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Re: ddfloat library: the behavior of >dd

Date 2026-09-15 13:11 +1000
Subject Re: ddfloat library: the behavior of >dd
Newsgroups comp.lang.forth
References (13 earlier) <6aa7e1b3$1@news.ausics.net> <1188p58$1al9l$1@dont-email.me> <6aa81377$1@news.ausics.net> <1189gnf$1qn4q$1@dont-email.me> <1189l8g$1sbns$1@dont-email.me>
From dxf <dxforth@gmail.com>
Message-ID <6aa8b74f@news.ausics.net> (permalink)
Organization Ausics - https://newsgroups.ausics.net

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On 15/09/2026 6:25 am, Krishna Myneni wrote:
> On 9/14/26 2:08 PM, marcel hendrix wrote:
>> On 9/14/2026 5:32 PM, dxf wrote:
> ...
>> The plain limit here is currently
>> FORTH> S" 1e304" >dd
>>  >DD :: exponent too large or too small
>>
>> That is because I want to be able to write
>> FORTH> S" 10000e303" >dd ddfe. 1.000000000000000000000000000000e307
>>
>> IMO, for all practical purposes this is more than sufficient.
> 
> Yet, one should check whether or not it's technically correct for double-double arithmetic.
> 
> We need to go back to Bailey's ddfun package to see how he did the >DD conversion.
> 
> My two cents.

On regular double-precision systems the limitation will be DD* DD/ which
makes 10^307 math impractical irrespective of >DD .  I suspect Marcel's
80-bit intermediates/variables is giving him a bit more range.

FWIW my latest version is here:

https://pastebin.com/bcbFUZF0

Numbers out of range will be printed as **DD** .  Bug reports welcome.

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Thread

ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-10 19:33 +0200
  Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-10 13:35 -0500
    Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-10 22:10 +0200
      Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-10 16:51 -0500
  Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-11 12:16 +1000
    Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-11 12:05 +0200
      Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-12 00:27 +0200
        Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-11 20:29 -0500
          Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-12 12:02 +1000
            Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-12 10:24 -0500
          Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-12 10:45 +0200
            Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-12 19:51 +1000
            Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-12 22:47 +1000
              Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-13 03:14 +1000
                Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-12 13:02 -0500
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-13 15:44 +1000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-13 09:00 +0200
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-13 20:33 +1000
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-14 13:28 +1000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-14 10:09 +0200
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-14 20:00 +1000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-14 12:22 +0200
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-14 21:59 +1000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-14 14:26 +0200
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-15 01:32 +1000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-14 21:08 +0200
                Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-14 15:25 -0500
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-15 13:11 +1000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-15 14:06 +0200
                Re: ddfloat library: the behavior of >dd dxf <dxforth@gmail.com> - 2026-09-16 00:05 +1000
                Re: ddfloat library: the behavior of >dd anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2026-09-14 15:00 +0000
                Re: ddfloat library: the behavior of >dd marcel hendrix <mhx@iae.nl> - 2026-09-14 21:15 +0200
                Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-14 15:29 -0500
                Re: ddfloat library: the behavior of >dd anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2026-09-14 20:58 +0000
                Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-15 07:33 -0500
                Re: ddfloat library: the behavior of >dd anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2026-09-15 15:53 +0000
                Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-15 15:23 -0500
                Re: ddfloat library: the behavior of >dd Krishna Myneni <krishna.myneni@ccreweb.org> - 2026-09-15 17:53 -0500

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