From owner-freebsd-current Thu Sep 23 12:30:34 1999 Delivered-To: freebsd-current@freebsd.org Received: from dorifer.heim3.tu-clausthal.de (dorifer.heim3.tu-clausthal.de [139.174.243.252]) by hub.freebsd.org (Postfix) with ESMTP id 8DE1D15EE9 for ; Thu, 23 Sep 1999 12:29:30 -0700 (PDT) (envelope-from olli@dorifer.heim3.tu-clausthal.de) Received: (from olli@localhost) by dorifer.heim3.tu-clausthal.de (8.8.8/8.8.8) id VAA01658 for freebsd-current@FreeBSD.ORG; Thu, 23 Sep 1999 21:28:15 +0200 (CEST) (envelope-from olli) Date: Thu, 23 Sep 1999 21:28:15 +0200 (CEST) From: Oliver Fromme Message-Id: <199909231928.VAA01658@dorifer.heim3.tu-clausthal.de> To: freebsd-current@FreeBSD.ORG Subject: Re: gcc optimizer in -current system ... Organization: Administration Heim 3 Reply-To: freebsd-current@FreeBSD.ORG MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: TIN [version 1.2 RZTUC(3) PL2] Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG bsd@picard.mandrakesoft.de wrote in list.freebsd-current: > On Thu, 23 Sep 1999, The Hermit Hacker wrote: > > just curious, but what is the max setting that can be used to compile the > > kernel? > > Works rather nicely here with > > -O6 -mpentiumpro -march=pentiumpro -pipe -s -fexpensive-optimizations > -ffast-math -ffast-math shouldn't have any effect, because the kernel does not contain floating-point code. -ffexp-opt is already included in -O3 (which is the maximum -O value supported by the compiler), so it is redundant, too. The gcc optimizer is traditionally buggy. I wouldn't trust a system compiled with anything more than -O (especially on production servers). The higher optimization levels don't provide much of a speed improvement anyway, sometimes they make the code even slower. YMMV. Regards Oliver -- Oliver Fromme, Leibnizstr. 18/61, 38678 Clausthal, Germany (Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de) "In jedem Stück Kohle wartet ein Diamant auf seine Geburt" (Terry Pratchett) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message