Re: Compilation time (was Re: GCC 3.3)

[Matt Austern <austern at apple dot com>]

On Wednesday, April 30, 2003, at 01:18 PM, Paul Koning wrote:

> > > > > > "Diego" == Diego Novillo <dnovillo@redhat.com> writes:
>
>  Diego> On Wed, 2003-04-30 at 14:28, Phil Edwards wrote:
> > > Somewhat re-ording your suggestions.
> > >
> > >
> > > On Tue, Apr 29, 2003 at 05:30:22PM -0700, Matt Austern wrote: >
> > > 1. Compile an unchanging piece of source code.
> > >
> > > Anything in particular?  I don't much care what, but its build
> > > time multiplied by 5 needs to not be hellishly long.  (The machine
> > > is used for other things; and of course is can't be doing any of
> > > those other things while these tests are running.)
>  Diego> I collected a bunch of .i files from the C front end and use
>  Diego> that as my unchanging code base.  It shouldn't take long to
>  Diego> compile this 2-3 times to get a good average.
>
> I think you need to start from c or c++ files, because that's the real
> world scenario and that's what matters to people who are using gcc.

I agree.  We've found that in some cases preprocessor time can be 
significant.  We've also found that the sum of preprocessing time and 
time to compile a .ii file is greater than the time to compile the .cc 
file to begin with.

			--Matt