[desktop-discuss] [xwin-discuss] libtool performace improvements ... / was: Re: [Fwd: Announcing Dolt, a drop-in Libtool replacement which cuts build times in half]

[Moinak Ghosh]

Bob Friesenhahn wrote:
> On Thu, 10 Apr 2008, Moinak Ghosh wrote:
>>
>>  One other optimization that I was considering was to use
>>  pre-generated config.cache files. For eg. in the drivers
>>  subdirectory the config.cache generated for the first driver
>>  built is copied to a common location and then that is passed as a
>>  parameter while calling configure for the rest of the drivers. This
>>  avoids a whole plethora of redundant checks the results of which
>>  are already in the cache.
>
> This works if the build options are the same for all builds and the 
> configure scripts make the same decisions based on the same 
> information.  That is not always the case.

   True. But for FOX at least the configure options for individual modules
   in a given sub-directory are mostly same.

>
> Another choice is to create a config.site file or a file referenced by 
> the CONFIG_SITE environment variable which includes a 
> carefully-crafted set of pre-known cached settings which are safe for 
> all drivers.
>
> Yet another choice is to have a single config.h shared across all 
> drivers and a mega configure script which tests everything the drivers 
> need, or have the drivers test only special things that they need and 
> have them include the mega config.h as well as their own config.h.
>
> As far as the libtool performance issue goes, the issue is being taken 
> very seriously right now and libtool will certainly become faster. One 
> important suggestion (that bash is very slow) came from this list.
>
> Libtool 2.2 (current release) is already 60% faster than Libtool 1.5.X.

   Yet another piece, unrelated to libtool is to parallelize FOX builds.
   Right now it is completely serial.

Regards,
Moinak.

>
> Bob
> ======================================
> Bob Friesenhahn
> bfriesen at simple.dallas.tx.us, 
> http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
>