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Date: Fri, 24 May 2002 18:44:02 +0100
From: Christoph Hellwig <hch@infradead.org>
To: Robert Love <rml@tech9.net>
Cc: Marcus Meissner <mm@ns.caldera.de>, linux-kernel@vger.kernel.org
Subject: Re: Compiling 2.2.19 with -O3 flag
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On Fri, May 24, 2002 at 09:54:04AM -0700, Robert Love wrote:
> On Fri, 2002-05-24 at 09:45, Marcus Meissner wrote:
> 
> > > Heh, now that is interesting.
> > 
> > Not really, -Os implies -O2, cf gcc/toplev.c:
> 
> Well, according to Alan -Os outperforms -O2.  So either the code is
> smaller _and_ faster - and that is surely interesting - or the code is
> _not_ smaller and -Os is a misnomer.  Seems interesting to me.

-Os implies -O2 + additional size-reducing features:

[hch@sb hch]$ grep -r optimize_size /work/people/hch/gcc/gcc | wc -l
    250
[hch@sb hch]$

A bunch of matches are in ChangeLog and most are target-specific,
but I guess you got the point..