From owner-freebsd-alpha Mon Mar 6 12:33:49 2000 Delivered-To: freebsd-alpha@freebsd.org Received: from alcanet.com.au (mail.alcanet.com.au [203.62.196.10]) by hub.freebsd.org (Postfix) with ESMTP id A009437BF4A; Mon, 6 Mar 2000 12:33:38 -0800 (PST) (envelope-from jeremyp@gsmx07.alcatel.com.au) Received: by border.alcanet.com.au id <115205>; Tue, 7 Mar 2000 07:34:17 +1100 Content-return: prohibited From: Peter Jeremy Subject: Re: alpha/17032: strtod(3) floating exception In-reply-to: <20000306154855R.nobu@rd.isac.co.jp>; from nobu@rd.isac.co.jp on Mon, Mar 06, 2000 at 05:49:54PM +1100 To: Nobuhiro Yasutomi Cc: gnats-admin@FreeBSD.ORG, freebsd-alpha@FreeBSD.ORG Message-Id: <00Mar7.073417est.115205@border.alcanet.com.au> MIME-version: 1.0 X-Mailer: Mutt 1.0i Content-type: text/plain; charset=us-ascii References: <20000306154855R.nobu@rd.isac.co.jp> Date: Tue, 7 Mar 2000 07:34:17 +1100 Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On 2000-Mar-06 17:49:54 +1100, Nobuhiro Yasutomi wrote: > By the way, I found other case to make `Floating point exception' >the value is "10e-323". This case happen with `-mieee' option. >When without `-mieee', strtod retrun value to 0. But FreeBSD i386's >strtod make 9.88131e-323. Which is collect behavier? Unlike the i386, the Alpha doesn't support denormalised numbers (eg doubles less than ~2.225e-308) in hardware. By default they truncate to zero. Correct IEEE behaviour relies on a combination of compiler (the -mieee flag) and kernel support. As for 10e-323, that number cannot be represented as a double (for denormalised numbers, only integer multiples of ~4.940656e-324 can be represented). The closest representable value is 9.88131e-323 - which is what the i386 reported. Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message