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From: Pascal Obry <p.obry@wanadoo.fr>
Newsgroups: comp.lang.ada
Subject: Re: What is faster Ada or C?
Date: 02 Dec 2001 11:44:08 +0100
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Jeffrey Carter <jrcarter@acm.org> writes:

> Heiko Hamann wrote:
> > 
> > Well, _any_ difference? Hey, this is unbelievable! The difference between
> > the program compiled with
> > standard options and the program compiled with -gnatp and -O3 is terrific.
> > The acceleration is about 70%! The new compilation needs only about 1/4 of
> > time the old one needed. I can't believe it.
> > The new program is about 1/5 smaller than the old one.
> 
> Most of this difference is probably due to optimization. GNAT produces
> very poor code with no optimization. Even -O1 often makes a significant

Indeed. The -O0 (default option) of GCC/GNAT is doing just no optimization at
all. It even does not try to be smart :)

The first "real" optimization steps for GCC/GNAT is done at -02.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
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--| "The best way to travel is by means of imagination"