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

[Louis Wasserman]

Sebastian, that's not Bulat's point.  He's saying that if we make that
optimization in Haskell, we should at least make the same optimization in
GCC for fair comparison.  (Though I'm not entirely sure that that
optimization would be of any use to GCC, but that's a linguistic concern, no
more.)

His point is valid.  But Don's results *not* obtained by optimizing in this
fashion are valid comparisons, and the results obtained with this
optimization are useful for other reasons.

Louis Wasserman
wasserman.louis at gmail.com


On Sat, Feb 21, 2009 at 5:55 PM, Sebastian Sylvan <
sylvan at student.chalmers.se> wrote:

>
>
> On Sat, Feb 21, 2009 at 11:35 PM, Bulat Ziganshin <
> bulat.ziganshin at gmail.com> wrote:
>
>> Hello Louis,
>>
>> Sunday, February 22, 2009, 2:30:23 AM, you wrote:
>>
>> yes, you are right. Don also compared results of 64x-reduced
>> computation with full one. are you think that these results are more
>> fair?
>>
>
> Yes. Clearly so.
> It still computes the result from scratch - it just uses a trick which
> generates better code. This is clearly a useful and worthwhile exercise as
> it shows A) A neat trick with TH, B) A reasonably practical way to produce
> fast code for the critical parts of a Haskell app, C) a motivating example
> for implementing a compiler optimization to do it automatically.
>
> Just outputting the precomputed result means nothing.
>
>
>
> --
> Sebastian Sylvan
> +44(0)7857-300802
> UIN: 44640862
>
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