From owner-freebsd-hackers  Wed May 29 12:52:19 1996
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id MAA00523
          for hackers-outgoing; Wed, 29 May 1996 12:52:19 -0700 (PDT)
Received: from diablo.ppp.de (diablo.ppp.de [193.141.101.34])
          by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id MAA00518;
          Wed, 29 May 1996 12:52:17 -0700 (PDT)
Received: from allegro.lemis.de by diablo.ppp.de with smtp
	(Smail3.1.28.1 #1) id m0uOqSM-000QYSC; Wed, 29 May 96 20:58 MET DST
From: grog@lemis.de (Greg Lehey)
Organisation: LEMIS, Schellnhausen 2, 36325 Feldatal, Germany
Phone: +49-6637-919123
Fax:   +49-6637-919122
Received: (grog@localhost) by allegro.lemis.de (8.6.9/8.6.9) 
	id UAA24634; Wed, 29 May 1996 20:48:12 +0200
Message-Id: <199605291848.UAA24634@allegro.lemis.de>
Subject: Re: I HATE OPTIMISING COMPILERS
To: gpalmer@FreeBSD.ORG (Gary Palmer)
Date: Wed, 29 May 1996 20:48:12 +0200 (MET DST)
Cc: hackers@FreeBSD.ORG (FreeBSD Hackers)
In-Reply-To: <1403.833392536@palmer.demon.co.uk> from "Gary Palmer" at May 29, 96 06:55:36 pm
X-Mailer: ELM [version 2.4 PL23]
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

Gary Palmer writes:
>
> Greg Lehey wrote in message ID
> <199605291108.NAA20309@allegro.lemis.de>:
>> Well, it looks like what you hate is a broken compiler.  That's not
>> optimizing, that's just broken.
>
> Well, it was the -O which was the culprit, which (to me at least)
> points to a problem in the optimisation code.

Sure.  The compiler's broken in the optimizer.  But it's broken.  It's
not the purpose of optimization to change the function of the code.

>> How come you didn't use gdb to follow up the problem?
>
> Would gdb have been able to track this down? I'm not so sure. That,
> and I have never liked gdb. I used gdb to track the execution path and
> then dove into the sources to see what was going on.

I assume you wrote this before you saw my example.  I'd be very
interested to hear what you say to that.

Greg