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Re: C arithmetic, was Software proofs, was Are there different

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Hans-Peter Diettrich <DrDiettrich1@netscape.net> writes:
>AFAIK use IEEE-754 floating point numbers still sign-magnitude
>representation.
>Then the same representation of integral numbers may have advantages in
>computations.

Such as?  Anyway, whatever these advantages may be, they have not been
enough to prevent the extermination of sign-magnitude integers.

>[I presume the sign-magnitude is to enable the hidden bit trick,
>which doesn't apply in unscaled integers. -John]

With a ones-complement or two's-complement mantissa the hidden bit
would just have the same sign as the sign bit, so this trick is not
tied to sign-magnitude representation.

Some years ago someone sketched a two's-complement representation for
FP (that also includes the exponent), but I did not quite get the
details.  Anyway, I expect that whatever the advantages of that
representation are, they are not enough to justify the transition
cost.

- anton
--
M. Anton Ertl
anton@mips.complang.tuwien.ac.at
http://www.complang.tuwien.ac.at/anton/
[PDP-6/10 floating point was two's complement.  As someone else recently noted, that
meant they could use fixed point compare instructions. -John]

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Re: Are there different programming languages that are compiled to the same intermediate language? Martin Ward <mwardgkc@gmail.com> - 2023-01-31 14:04 +0000
  Re: Are there different programming languages that are compiled to the same intermediate language? arnold@freefriends.org (Aharon Robbins) - 2023-02-01 08:07 +0000
    Re: Software proofs, was Are there different programming languages that are compiled to the same intermediate language? Spiros Bousbouras <spibou@gmail.com> - 2023-02-05 15:14 +0000
      Re: C arithmetic, was Software proofs, was Are there different Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-05 16:14 -0800
        Re: C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-06 13:26 -0800
          Re: C arithmetic, was Software proofs, was Are there different Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2023-02-07 14:31 +0100
            Re: C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-08 01:10 -0800
              Re: C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-09 00:26 -0800
                Re: C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-11 00:01 -0800
                Re: C arithmetic, was Software proofs, was Are there different drb@ihatespam.msu.edu (Dennis Boone) - 2023-02-12 04:37 +0000
            Re: C arithmetic, was Software proofs, was Are there different anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2023-02-08 10:19 +0000
              Re: C arithmetic, was Software proofs, was Are there different Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2023-02-10 19:11 +0100
                Re: C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-10 23:47 -0800
                Re: C arithmetic, was Software proofs, was Are there different anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2023-02-11 22:34 +0000
                Re: old floating point, C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-11 22:48 -0800
            Re: C arithmetic, was Software proofs, was Are there different Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2023-02-08 15:24 +0100
              Re: C arithmetic, was Software proofs, was Are there different gah4 <gah4@u.washington.edu> - 2023-02-09 00:37 -0800

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