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Mail Archives: pgcc/1999/03/02/17:31:01

Message-Id: <3.0.2.32.19990302210932.0161f044@pop3.digibel.be>
X-Sender: pascutto AT pop3 DOT digibel DOT be
X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.2 (32)
Date: Tue, 02 Mar 1999 21:09:32 +0100
To: pgcc AT delorie DOT com
From: Gian-Carlo Pascutto <GianCarlo DOT Pascutto AT advalvas DOT be>
Subject: Re: gcc-2.7.0 creates faster code than pgcc-1.1.1
Cc: bom AT classic DOT iki DOT rssi DOT ru
In-Reply-To: <01BE64C5.8B5FD140@valya.iki.rssi.ru>
Mime-Version: 1.0
Reply-To: pgcc AT delorie DOT com

At 15:58 2/03/99 +0300, you wrote:
>make CFLAGS="-Os -fomit-frame-pointer -mpentiumpro -march=pentiumpro 
>-fno-exceptions -malign-loops=2 -malign-jumps=2 -malign-functions=2"

The -Os parameter optimizes for size. 

When you compile it with -O6 it will generate speed-optimized code
and it will probably be about 30% faster.

>I send you this fancy executable as attachment and really want to know
>how can this be, why we loose 5% of speed in the 2.9.x gcc code using
>all optimizations invented during past 4 years?
>

Hmm... compare the file sizes and see. Egcs with -Os option should
get you a smaller file. After all, that is what you're optimizing for.

I have to say I didn't really check wheter this is really true but
the -Os parameter is really there for size and not for speed, and
since the difference was only 5%...

Also, please think twice before including long attachements.

I find it TERRIBLY RUDE to include a big and mostly useless attachement 
and then simply state "I'm not on the list myself"

Greetings,
Gian-Carlo

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