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Groups > comp.lang.forth > #50447
| From | "HAA" <someone@microsoft.com> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: fatan2 2012 |
| Date | 2016-08-25 02:16 +1000 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <npkh74$37o$1@gioia.aioe.org> (permalink) |
| References | <npdse1$1s5g$1@gioia.aioe.org> <2016Aug22.120058@mips.complang.tuwien.ac.at> <npgdmc$1pmf$1@gioia.aioe.org> <2016Aug23.131107@mips.complang.tuwien.ac.at> |
Anton Ertl wrote: > "HAA" <someone@microsoft.com> writes: > >Anton Ertl wrote: > >> ... > >> This is a specification, not a test case. > > > >Then it would appear to be a redundant specification. > > pi and -pi both represent the same direction, and are within the range > of the function, so no, specifying which of the two is returned is not > redundant. A +ve value for y specifies the 1st or 2nd quadrant. The result cannot be anything but +ve. A -ve value for y specifies the 3rd or 4th quadrant. The result cannot be anything but -ve. The extra specification is redundant. > >> >SwiftForth i386-Win32 3.6.2 04-Apr-2016 > >> > > >> >0e pad f! pad 1 floats dump > >> > 4809E8 00 00 00 00 00 00 00 00 ........ ok > >> >0e fnegate pad f! pad 1 floats dump > >> > 4809E8 00 00 00 00 00 00 00 80 ........ ok > >> > > >> >0e fdup fnegate 0e f~ . -1 ok > >> > >> Looks like a bug in SwiftForth's F~ to me. > > > >That's what's notorious about F~ not everyone agrees. > > Have you reported a bug to Forth, Inc., and they disagreed? I didn't claim they had a bug. > >As demonstrated SwitfForth produces the following > > > >> 0e fs. 0.0000000E+00 ok > >> 0e fnegate fs. 0.0000000E+00 ok > > So? I don't think that there is a requirement for FS. or other > FP-printing words to output a minus sign when printing a negative 0. SWF does not claim to support -ve zero. > >If a system cannot *display* -ve zero then for all practical purposes it doesn't > >exist, irrespective of the capabilities of the underlying hardware. As far as the > >SwitfForth end-user is concerned the "encodings" produce the same result > >in every situation and therefore F~ should return a match. > > Except that the specification of F~ specifically refers to the bit > pattern, F~ refers to 'different encodings' for +0e and -0e for systems that support these two. SWF F/P only supports one.
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fatan2 2012 "HAA" <someone@microsoft.com> - 2016-08-22 13:44 +1000
Re: fatan2 2012 Paul Rubin <no.email@nospam.invalid> - 2016-08-21 21:01 -0700
Re: fatan2 2012 peter.m.falth@gmail.com - 2016-08-22 00:42 -0700
Re: fatan2 2012 anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-22 10:00 +0000
Re: fatan2 2012 "HAA" <someone@microsoft.com> - 2016-08-23 12:51 +1000
Re: fatan2 2012 anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-23 11:11 +0000
Re: fatan2 2012 "HAA" <someone@microsoft.com> - 2016-08-25 02:16 +1000
Re: fatan2 2012 albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-09-02 18:03 +0200
Re: fatan2 2012 Paul Rubin <no.email@nospam.invalid> - 2016-09-02 12:02 -0700
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