[racket-dev] [plt] Push #20559: master branch updated

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Thu Jun 24 14:18:28 EDT 2010

Thanks for running more timiggs. One last question: your timing tests
were in a module, not the toplevel, right?

Robby

On Thursday, June 24, 2010, Eli Barzilay <eli at barzilay.org> wrote:
> On Jun 23, Sam Tobin-Hochstadt wrote:
>>
>> Do we really want to remove contracts from code just because they
>> don't perform as well as hand-written checks?
>
> The code in question is about 15 lines; at least I expect such code to
> run fast enough so I'll use it instead of writing my own 15 lines; the
> difference is huge (2.5 factor).
>
>
>> Also, did you try just changing the result contract from `void?' to
>> `any/c'?
>
> Did you?
>
>
> On Jun 24, Robby Findler wrote:
>> A factor of 4 for removing those contracts and turning them into
>> checks seems suspicious. They should not be that bad. Possibly Eli
>> made other changes in there too?
>
> The 4x factor is overall, mostly due to turning it from a
> double-linked list to single links.  The contracts factor is still
> very high: about 2.5x.  Specifically:
>
> No contracts (current version):
>   cpu time: 10341 real time: 10344 gc time: 5156
>
> Original contracts (and I removed the checks from the code):
>   cpu time: 26205 real time: 26207 gc time: 7382
>
> Same contracts but using any/c:
>   cpu time: 25862 real time: 25865 gc time: 7338
>
> Using queue/c instead of nonempty-queue/c (add a runtime check instead):
>   cpu time: 24978 real time: 24981 gc time: 7157
>
> Using the struct predicate directly instead of flat-named-contract:
>   cpu time: 24838 real time: 24841 gc time: 7131
>
> --
>           ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
>                     http://barzilay.org/                   Maze is Life!
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