Re: [patch] combined build

[Dmitry Antipov]

Richard Stallman wrote:

> We should add this if it provides substantial benefit, but otherwise
> let's not.

For now, size benefits are marginal - ~11k if compiled with -O2 and
~7k if compiled with -Os.

It's not so easy to measure speed of interactive application, but
the speed of byte-compilation looks exactly the same (up to the
errors of measurement).

The worst news is that I was unable to compile both with '-combine'
and '-fwhole-program' - temacs just crashes silently with huge core,
which probably means C stack overflow due to deep recursion.
This applies to both 4.2.1 and 4.2.2 versions of GCC. I'm trying
to understand why this happens, but still have no ideas.

So, it looks like this technology doesn't give substantial benefits
for today. But I believe it's features should be revised periodically,
according to the state and progress of GCC development.

Dmitry