From owner-freebsd-hackers Wed Jan 5 1: 9:49 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from gilgamesch.bik-gmbh.de (gilgamesch.bik-gmbh.de [194.233.237.194]) by hub.freebsd.org (Postfix) with ESMTP id B5F5D14E4A for ; Wed, 5 Jan 2000 01:09:46 -0800 (PST) (envelope-from cracauer@gilgamesch.bik-gmbh.de) Received: (from cracauer@localhost) by gilgamesch.bik-gmbh.de (8.9.3/8.7.3) id KAA68619; Wed, 5 Jan 2000 10:09:09 +0100 (MET) Date: Wed, 5 Jan 2000 10:09:09 +0100 From: Martin Cracauer To: mauzi@poli.hu Cc: hackers@FreeBSD.ORG Subject: Re: [OFFTOPIC] alt. C compiler Message-ID: <20000105100909.B63545@cons.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: ; from Gergely EGERVARY on Tue, Jan 04, 2000 at 07:32:13PM +0100 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In , Gergely EGERVARY wrote: > I have just upgraded my system to -current w/egcs 2.95.2 and I have > several problems with it, especially when using optimizations (-O2 and > such) When your code breaks when using -O2 or higher, don't do that, use just -O! Almost all examples I've seen where people claimed newer gcc's broke their code are triggered by unclean C code that isn't strictly ANSI C conformant (also see the other thread about ieeefp and floating point exceptions). As far as I understand, the gcc people try to keep the -O option compatible in a way that it doesn't break code that didn't break in earlier versions of gcc. This is exactly the option you need, it's a service for you and you should use it unless you are absolutely sure your code is valid. There are examples of -O2 or higher breaking valid code, but they are much less common than implied. And such issues were in 2.7.x was well, that's the reason the base system is compiled with -O. Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer http://www.cons.org/cracauer/ BSD User Group Hamburg, Germany http://www.bsdhh.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message