From owner-freebsd-current@FreeBSD.ORG Mon Apr 25 18:23:45 2005 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1E2FD16A4CE for ; Mon, 25 Apr 2005 18:23:45 +0000 (GMT) Received: from eva.fit.vutbr.cz (eva.fit.vutbr.cz [147.229.10.14]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4D48843D41 for ; Mon, 25 Apr 2005 18:23:42 +0000 (GMT) (envelope-from xdivac02@stud.fit.vutbr.cz) Received: from eva.fit.vutbr.cz (localhost [127.0.0.1]) (8.13.4/8.13.3) with ESMTP id j3PINdi5012667 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Mon, 25 Apr 2005 20:23:39 +0200 (CEST) Received: (from xdivac02@localhost) by eva.fit.vutbr.cz (8.13.4/8.13.3/Submit) id j3PINdGi012665 for current@freebsd.org; Mon, 25 Apr 2005 20:23:39 +0200 (CEST) Date: Mon, 25 Apr 2005 20:23:39 +0200 From: Divacky Roman To: current@freebsd.org Message-ID: <20050425182339.GA10821@stud.fit.vutbr.cz> References: <6.2.1.2.0.20050424204611.072105a0@64.7.153.2> <20050425010242.GA44110@xor.obsecurity.org> <6.2.1.2.0.20050424210422.03d22990@64.7.153.2> <20050425014453.GA59981@xor.obsecurity.org> <426C6B1D.3040704@elischer.org> <20050425061459.GA33247@xor.obsecurity.org> <20050425062106.GB91852@voodoo.oberon.net> <426CF3DE.4000409@samsco.org> <20050425160146.4795fe1b.flynn@energyhq.es.eu.org> <426CF91A.8060907@samsco.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <426CF91A.8060907@samsco.org> User-Agent: Mutt/1.4.2i X-Scanned-By: MIMEDefang 2.49 on 147.229.10.14 Subject: Re: GCC 4.0 [Re: FreeBSD 6 is coming too fast] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Apr 2005 18:23:45 -0000 On Mon, Apr 25, 2005 at 08:05:14AM -0600, Scott Long wrote: > Miguel Mendez wrote: > >On Mon, 25 Apr 2005 07:42:54 -0600 > >Scott Long wrote: > > > > > >>>According to gcc-4.0 release notes, compilation speed for C++ was > >>>dramatically increased, up to 25% IIRC. I think 4.0 is good > >>>candidate for merging into HEAD. > > > > > >>Is this work that you plan on doing for us? > > > > > >Definitely not for 6.0, and I usually avoid .0 releases on critical > >software, but nonetheless it would interesting setting a tinderbox, > >launch a buildworld process with gcc40 and see where/if it breaks. I > >have a spare k6-2 box I could setup for that task. > > > > > >>What about the deprecated language constructs in 4.0? gcc40 revelas some interesting "bugs" in the code... look at hysteria.sk/~neologism/ddb.patch which is 10 minutes try to build kernel with gcc40, look at the sigedness bug (at the bottom of the patch) which is not (I dont know why) revealed by current gcc we use I dont claim the patch is absolutely ok or solves anything but its nice to see > >According to http://gcc.gnu.org/gcc-4.0/changes.html, some of the > >deprecated constructs are not even valid C, so I see this as an > >opportunity to fix buggy code. > > > > > >>What about the lack of exposure that it's > >>had outside of the FSF and Apple development circles? I kinda like the way dfly treats this. they have/had two gccs in tree which allowed them for more smoother transition to the newer one.. > >Exactly the reason why testing will be beneficial. The more tested the > >product on FreeBSD the more robust it will be when it's time to get it > >into the tree. > > > >Cheers, > > Well, I'd caution against jumping into GCC 4.0 just because of the > claims of 25% speed improvement. That's about the single worst reason > to do it. But if you're interested in moving the technology forward, > I'd happily encourage you. The changed language constructs are the big > problem (extern struct foo bar[]; is no longer valid) since you not only > need to sweep the FreeBSD tree for them, you also need to sweep the > ports tree. I have mixed feeling on the value of GCC making sloppy > language extentions available for years and then suddenly revoking them, > and I know others that have been affected by 4.0 aren't terribly happy > either. we will have to import gcc4.x one day just because old gccs tends to be abandoned and not supported anymore. and I personally think that the new gcc is improvement... sure, some work is needed but its not that big deal as it might seem.. just my 2 cents roman