I've ported some code from C to C++ and I'm shocked at how much more slowly it runs. I've written a lot of C++ in the past, so I know I haven't done anything absurdly inefficient, but execution times have gone up by 150% (2.5 times slower!). Has anyone else seen anything like this? Are there any particular aspects of the Keil C++ implementation that I should look out for?
I'm working on some library code which is shared between several application. The plan is for the library to contain some generic implementations for general use, and each application can (if necessary) subclass a derivative which uses application specific optimisations.
Optimisations based on the application can be an order of magnitude (or more) faster than the generic implementations because they can eliminate unnecessary flexibility and they can bring additional resources to bear.