RE: [boost] Formal Review for Interval Library- getting intervals of constants - radix?

From: Paul A. Bristow (boost_at_[hidden])
Date: 2002-09-08 17:12:01

http://researchweb.watson.ibm.com/journal/rd/435/schwarz.html

gives the format of the IBM S/390 binary and hex formats.

Do we need interval constants to cater for these?

These have significands with 24 (23 has hidden signidicand so doesn't
count?)
53 (52 plus hidden bit?)

56 hex

and 56 +56 = 112 hex and 48 + 64 = 112 binary

Does the radix make any difference the exact decimal values?
I don't see how it does, but is anyone more knowldegable?

Paul

Dr Paul A Bristow, hetp Chromatography
Prizet Farmhouse, Kendal, Cumbria, LA8 8AB  UK
[phone]  Mobile [phone]
mailto:pbristow_at_[hidden]

> -----Original Message-----
> From: boost-bounces_at_[hidden]
> [mailto:boost-bounces_at_[hidden]]On Behalf Of Gabriel Dos Reis
> Sent: Saturday, September 07, 2002 1:03 AM
> To: boost_at_[hidden]
> Subject: Re: [boost] Formal Review for Interval Library-
> gettingintervalsofconstants
>
>
> "Paul A. Bristow" <boost_at_[hidden]> writes:
>
> Firstly, thanks for your feedback.
>
> | and long double 64 bit significand formats:
>
> One of my previous points is that it is unwise to assume that just
> because you're using IEEE-754 system means that the long double
> datatype is 80 bits wide.  If you take an IEEE-754 plateform like a
> SPARC, you get a 128 bits.  Some IEEE-754 plateforms use 96 bits.
> That means that a scalable way to tackle the issue it to parameterize
> on the relevant FP system description as given by numeric_limits<>.
>
> [...]
>
> | (Are there really any machines using radix other than 2 that we need to
> | cater for?)
>
> If you have users with some IBM machines with radix = 16, then you'll
> have to add the support.  I know I did use such a system for
> computations a year ago. However, I can't tell you whether I'll use it
> in the near future or not -- I'm not yet graduated in Madame Soleil
> magic :-) :-)
>
> -- Gaby
> _______________________________________________
> Unsubscribe & other changes:
> http://lists.boost.org/mailman/listinfo.cgi/boost
>