[Libreoffice] gnumake / dependencies 20%+ speedup ...

[Bjoern Michaelsen]

Hi Michael,

On Mon, 05 Sep 2011 12:38:56 +0100
Michael Meeks <michael.meeks at novell.com>
wrote:

> 	So - we need these rules in place; with a small tweak to my
> script to print the dummy rules we'd be throwing away, I notice that
> we have (eg.) [...]
> 	several hundred duplicate dummy rules for many headers - still
> consuming big chunks of the aggregated library dependency files. That
> yields 441k redundant lines instead of 445k - but I think that's most
> of the win ;-)

Yes, that is most likely because we generate the deps for each object,
but cat them together for each linktarget to reduce file-io later.
Instead of cat'ing the objects we could indeed pipe them trough some
cleanup script.

> 	I attach an updated cleanup.pl - that leaves the dummy rules,
> but removes duplicates in them; it takes a second or two to run
> itself ;-) [ we could write it in C no doubt to accelerate it if that
> is an issue ]. Which gmake rule builds the aggregated library
> dependency file that could have this wedged into it ?
Looking good from this perlhaters point of view. I would have written
it in awk for performance and lean-dependency reasons, but I am not
too zealous about that. To inject it to the build system, add it in
around here:

http://opengrok.libreoffice.org/xref/core/solenv/gbuild/LinkTarget.mk#401

Best,

Bjoern

-- 
https://launchpad.net/~bjoern-michaelsen