bug#311: Interesting results

Seth David Schoen writes:

> I ran a build of fs/e2fsprogs with the normal gar.conf.mk, and then I
> ran it again with a modified gar.conf.mk in which CFLAGS had "-Os" at
> the end.
> 
> What I found was that some binaries came out smaller, and other
> binaries came out larger!
> 
> e2fsprogs has a default of -O2, and so the -Os is overriding that.
> That implies that -O2 sometimes produces smaller binaries and
> sometimes produces larger binaries than -Os, even though really it
> should never produce larger binaries.  I think this is a gcc bug.
> 
> A little later, I'm going to run a full build with -Os and see what
> the net effect on the size of the image is.  Nick used to have a -Os
> in there somewhere, and I don't remember why or when he took it out.

The answer is that -- building on garson outside the chroot, using
Nate's new gar -- the images built with -Os are more than 1,200,000
bytes smaller than images built without -Os.  (OK, I also changed
hackedbox slightly in that tree in between, but I think that was almost
insignificant.)

I think Nick might have been the only person building with -Os,
because, as I mentioned, it's not documented anywhere.

We could put a -Os in gar.conf.mk (which is what I did for this
build).  The only downside is that some other gar-built distributions
might not want it.  Could we put it in meta/lnx-bbc?

Some packages still don't use CFLAGS at all.  By forcing more packages
to honor our CFLAGS, we can reduce the size of the image even further.

-- 
Seth David Schoen <[email protected]> | Reading is a right, not a feature!
     http://www.loyalty.org/~schoen/   |                 -- Kathryn Myronuk
     http://vitanuova.loyalty.org/     |