On Sat, Sep 27, 2008 at 4:20 PM, Marc Feeley <[EMAIL PROTECTED]> wrote: > Hi Felix. I did not mean to drag you into this discussion. I know > performance benchmarking is one of your buttons that is best left untouched!
I'm happy to have taken my little part in it. > > All of this started with this message on the Gambit mailing list about the > performance claim that call/cc in Chicken was "free" because of Cheney on > the MTA and that Gambit used the same approach: > > On 24-Sep-08, at 11:14 AM, Per Eckerdal wrote: > >>> Chicken. Cheney on the MTA gives you call/cc essentially >>> for free - it's just as fast as any other function call. >> >> I was under the impression that Gambit also did this.. Am I wrong? >> >> /Per > > My response was that Gambit's continuations are based on a completely > different approach which gives just as good performance, using the ctak and > fibc benchmarks as simple evidence. A complete analysis of the two > approaches would take a lot of effort, which is why I used these benchmarks > as a quick-and-dirty way to evaluate the performance (it turns out that ctak > is much better than fibc as a benchmark for call/cc because fibc does many > other things than just call/cc, i.e. it measures other optimizations of the > compiler). Right, but aren't all benchmarks just quick-and-dirty? (hopefully quick, of course). Note that in chicken the continuations that the Scheme programmer sees are not the real ones: they are wrapped in a closure and must perform extra work checking dynamic-wind thunks. There are some internal procedures (##sys#call-with-direct-continuation and ##sys#direct-return) which are really cost-free, as they use directly the implicit continuations that are created in the compilation processs. > > Let me reiterate that I'm not trying to compare Gambit and Chicken as > systems. If that was the case I would have much more to say and obviously > would conclude that Gambit is better ;-) Of course. cheers, felix _______________________________________________ Chicken-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/chicken-users
