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Re: UNION global variabl initialize

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Ike Naar <ike@iceland.freeshell.org> wrote:
> On 2011-09-13, Lung.S.Wu <lung.s.wu@gmail.com> wrote:
> > Is there any system which defines NULL, floating point 0 not all bits-zero?

> This is a FAQ.
> http://c-faq.com/null/machexamp.html

And I remember to have read that on 286 and 386 machines without
a math co-processor floating point operations were done via soft-
ware emulation using a non-IEEE 754 format where 0.0 had a non-
all-bits-zero representation (but I may mis-remember, never ha-
ving used that kind of machines;-). And, while I have no expe-
rience with embedded systems, I wouldn't be too surprised if
one would find something similar on those. Furthermore, there
is nothing that keeps people developing new architectures that
don't use IEEE 754 or have non-zero NULL pointers...

So it's not really so much the question if such machines exit
but that, since the C standard doesn't require an all-bits-zero
representation for NULL pointers and 0.0 floating point values
(maybe mostly for historical reasons) it simply can't mandate
that more than one member of a static union is initialized to
a "zero" value.
                             Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt@toerring.de
   \__________________________      http://toerring.de

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Thread

UNION global variabl initialize "Lung.S.Wu" <lung.s.wu@gmail.com> - 2011-09-12 09:38 -0700
  Re: UNION global variabl initialize jt@toerring.de (Jens Thoms Toerring) - 2011-09-12 17:08 +0000
  Re: UNION global variabl initialize Kenneth Brody <kenbrody@spamcop.net> - 2011-09-12 15:02 -0400
    Re: UNION global variabl initialize "Lung.S.Wu" <lung.s.wu@gmail.com> - 2011-09-12 22:10 -0700
      Re: UNION global variabl initialize Ike Naar <ike@iceland.freeshell.org> - 2011-09-13 07:10 +0000
        Re: UNION global variabl initialize jt@toerring.de (Jens Thoms Toerring) - 2011-09-13 11:42 +0000
          Re: UNION global variabl initialize Robert Wessel <robertwessel2@yahoo.com> - 2011-09-13 13:34 -0500
  Re: UNION global variabl initialize China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-09-12 22:34 -0700
    Re: UNION global variabl initialize "Lung.S.Wu" <lung.s.wu@gmail.com> - 2011-09-12 23:07 -0700
      Re: UNION global variabl initialize China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-09-12 23:35 -0700
      Re: UNION global variabl initialize James Kuyper <jameskuyper@verizon.net> - 2011-09-13 08:09 -0400
    Order of UNION members (was Re: UNION global variabl initialize) Kenneth Brody <kenbrody@spamcop.net> - 2011-09-13 16:29 -0400
      Re: Order of UNION members (was Re: UNION global variabl initialize) James Kuyper <jameskuyper@verizon.net> - 2011-09-13 17:45 -0400
        Re: Order of UNION members (was Re: UNION global variabl initialize) "Lung.S.Wu" <lung.s.wu@gmail.com> - 2011-09-13 19:32 -0700
          Re: Order of UNION members (was Re: UNION global variabl initialize) James Kuyper <jameskuyper@verizon.net> - 2011-09-14 06:59 -0400
            Re: Order of UNION members (was Re: UNION global variabl initialize) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-14 15:08 +0100
        Re: Order of UNION members (was Re: UNION global variabl initialize) Kenneth Brody <kenbrody@spamcop.net> - 2011-09-14 12:50 -0400
          Re: Order of UNION members (was Re: UNION global variabl initialize) James Kuyper <jameskuyper@verizon.net> - 2011-09-14 13:21 -0400

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