Profiling compilation time
Yang Zhang
yanghatespam@gmail.com
Wed Mar 25 06:06:00 GMT 2009
Ian Lance Taylor wrote:
> In my experience, when not optimizing, C++ compilation time is normally
> dominated by parsing and name lookup.
From an earlier thread "Precompiled headers and templates:"
Ian Lance Taylor wrote:
> However, including explicit instantiations in the precompiled header
> won't make any significant difference to compilation time. The
> precompiled header saves on parsing and name lookup time, it doesn't
> save on code generation time.
>
> I don't personally find that precompiled headers help with compilation
> time all that much. However, for some projects, ones with millions of
> lines of header files included in every compilation, I expect that they
> would help.
So PCHs only help with a very small fraction of the parsing + name
lookup? (Already established that they wouldn't include template
instantiation component of paths.)
--
Yang Zhang
http://www.mit.edu/~y_z/
More information about the Gcc-help
mailing list