Jan Hubicka wrote: > One problem that I am concerned about is that C++ frontend is actually > trying to avoid instantiating some stuff that it knows will not be > needed if not inlined. I would kill this logic, but I hope this is the > case where the feature is not worth the maintenance cost.
We need to be careful about terms. "Instantiating" means "substituting actual arguments into a template definition to get an actual definition". There's also generating definitions for implicitly-declared class member functions; that doesn't have a great term in the standard, but we can call it "defining implicit functions". Which one of these situations are you concerned about? I guess, in a way, it doesn't matter which one. In both cases, the standard says when you must do it. So, we can't change that. I suspect that the code that you're looking at may have just been a front-end optimization. For example, at least at one point, it made GCC a lot slower to have very long instantiation chains: f needs g<int>, g<int> needs h<int>, etc. It was better to instantiate things one at a time than to have a deep stack. But, if h<int> was inline, then we needed to make sure its body was available when g<int> was being instantiated so that we could inline it. Now, that's probably no longer true. We can probably always avoid the deep stack, and just let cgraph handle it. -- Mark Mitchell CodeSourcery [EMAIL PROTECTED] (650) 331-3385 x713
