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Re: How to get mantissa of long double?

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.lang.c++
Subject Re: How to get mantissa of long double?
Date 2021-10-07 10:23 +0200
Organization A noiseless patient Spider
Message-ID <sjmaqa$40s$1@dont-email.me> (permalink)
References (14 earlier) <sjkjpl$aa2$1@redfloyd.dont-email.me> <sjm0ui$la0$1@gioia.aioe.org> <sjm3j4$r5v$2@dont-email.me> <sjm4le$1f2$2@dont-email.me> <sjm4s5$2o0$1@dont-email.me>

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On 07/10/2021 08:42, Bonita Montero wrote:
> Am 07.10.2021 um 08:38 schrieb Bonita Montero:
>> Am 07.10.2021 um 08:20 schrieb David Brown:
>>
>>> C++20 added std::endian for convenience and standardisation of common
>>> compiler features for endianness:
>>
>> Why an endianess check here ?
>> There are no big-endian machines with 80 bit FP.
> 
> Oh, I just remembered the 68K FPUs. These have 80 bit FP.
> But 68K is dead today.

The 68k ISA lives on in the microcontroller world, as the ColdFire
processors, though I don't believe any new ColdFire microcontrollers
have been released since NXP bought Freescale in 2015.  Even at that
stage it was no longer a major development line for Freescale.  A decade
or so before that, ColdFire was one of the most popular architectures in
small network devices such as SOHO NAT routers, and was the main target
for the MMU-less Linux version ucLinux.  This was all long after the 68k
was gone from desktops, workstations, home computers, etc.

(Because ucLinux does not support fork(), this lead to an increased use
of spawn() instead of fork-exec, which then made porting to Windows
easier.  So if you use any *nix-heritage software on your Windows
machine, that may be partly thanks to the 68k architecture.)

Some of the 68k-based microcontrollers are immortal.  People still make
devices using the renowned 68332, though it is around 30 years old.

However, few of these embedded uses used floating point, and the the
bigger ColdFire processors with hardware floating point support all used
64-bit floats.  80-bit floats were used in the 68882 FPU co-processor,
and the 68040 and 68060 processors.

The first serious electronics board I designed had a 68332 with a 68882
co-processor, many years ago.  (The current version of the same system
is, unsurprisingly, ARM based.)

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How to get mantissa of long double? wij <wyniijj@gmail.com> - 2021-10-01 08:37 -0700
  Re: How to get mantissa of long double? RadicalRabbit@theburrow.co.uk - 2021-10-01 16:09 +0000
    Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-01 14:05 -0400
      Re: How to get mantissa of long double? wij <wyniijj@gmail.com> - 2021-10-01 17:23 -0700
        Re: How to get mantissa of long double? Manfred <noname@add.invalid> - 2021-10-02 18:58 +0200
          Re: How to get mantissa of long double? Manfred <noname@add.invalid> - 2021-10-02 19:21 +0200
  Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-01 19:18 +0200
    Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-01 19:20 +0200
      Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-01 19:25 +0200
        Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-01 19:53 +0200
          Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-03 08:09 +0200
            Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-03 11:15 +0100
              Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-03 12:19 +0200
                Re: How to get mantissa of long double? red floyd <no.spam@its.invalid> - 2021-10-03 18:03 -0700
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-04 09:52 +0200
                Re: How to get mantissa of long double? Juha Nieminen <nospam@thanks.invalid> - 2021-10-04 09:59 +0000
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-04 13:50 +0200
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-04 20:04 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-05 07:12 +0200
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-05 09:47 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-05 16:46 +0200
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-05 19:04 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-05 19:13 +0200
                Re: How to get mantissa of long double? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-05 09:04 -0700
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-05 19:14 +0200
                Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-05 19:21 +0100
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-06 07:58 +0200
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-06 08:11 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-06 10:25 +0200
                Re: How to get mantissa of long double? scott@slp53.sl.home (Scott Lurndal) - 2021-10-06 14:25 +0000
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-06 16:53 +0200
                Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-06 12:12 +0100
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-06 14:48 +0200
                Re: How to get mantissa of long double? red floyd <no.spam.here@its.invalid> - 2021-10-06 09:44 -0700
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-06 18:52 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-06 19:02 +0200
                Re: How to get mantissa of long double? Juha Nieminen <nospam@thanks.invalid> - 2021-10-07 05:35 +0000
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-07 08:20 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-07 08:38 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-07 08:42 +0200
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-07 10:23 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-08 20:23 +0200
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-09 10:23 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-09 10:50 +0200
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-09 09:02 +0000
                Re: How to get mantissa of long double? scott@slp53.sl.home (Scott Lurndal) - 2021-10-09 14:57 +0000
                Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-09 12:16 +0100
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-09 15:10 +0200
                Re: How to get mantissa of long double? red floyd <no.spam.here@its.invalid> - 2021-10-09 10:26 -0700
                Re: How to get mantissa of long double? Vir Campestris <vir.campestris@invalid.invalid> - 2021-10-12 21:23 +0100
                Re: How to get mantissa of long double? RadicalRabbit@theburrow.co.uk - 2021-10-13 10:30 +0000
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-07 08:38 +0200
                Re: How to get mantissa of long double? Juha Nieminen <nospam@thanks.invalid> - 2021-10-08 04:37 +0000
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-08 07:54 +0200
                Re: How to get mantissa of long double? red floyd <no.spam.here@its.invalid> - 2021-10-07 22:44 -0700
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-07 08:17 +0200
                Re: How to get mantissa of long double? Juha Nieminen <nospam@thanks.invalid> - 2021-10-08 04:39 +0000
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-08 09:25 +0200
                Re: How to get mantissa of long double? scott@slp53.sl.home (Scott Lurndal) - 2021-10-08 14:34 +0000
                Re: How to get mantissa of long double? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-10-06 13:57 -0700
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-05 19:34 +0000
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-05 19:33 +0000
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-05 10:19 +0000
                Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-04 14:06 +0100
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-04 16:12 +0200
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 16:15 +0000
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 16:15 +0000
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-05 09:48 +0200
                Re: How to get mantissa of long double? Juha Nieminen <nospam@thanks.invalid> - 2021-10-05 05:19 +0000
                Re: How to get mantissa of long double? David Brown <david.brown@hesbynett.no> - 2021-10-05 10:00 +0200
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-05 16:47 +0200
                Re: How to get mantissa of long double? scott@slp53.sl.home (Scott Lurndal) - 2021-10-04 14:37 +0000
                Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-04 16:53 +0200
                Re: How to get mantissa of long double? scott@slp53.sl.home (Scott Lurndal) - 2021-10-04 17:08 +0000
                Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-04 20:22 +0100
    Re: How to get mantissa of long double? Bart <bc@freeuk.com> - 2021-10-01 19:09 +0100
      Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-01 20:16 +0200
  Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-01 18:53 +0000
    Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-01 20:19 -0400
      Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-02 02:16 +0000
        Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-02 01:28 -0400
        Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-02 01:56 -0400
          Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-02 10:59 +0000
            Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-02 14:57 -0400
            Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-02 15:37 -0400
              Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-03 00:47 +0000
                Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-03 23:42 -0400
                Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 04:35 +0000
  Re: How to get mantissa of long double? Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-02 12:09 +0200
  Re: How to get mantissa of long double? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-10-02 21:00 +0200
    Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-02 15:12 -0400
      Re: How to get mantissa of long double? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-10-02 21:23 +0200
        Re: How to get mantissa of long double? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-10-02 21:27 +0200
          Re: How to get mantissa of long double? Manfred <noname@add.invalid> - 2021-10-02 23:19 +0200
        Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-03 23:43 -0400
      Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-03 00:45 +0000
        Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-03 23:31 -0400
          Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 04:34 +0000
            Re: How to get mantissa of long double? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-04 11:30 -0400
              Re: How to get mantissa of long double? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 16:19 +0000
    Re: How to get mantissa of long double? wij <wyniijj@gmail.com> - 2021-10-03 00:35 -0700
  Re: How to get mantissa of long double? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-10-03 15:02 +0100
    Re: How to get mantissa of long double? wij <wyniijj@gmail.com> - 2021-10-03 18:46 -0700

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