Floating point warnings in CLISP 2.30

Haakon Riiser

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Mar 5, 2003, 9:21:30 PM3/5/03

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If I type two consecutive double (or long) floats outside a certain
range, CLISP complains for no apparent reason. (Well, at least it's
not apparent to me. :-) Typescript follows:

[1]> 1d50
1.0d50
[2]> 1d50

WARNING:
Floating point operation combines numbers of different precision.
See ANSI CL 12.1.4.4 and the CLISP impnotes for details.
The result's actual precision is controlled by
*FLOATING-POINT-CONTAGION-ANSI*.
To shut off this warning, set *WARN-ON-FLOATING-POINT-CONTAGION* to
NIL.1.0d50
[3]>

For double floats, this happens when the number entered is
approximately 1d49 or greater, or 1d-16 or smaller. (Not the
exact limits, but the order of magnitude should be correct.)

Could someone please explain what this is about? I've checked the
impnotes, but I couldn't find anything that explained it.
Thanks in advance.

--
Haakon

Sam Steingold

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Mar 6, 2003, 12:30:54 PM3/6/03

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> * In message <slrnb6dc59....@s.hn.org>
> * On the subject of "Floating point warnings in CLISP 2.30"
> * Sent on Thu, 06 Mar 2003 02:21:30 GMT

> * Honorable Haakon Riiser <hak...@fys.uio.no> writes:
>
> If I type two consecutive double (or long) floats outside a certain
> range, CLISP complains for no apparent reason. (Well, at least it's
> not apparent to me. :-) Typescript follows:
> [1]> 1d50
> 1.0d50
> [2]> 1d50
>
> WARNING:
> Floating point operation combines numbers of different precision.
> See ANSI CL 12.1.4.4 and the CLISP impnotes for details.
> The result's actual precision is controlled by
> *FLOATING-POINT-CONTAGION-ANSI*.
> To shut off this warning, set *WARN-ON-FLOATING-POINT-CONTAGION* to
> NIL.1.0d50

I do not observe this.
what version are you using?
what platform?
2.30 indeed has some problems that have been fixed in the CVS.

--
Sam Steingold (http://www.podval.org/~sds) running RedHat8 GNU/Linux
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All extremists should be taken out and shot.

Haakon Riiser

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Mar 6, 2003, 2:29:46 PM3/6/03

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[Sam Steingold]

>> If I type two consecutive double (or long) floats outside a

>> certain range, CLISP complains for no apparent reason. [...]

> I do not observe this. what version are you using?

2.30, as stated in the subject.

> what platform?

Linux x86 (Slackware 8.1 and Red Hat 7.1).

--
Haakon

Eduardo Muñoz

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Mar 6, 2003, 3:56:01 PM3/6/03

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Sam Steingold <s...@gnu.org> writes:

> > * In message <slrnb6dc59....@s.hn.org>
> > * On the subject of "Floating point warnings in CLISP 2.30"
> > * Sent on Thu, 06 Mar 2003 02:21:30 GMT
> > * Honorable Haakon Riiser <hak...@fys.uio.no> writes:
> >
> > If I type two consecutive double (or long) floats outside a certain
> > range, CLISP complains for no apparent reason. (Well, at least it's
> > not apparent to me. :-) Typescript follows:
> > [1]> 1d50
> > 1.0d50
> > [2]> 1d50
> >
> > WARNING:
> > Floating point operation combines numbers of different precision.
> > See ANSI CL 12.1.4.4 and the CLISP impnotes for details.
> > The result's actual precision is controlled by
> > *FLOATING-POINT-CONTAGION-ANSI*.
> > To shut off this warning, set *WARN-ON-FLOATING-POINT-CONTAGION* to
> > NIL.1.0d50
>
> I do not observe this.
> what version are you using?
> what platform?
> 2.30 indeed has some problems that have been fixed in the CVS.

It happens on windows[1] too:

[1]> (lisp-implementation-version)
"2.30 (released 2002-09-15) (built 3241070561) (memory 3251987657)"
[2]> 1d50
1.0d50
[3]> 1d50

WARNING:
Floating point operation combines numbers of different precision.
See ANSI CL 12.1.4.4 and the CLISP impnotes for details.
The result's actual precision is controlled by
*FLOATING-POINT-CONTAGION-ANSI*.
To shut off this warning, set *WARN-ON-FLOATING-POINT-CONTAGION* to NIL.1.0d50

[4]>

[1] Windows 2000 to be exact.

--

Eduardo Muñoz
http://213.97.131.125/