procedure. also it doesn't unroll loops

> On Fri, Feb 20, 2009 at 4:22 PM, Colin Paul Adams <colin at colina.demon.co.uk> wrote:
>>>>>> "Peter" == Peter Verswyvelen <bugfact at gmail.com> writes:
>     Peter> So GHC is about 3 to 4 times slower as Visual C++ / GCC
>     Peter> without loop unrolling, which is not too bad since GHC does
>     Peter> not perform register optimization and loop unrolling yet
>     Peter> no?
>  I would call it rather poor.
>  And I don't accept a since of that form as valid mitigation.
>  --
>  Colin Adams
>  Preston Lancashire


Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com

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