From owner-freebsd-current@FreeBSD.ORG Wed Mar 26 09:45:50 2003 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 E626837B405 for ; Wed, 26 Mar 2003 09:45:50 -0800 (PST) Received: from dragon.nuxi.com (trang.nuxi.com [66.93.134.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6D84C43FAF for ; Wed, 26 Mar 2003 09:45:49 -0800 (PST) (envelope-from obrien@NUXI.com) Received: from dragon.nuxi.com (obrien@localhost [127.0.0.1]) by dragon.nuxi.com (8.12.8/8.12.7) with ESMTP id h2QHjdAm083971; Wed, 26 Mar 2003 09:45:43 -0800 (PST) (envelope-from obrien@dragon.nuxi.com) Received: (from obrien@localhost) by dragon.nuxi.com (8.12.8/8.12.8/Submit) id h2QHjZ7a083956; Wed, 26 Mar 2003 09:45:35 -0800 (PST) Date: Wed, 26 Mar 2003 09:45:35 -0800 From: "David O'Brien" To: ljrittle@gcc.gnu.org, freebsd-current@freebsd.org, gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org, nobody@gcc.gnu.org, till@f111.hadiko.de, gcc-gnats@gcc.gnu.org Message-ID: <20030326174535.GA83816@dragon.nuxi.com> References: <20030326130118.8374.qmail@sources.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030326130118.8374.qmail@sources.redhat.com> User-Agent: Mutt/1.4i X-Operating-System: FreeBSD 5.0-CURRENT Organization: The NUXI BSD Group X-Pgp-Rsa-Fingerprint: B7 4D 3E E9 11 39 5F A3 90 76 5D 69 58 D9 98 7A X-Pgp-Rsa-Keyid: 1024/34F9F9D5 X-Spam-Status: No, hits=-26.7 required=5.0 tests=AWL,EMAIL_ATTRIBUTION,IN_REP_TO,QUOTED_EMAIL_TEXT, REFERENCES,REPLY_WITH_QUOTES,USER_AGENT_MUTT autolearn=ham version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) Subject: Re: optimization/10189: pentium4 breaks suns libm code for __ieee754_pow(double x, double y) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: obrien@freebsd.org List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Mar 2003 17:45:55 -0000 On Wed, Mar 26, 2003 at 01:01:18PM -0000, ljrittle@gcc.gnu.org wrote: > Synopsis: pentium4 breaks suns libm code for __ieee754_pow(double x, double y) Beautiful email!! > Special secret #2: Although the FSF-side does want to improve all > code generation (and I think proper PRs RE CPU switches will be > looked at by someone given enough time) be aware that -O2 without > special arch flags is probably the most stable for any given CPU > for any given gcc release. Do you really want to trust a kernel > built with optimization flags and arch flags that near zero or zero > people have fully tested? Doubtful. However, inline with secret > #1 and by virtual of being digital, if even one person tests it > (i.e. yourself) and it appears OK, then it is probably safe to at > least attempt to build a kernel and run it. FreeBSD has for years recommended -O[1] vs. -O2. Do you think there is value in having the GCC test suite runs you do at FreeBSD.org do runs with both settings? To also do runs with the newer CPU types?