It was too late... Thanks a lot for your examples of measureing. I will try it a little bit more. --daishi
At Thu, 06 Oct 2005 01:29:08 -0500, Alex Shinn wrote: > You have to be careful what you're measuring. Inside the loop you > repeatedly call expt, which is slower not only because it makes many > more checks than before, such as checking the types and signs of the > arguments, but because it checks the fixnum case last. > > If you bind the result once outside the loop you'll see the time using > fx+ (and also fx> to be sure we're comparing the same thing) is indeed > exactly the same: > > $ csi -eval '(let ((2^17 (expt 2 17)))(gc)(time (let loop ([i 0]) (or (fx> i > 2^17) (loop (fx+ i 1))))))' > 0.313 seconds elapsed > 0 seconds in (major) GC > 31 mutations > 1285 minor GCs > 0 major GCs > > $ csi -R numbers -eval '(let ((2^17 (expt 2 17)))(gc)(time (let loop ([i 0]) > (or (fx> i 2^17) (loop (fx+ i 1))))))' > 0.313 seconds elapsed > 0 seconds in (major) GC > 31 mutations > 1285 minor GCs > 0 major GCs > > Now let's compare the time of the generic numbers + and normal +: > > $ csi -eval '(let ((2^17 (expt 2 17)))(gc)(time (let loop ([i 0]) (or (> i > 2^17) (loop (+ i 1))))))' > 0.325 seconds elapsed > 0 seconds in (major) GC > 31 mutations > 1289 minor GCs > 0 major GCs > > $ csi -R numbers -eval '(let ((2^17 (expt 2 17)))(gc)(time (let loop ([i 0]) > (or (> i 2^17) (loop (+ i 1))))))' > 0.454 seconds elapsed > 0.002 seconds in (major) GC > 31 mutations > 58 minor GCs > 1 major GCs > > 0.454 vs 0.325, or about 1.4x slower when using the full number tower. > > -- > Alex _______________________________________________ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
