Faster Compliations - PCH support?

[Neil Booth]

Andrew Pinski wrote:-

> Read the archives, there are a few different PCH support for gcc 
> and one or a combination might be added to gcc.
> 
> Also it is not the preprocessing that takes a long time but the 
> parsing that takes the longest time on c++.
> So it might be faster to change the parsing code which is 
> ongoing, look at the cp-parse branch.

I think you misunderstand the scope of PCH.  PCH does a lot more
than preprocessing; it tends to combine all of preprocessing,
parsing, decl creation, type layout, semantic checks and possibly
even more into one.  Ideally it would represent all compiler state
up to the point where the main file's real code begins.

Neil.