From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27330 invoked by alias); 26 May 2005 18:10:01 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 27303 invoked by uid 22791); 26 May 2005 18:09:58 -0000 Received: from smtpout02-04.prod.mesa1.secureserver.net (HELO smtpout02-04.prod.mesa1.secureserver.net) (64.202.165.194) by sourceware.org (qpsmtpd/0.30-dev) with SMTP; Thu, 26 May 2005 18:09:58 +0000 Received: (qmail 23057 invoked from network); 26 May 2005 18:09:56 -0000 Received: from unknown (24.96.113.81) by smtpout02-04.prod.mesa1.secureserver.net (64.202.165.194) with ESMTP; 26 May 2005 18:09:56 -0000 Message-ID: <429610BC.9050408@coyotegulch.com> Date: Thu, 26 May 2005 18:49:00 -0000 From: Scott Robert Ladd User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050512) MIME-Version: 1.0 To: Dave Korn CC: 'Morten Welinder' , gcc@gcc.gnu.org Subject: Re: Sine and Cosine Accuracy References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2005-05/txt/msg01444.txt.bz2 Dave Korn wrote: > Well, as long as they're under the control of a flag that also makes it > clear that they are *also* unsafe math optimisations, I wouldn't object. But they are *not* unsafe for *all* applications. An ignorant user may not understand the ramifications of "unsafe" math -- however, the current documentation is quite vague as to why these optimizations are unsafe, and people thus become paranoid and avoid -ffast-math when it would be to their benefit. First and foremost, GCC should conform to standards. *However*, I see nothing wrong with providing additional capability for those who need it, without combining everything "unsafe" under one umbrella. > But you can't just replace a call to the ANSI C 'sin' function with an > invocation of the x87 fsin intrinsic, because they aren't the same, and the > intrinsic is non-ansi-compliant. Nobody said they were. ..Scott