From owner-freebsd-hackers@FreeBSD.ORG  Sun Mar 21 04:14:14 2004
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 83D6016A4D0
	for <hackers@freebsd.org>; Sun, 21 Mar 2004 04:14:14 -0800 (PST)
Received: from mail.acis.com.au (atlantis.acis.com.au [203.14.230.6])
	by mx1.FreeBSD.org (Postfix) with SMTP id 11F1E43D39
	for <hackers@freebsd.org>; Sun, 21 Mar 2004 04:14:13 -0800 (PST)
	(envelope-from andymac@bullseye.apana.org.au)
Received: (qmail 96849 invoked from network); 21 Mar 2004 12:14:10 -0000
Received: from dialup14-async.civ.acis.com.au (HELO bullseye.apana.org.au)
	(203.10.77.14)
	by atlantis.acis.com.au with SMTP; 21 Mar 2004 12:14:10 -0000
Received: from bullseye.apana.org.au (localhost.apana.org.au [127.0.0.1])
	i2L5ruOj033284;	Sun, 21 Mar 2004 16:53:56 +1100 (EST)
	(envelope-from andymac@bullseye.apana.org.au)
Received: from localhost (andymac@localhost)i2L5ru75033281;
	Sun, 21 Mar 2004 16:53:56 +1100 (EST)
	(envelope-from andymac@bullseye.apana.org.au)
Date: Sun, 21 Mar 2004 16:53:56 +1100 (EST)
From: Andrew MacIntyre <andymac@bullseye.apana.org.au>
To: Garance A Drosihn <drosih@rpi.edu>
In-Reply-To: <p0602044cbc827481888c@[128.113.24.47]>
Message-ID: <20040321164733.N33243@bullseye.apana.org.au>
References: <p0602044cbc827481888c@[128.113.24.47]>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: hackers@freebsd.org
Subject: Re: Adventures with gcc: code vs object-code size
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 21 Mar 2004 12:14:14 -0000

On Sat, 20 Mar 2004, Garance A Drosihn wrote:

> I am not a compilier guru, so I suspect it would take me hours to
> pin this down.  I don't want to do that, so I'm wondering if anyone
> understands how such a minor code-change can POSSIBLY cause such a
> huge change in resulting object file...  I also wonder if this same
> issue pops up in other programs, too.

I'm not a guru either, but I've seen a case where adding code (mostly
switch clauses) caused a size reduction (on i386 anyway)...

Depending on the optimisation level, it might be that the added code is
affecting the heuristics gcc is using for inlined functions etc.

--
Andrew I MacIntyre                     "These thoughts are mine alone..."
E-mail: andymac@bullseye.apana.org.au  (pref) | Snail: PO Box 370
        andymac@pcug.org.au             (alt) |        Belconnen  ACT  2616
Web:    http://www.andymac.org/               |        Australia