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Re: Final intermodule patch
> > Date: Mon, 14 Jul 2003 11:07:51 +0100
> > From: Nathan Sidwell <nathan@codesourcery.com>
>
> > Geoff,
> > I think the command line option handling for the (excellent) intermodule
> > mode is wrong.
> >
> > gcc -c file1.c file2.c
> > gets me separate file1.o and file2.o objects.
> > gcc -c file1.c file2.c -o foo.o
> > gets me intermodule work. Yet I've not changed any *optimization*
> > option.
>
> Right. My patch does not implement any optimisations, and it is not a
> change to the optimizers. You do not get better code generation just
> because you use it; you must use -Osomething too.
Still I found this quite contraintuitive too, as I wasn't able to figure
out how to get the intermodule optimization without looking into how gcc
Makefile works with --enable-intermodule.
There is no even this word mentioned somewhere in the manual.
I am not quite sure how to improve current situation given that we can't
save any "modules" to imitate normal compilation process as most of
other IPA optimizers do for political reason, but at least better
documentation is definitely needed.
With -O2 -funit-at-a-time and mlutiple source files you now get (simple)
intraprocedural optimization so it should be documented so.
Honza