Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site rtp47.UUCP Path: utzoo!linus!decvax!mcnc!rti-sel!rtp47!meissner From: meissner@rtp47.UUCP (Michael Meissner) Newsgroups: net.lang.c Subject: Re: More Naughty Bits Message-ID: <132@rtp47.UUCP> Date: Sat, 10-Aug-85 16:04:26 EDT Article-I.D.: rtp47.132 Posted: Sat Aug 10 16:04:26 1985 Date-Received: Mon, 12-Aug-85 23:20:55 EDT References: <575@brl-tgr.ARPA> Reply-To: meissner@rtp47.UUCP (Michael Meissner) Distribution: net Organization: Data General, RTP, NC Lines: 24 Keywords: floating-point In article <575@brl-tgr.ARPA> Cottrell@BRL.ARPA, James writes: >/* >me ->> What other kind of zero is there? >Doug Gwyn -> How about 0.0? > >How about it? Any pattern of all zeros is considered zero by any >*sane* floating point unit. You are perfectly welcome to use insane >FPU's, but then you'd have to write an insane C compiler, wouldn't you? >What's that you say? They're *all* insane? Got to keep the loonies on the path! While I agree with the comment about *sane* floating point, a similar topic was raised in the the ANSI C meetings when discussing the implied initialization of static/extern variables to 0. To my surprise, there is at least one machine out there where 0.0 does not have all bits set to zero! Also, there was some discussion that a NULL pointer might not have all bits zero either, just as long as a zero integer can be converted to the bit pattern used, and vica versa. The reason given was for ring/segment machines, you might want to put in the current segment, or an unused segment. BTW, I believe the machine with the unusual floating point might have been a univac 1100, but I could be mistaken. Michael Meissner Data General ...{ ihnp4, allegra, decvax }!mcnc!rti-sel!rtp47!meissner