[Cfp-interest 2495] Re: 5.2.4.2.3 and IEC 60559

[Jim Thomas]

> On Aug 3, 2022, at 5:45 PM, Fred J. Tydeman <tydeman at tybor.com> wrote:
> 
> On Wed, 3 Aug 2022 14:19:27 -0700 Jim Thomas wrote:
>> 
>> The decimal floating types are IEC 60559 decimal formats.
>> 
>> The characteristics if 5.2.4.2.3 are given the specific values for IEC 60559 decimal formats, rather than limits as in 5.2.4.2.2.
> 
> It is not clear from 5.2.4.2.3 that they are IEC 60559 DFP.
> There are no forward references to any clause 6 section
> (the ones you mentioned).

5.2.4.2.3 gives the characteristics of the decimal floating types, and requires the characteristics to match those of IEC 60559 decimal formats. Why does 5.2.4.2.3 need forward references to clause 6? If it would be helpful to the reader for 5.2.4.2.3 to say the types are IEC 60559 formats, we could pursue that, though it would add nothing normative.
> 
> The first computer I programmed on in 1967 used decimal floating point (BCD)
> (the IBM 1620).  So, I know of two kinds of DFP.

Maybe the 1620 decimal floating point could be used for C standard floating types, but not for C decimal floating types.

- Jim Thomas
> 
> 
> 
> 
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> Fred J. Tydeman        Tydeman Consulting
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