[ANSI-Smalltalk] Agenda items...

[Andres Valloud]

Does anybody know where to find a viewable copy of ISO/IEC 10967?  I see it
refers to language independent arithmetic...

Andres.

On Nov 14, 2007 3:55 PM, Andres Valloud <andres.valloud at gmail.com> wrote:

> Paolo,
>
> Yes, the implementation here uses 1023 and -1022.  Hmmmm... I am not sure
> about emax / emin being off by one though.  If the range goes from 0 to
> 2047, and 0 and 2047 are taken, then that takes one off from each side, and
> 1024 / -1021 do not balance out that way?...
>
> Andres.
>
>
> On Nov 13, 2007 11:49 PM, Paolo Bonzini <paolo.bonzini at lu.unisi.ch> wrote:
>
> > > fmax
> > >     (1 - (self radix raisedTo: self precision negated))
> > >         * (self radix raisedTo: self emax + 1)
> > >
> > >     Note the ANSI spec says
> > >
> > >     (1 - (self radix raisedTo: self precision negated))
> > >         * (self radix raisedTo: self emax)
> > >
> > > fminDenormalized
> > >     self radix raisedTo: self emin - self precision + 1
> > >
> > >     Note the ANSI spec says
> > >
> > >     self radix raisedTo: self emin - self precision
> >
> > I think you also have emin and emax off by one. :-)  The exponent field
> > goes from 1 to 2046 for Doubles, since 0 is reserved for zero/denormals
> > and 2047 for infinities/NaNs.
> >
> > Since the mantissa in LIA-1 is < 1, emax is 1024 and emin is -1021.  You
> > probably are using 1023 and -1022.
> >
> > Then, if you put precision = 52 in this you do get an off-by-one error,
> > which convinces me more that, as you said, the right value of precision
> > should include the implicit 1.  So, no errata in <FloatCharacterization>
> > right?
> >
> > Paolo
> >
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> >
>
>
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