Christopher Wright: > > Certainly agreed on virtual calls: on my machine, I timed a simple > > example as executing 65 interface calls per microsecond, 85 virtual > > calls per microsecond, and 210 non-member function calls per > > microsecond. So you should almost never worry about the cost of > > interface calls since they're so cheap, but they are 3.5 times slower > > than non-member functions.
The main problem of virtual calls in D are the missed inlining opportunities. ------------ Andrei Alexandrescu: > I seem to recall that > interface dispach in D does a linear search in the interfaces list, so > you may want to repeat your tests with a variable number of interfaces, > and a variable position of the interface being used. The following is a D port of the well known "Richards" benchmark. This specific version is object oriented, its classes are final (otherwise the code gets quite slower with LDC) and it has getters/setters. It contains an interface: http://codepad.org/kO3MJK60 You can run it at the command line giving it 10000000. On a Celeron 2 GHz if you replace the interface with an abstract class the running time goes from 2.16 to 1.58 seconds, compiled with: ldc -O5 -release -inline Compiled with DMD the running time seems about unchanged. I have no idea why. Maybe some of you can tell me. In a day or two I'll release many more timings and tests about this Richards benchmark. Bye, bearophile
