RE: [open-cobol-list] Cobol Precision

[Roger While]

OK. Thanks for the info. I overlooked E.16.
Although it is still not clear to me what this reference to 1000 decimal
places is. (wonders if the gmp library would be able to handle that)

Roger

At 19:14 26.05.2005 -0500, you wrote:
> When "ARITHMETIC IS STANDARD" (new in the '02 Standard) is in effect, then
> there are rules (designed) to produce "portable and predictable" results 
> for
> SOME - but not all - arithmetic statements and expressions.
>
> The "SIDI" (Standard Intermediate Data Item) is a "conceptual" data item
> used for intermediate results.  This is a >>>DECIMAL<<< type
> "floating-point" (not Binary, not Hex, not anything like what most people
> are used to today) AND it isn't even a "data-type" that is required to 
> exist
> in COBOL itself (from a user perspective).
>
> Truncation and precision is done in Decimal (not binary) Floating Point.
>
> There is a discussion of all of this - including examples of how this 
> works
> in
>   "E.16 Standard arithmetic"
> starting on page 763 of '02 Standard.
>
>    ****
>
> However, you might also want to look at a proposal included in the current
> revision work for the '08 Standard.  Check out:
>
>   http://www.cobolportal.com/j4/files/05-0047.doc
>
> IEEE is working on creating a "new" decimal floating point data type
> (actually 3 different ones) and these MAY be easier to use in COBOL (as an
> intermediate data type) when/if available on various hardware/software
> platforms.
>
>    ****
>
> Does this actually answer you question?  If not, can you help me 
> understand
> it better?
>
> NOTE WELL:
>   In both the '02 Standard and the draft revision, the DEFAULT remains
> "arithmetic is native" - so the implementor can do anything they want
> (including truncating every operand and intermediate data item to integers
> <G> - although I don't think that would be very popular).
>
> > -----Original Message-----
> > From: address@hidden
> > [mailto:address@hidden On
> > Behalf Of Roger While
> > Sent: Thursday, May 26, 2005 5:37 PM
> > To: Bill Klein
> > Cc: address@hidden
> > Subject: [open-cobol-list] Cobol Precision
> >
> > Clarification required :
> > 8.8.1.3.1.1 Precision and allowable magnitude
> > A standard intermediate data item has the unique value of
> > zero or a value
> > whose magnitude is in the range of
> > 10-999 (1.000 000 000 000 000 000 000 000 000 000 0E-999)
> > through
> > 101000 - 10968 (9.999 999 999 999 999 999 999 999 999 999 9E+999)
> > inclusive, with a precision of 32 decimal digits. A standard
> > intermediate
> > data item shall be truncated or rounded
> > to fewer than 32 digits only as explicitly specified.
> >
> > What exactly does this mean ?