Looks like a reasonable benchmark of this. Nice work. There's definitely a lot of room for improvement of dynamic dispatch. We can't use classic vtables because of the multiple part of Julia's dispatch – where do you stick the vtable? Most of the time we get performance by avoiding dispatch entirely, by pushing the dispatch up as far as possible, but there are cases like what you've create here, where that doesn't work.
On Fri, Nov 6, 2015 at 12:27 PM, Cristóvão Duarte Sousa <[email protected]> wrote: > Hi, > > I've been wondering how Julia dispatching system would compare to the C++ > virtual functions dispatch one. > Hence, I write a simple test in both Julia and C++ that measures the > calling of a function over the elements of both an array of concrete > objects and another of abstract pointers to objects of derived types. > > Here is the code https://gist.github.com/cdsousa/f5d669fe3fba7cf848d8 . > > The usual timings for C++ in my machine, for the concrete and the abstract > arrays respectively, are around > 0.000143 seconds > 0.000725 seconds > > For the Julia code the timings have much more variability, but they are > around > 0.000133 seconds > 0.002414 seconds > > This shows that Julia (single) dispatch performance is not that bad while > it has some room to improvement. > > If I'm doing something terribly wrong in these tests, please tell me :) > > PS: Thank you all, developers of Julia! > > >
