It may help to turn dmd's optimizer and inliner on - "dmd -inline -release -O -boundscheck=off".
On Sun, Aug 28, 2016 at 5:43 AM, Matthias Redies via phobos <phobos@puremagic.com> wrote: > Hello, > > I've come across the library experimental.ndslice, which is supposed to > mimic NumPy. In order to test it I wrote a very crude matrix multiplication: > > http://pastebin.com/Ew4u2iVz > > and for comparison I also implemented it in Fortran90: > > http://pastebin.com/6afnVyZF > > Then I used linux's "time" command to time them each: > > ifort test.f90 && time ./a.out > 600 > > real 0m0.154s > user 0m0.148s > sys 0m0.004s > > > dmd test.d && time ./test > 1.16681e+08 > 600 600 > > real 0m6.770s > user 0m6.772s > sys 0m0.004s > > > I understand that dmd is not optimized for speed, but in the end both do > basically the same thing. Both implement 2D array and both array types > include the size of the array (unlike C). Given that both are compiled > languages the difference seems to be unreasonably large. > > If I turn on boundschecking for Fortran I get: > > ifort -check all test.f90 && time ./a.out > 600 > > real 0m6.049s > user 0m6.044s > sys 0m0.004s > > > which is roughly the speed difference I'd expect, but if I use the > -boundscheck=off option for dmd that doesn't help. Am I using ndslice > correctly? Why is the speed difference so large? How do I speed it up? > > Kind regards > > Matthias > > _______________________________________________ > phobos mailing list > phobos@puremagic.com > http://lists.puremagic.com/mailman/listinfo/phobos _______________________________________________ phobos mailing list phobos@puremagic.com http://lists.puremagic.com/mailman/listinfo/phobos
