Re: configure speedup proposal: add --assume-c99 and --assume-posix2008 flags

[Rhys Ulerich]

On Fri, Jun 6, 2014 at 9:48 AM, Paul Eggert <address@hidden> wrote:
> veerrry common for 'configure' to be an unreasonably large part of the build
> process

But is an unreasonably large part of a reasonably long build process?
You quote a from-scratch build with configure being an order of
magnitude slower than parallel compilation.  But one just 35 seconds
long.

Granted, configure time does add up if one builds 10s of packages in
sequence.  Is there some reason configure caches are unsuitable to
gain speedup there?  I see almost a six-fold configure improvement on
grep-2.20 when its working from a config.cache.  That brings configure
to 140% of parallel compilation, but we're talking an overall build
like 6 seconds.

- Rhys