From owner-freebsd-hackers Tue Mar 13 11:48:26 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from burns.conectiva (brutus.conectiva.com.br [200.250.58.146]) by hub.freebsd.org (Postfix) with SMTP id 5030F37B72A for ; Tue, 13 Mar 2001 11:48:19 -0800 (PST) (envelope-from riel@conectiva.com.br) Received: (qmail 3242 invoked by uid 0); 13 Mar 2001 19:47:15 -0000 Received: from dial14.ras.conectiva (HELO imladris.rielhome.conectiva) (root@10.0.8.14) by burns.conectiva with SMTP; 13 Mar 2001 19:47:15 -0000 Received: from localhost (IDENT:riel@localhost [127.0.0.1]) by imladris.rielhome.conectiva (8.11.1/8.11.1) with ESMTP id f2DJfcn02734; Tue, 13 Mar 2001 16:41:38 -0300 Date: Tue, 13 Mar 2001 16:41:38 -0300 (BRST) From: Rik van Riel X-Sender: riel@imladris.rielhome.conectiva To: Charles Randall Cc: "'freebsd-hackers@FreeBSD.ORG'" Subject: Re: gcc optimization problems (RE: optimizing apache with php and nfs mounts) In-Reply-To: <5FE9B713CCCDD311A03400508B8B30130828E8F7@bdr-xcln.corp.matchlogic.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 13 Mar 2001, Charles Randall wrote: > From: David O'Brien [mailto:obrien@FreeBSD.ORG] > >2. The base, system C compiler is known to produce bad code with -O2. > > We have been proclaiming this since as long as I have been with the > > Project. > > Is this an issue with FreeBSD's gcc's or gcc in general? If gcc in > general, are there open PRs on this issue? It's a gcc thing. Linux is having the same problems every once in a while (currently there only seem to be _2_ gcc versions which generate correct code for the Linux kernel ...). OTOH, it is possible to work around gcc problems in the code and code which was initially written for older gcc versions often rely on things which were true in older gcc versions but are no longer true currently ... (especially things depending on certain ordering of instructions and the (non-)presence of memory barriers) regards, Rik -- Virtual memory is like a game you can't win; However, without VM there's truly nothing to lose... http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com.br/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message