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Re: "A diagram of C23 basic types"

From Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups comp.lang.c
Subject Re: "A diagram of C23 basic types"
Date 2025-06-26 17:10 -0700
Organization None to speak of
Message-ID <87y0teyrg7.fsf@nosuchdomain.example.com> (permalink)
References (3 earlier) <20250428162738.00007c1d@yahoo.com> <103j290$3bv4a$1@dont-email.me> <8734bm1eqz.fsf@nosuchdomain.example.com> <20250626235916.00003314@yahoo.com> <lGi7Q.55256$Ra5f.13001@fx13.iad>

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scott@slp53.sl.home (Scott Lurndal) writes:
[...]
> But not all decimal floating point implementations used "hex floating point".
>
> Burroughs medium systems had BCD floating point - one of the advantages
> was that it could exactly represent any floating point number that
> could be specified with a 100 digit mantissa and a 2 digit exponent.

BCD uses 4 bits to represent values from 0 to 9.  That's about 83%
efficent relative to pure binary.  (And it still can't represent 1/3.)

Another option (I think IBM has implemented this) is to use 10 bits
to represent values from 0 to 999, taking advantage of the nice
coincidence that 2**10 is barely bigger than 10**3.  That's more
than 99.6% efficient relative to pure binary.  Of course it's still
more complicated to implement.

[...]

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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Thread

Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-06-26 09:01 +0000
  Re: "A diagram of C23 basic types" Richard Heathfield <rjh@cpax.org.uk> - 2025-06-26 13:27 +0100
    Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-06-27 00:39 +0000
      Re: "A diagram of C23 basic types" Richard Heathfield <rjh@cpax.org.uk> - 2025-06-27 02:40 +0100
        Re: "A diagram of C23 basic types" "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-06-26 19:33 -0700
        Re: "A diagram of C23 basic types" BGB <cr88192@gmail.com> - 2025-06-28 14:16 -0500
        Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-07-15 19:41 +0000
          Re: "A diagram of C23 basic types" Richard Heathfield <rjh@cpax.org.uk> - 2025-07-16 03:55 +0100
            Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-07-20 00:16 +0000
              Re: "A diagram of C23 basic types" Richard Heathfield <rjh@cpax.org.uk> - 2025-07-20 07:58 +0100
                Re: "A diagram of C23 basic types" Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-07-20 11:28 +0200
    Re: "A diagram of C23 basic types" Kaz Kylheku <643-408-1753@kylheku.com> - 2025-06-29 04:44 +0000
      Re: "A diagram of C23 basic types" Michael S <already5chosen@yahoo.com> - 2025-06-29 17:13 +0300
  Re: "A diagram of C23 basic types" antispam@fricas.org (Waldek Hebisch) - 2025-06-26 12:51 +0000
    Re: "A diagram of C23 basic types" "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-06-26 13:23 -0700
    Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-06-26 23:58 +0000
      Re: "A diagram of C23 basic types" antispam@fricas.org (Waldek Hebisch) - 2025-06-27 03:51 +0000
        Re: "A diagram of C23 basic types" David Brown <david.brown@hesbynett.no> - 2025-06-27 13:44 +0200
      Re: "A diagram of C23 basic types" scott@slp53.sl.home (Scott Lurndal) - 2025-06-27 14:01 +0000
  Re: "A diagram of C23 basic types" David Brown <david.brown@hesbynett.no> - 2025-06-26 15:57 +0200
    Re: "A diagram of C23 basic types" Richard Heathfield <rjh@cpax.org.uk> - 2025-06-26 16:10 +0100
  Re: "A diagram of C23 basic types" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-06-26 12:31 -0700
    Re: "A diagram of C23 basic types" Michael S <already5chosen@yahoo.com> - 2025-06-26 23:59 +0300
      Re: "A diagram of C23 basic types" scott@slp53.sl.home (Scott Lurndal) - 2025-06-26 21:09 +0000
        Re: "A diagram of C23 basic types" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-06-26 17:10 -0700
          Re: "A diagram of C23 basic types" Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-06-27 04:33 +0200
            Re: "A diagram of C23 basic types" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-06-27 17:56 -0700
              Re: "A diagram of C23 basic types" Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-06-29 05:03 +0200
                Re: "A diagram of C23 basic types" James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-06-28 23:18 -0400
                Re: "A diagram of C23 basic types" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-06-28 20:37 -0700
                Re: "A diagram of C23 basic types" Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-06-29 20:48 +0200
                Re: "A diagram of C23 basic types" James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-06-30 21:59 -0400
                Re: "A diagram of C23 basic types" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-06-28 20:51 -0700
                Re: "A diagram of C23 basic types" Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-06-29 20:40 +0200
                Re: "A diagram of C23 basic types" - correction Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-06-29 20:52 +0200
                Re: "A diagram of C23 basic types" - correction "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-06-29 12:14 -0700
          Re: "A diagram of C23 basic types" scott@slp53.sl.home (Scott Lurndal) - 2025-06-27 14:02 +0000
        Re: "A diagram of C23 basic types" Michael S <already5chosen@yahoo.com> - 2025-06-27 14:52 +0300
          Re: "A diagram of C23 basic types" Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-06-27 20:48 +0200
          Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-06-28 23:59 +0000
            Re: "A diagram of C23 basic types" James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-06-29 09:23 -0400
              Re: "A diagram of C23 basic types" Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-07-29 00:56 +0000
                Re: "A diagram of C23 basic types" James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-07-29 21:13 -0400

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