C compile time

[Jan Hubicka]

> 
> > Note that I consider not having unit-at-a-time for C++ for 3.4 as a
> > showstopper as it is possibly the only way to get sane inlining and
> > such sane performance out of scientific C++ codes like POOMA.
> 
> I don't think that this is a particularly true statement. C++ codes have many 
> member functions that can be called from everywhere, and few file-static 
> functions. So being able to inline static functions that are only called once 
> is not a very important feature. The general ability to inline small accessor 
> and template functions is much more important, but that is independent of 
> unit-at-a-time.
Actually there are so few static functions in C++ so unit-at-a-time as
implemented currently has almost no effect.  On the other hand if we
reorganize inlining heuristics to take into acount code growth inlining
function X causes, I think we will get easy win for the inlining
problems in C++...  This is also dificult to do without an callgraph.

Honza
> 
> W.
> 
> -------------------------------------------------------------------------
> Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
>                                www: http://www.ices.utexas.edu/~bangerth/
>