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Re: Loop unrolling-related SPEC regressions?
> Jan Hubicka <firstname.lastname@example.org> writes:
> > I am playing with the idea of making -O behaving like -f and allowing -Ospeed
> > "optimize for maximal speed for common circmuatens" and -Osize. We can also
> > invent -O[no]debug "prohibit optimizations that make debugging dificult, like
> > tail call optimization, frame pointer ellimination, or (currently) register
> > renaming",
> Don't we already have these? -O3 is what you call 'Ospeed', -Os is
> what you call 'Osize', '-O0' is Odebug.
Yes and no. Defnitly to get best perofrmance you don't need to enable
just -march=mymodel -O3
We disable some options at higher optimizations levels just to allow debugging
(like -fomit-frame-pointer, register renaming, loop unrolling).
It is somewhat dificult to orientate in the optimization levels for users
and I am not sure what exactly can we do with the situation.
> - Geoffrey Keating <email@example.com> <firstname.lastname@example.org>