I would like to understand for the clarity of this discussion what you
mean by unsigned packed decimal data;
is it simply pic 9(8) comp-3, where the internal representation has a
sign nibble which should be always positive,
or is it (as often present in reality) a CHAR field containing decimal
digits WITHOUT a sign nibble which neads byte twiddling
to convert this to a usable number (which is TRUE UNSIGNED ... at least
IMHO)?
Thanks, have a nice day
Bernd
Am 02.05.2025 um 14:30 schrieb Seymour J Metz:
That's the right answer to the wrong question. OP asked about the generated
code, not about the requirements of specific instructions. Lots of applications
deal with unsigned packed decimal, and, yes, it requires more instructions than
signed packed decimal.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
עַם יִשְׂרָאֵל חַי
נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר
________________________________________
From: IBM Mainframe Discussion List on behalf of Robin Vowels
Sent: Friday, May 2, 2025 7:34 AM
To: [email protected]
Subject: Re: Packed decimal sign nibbles
External Message: Use Caution
On 2025-05-02 18:45, Andrew Rowley wrote:
On 2/05/2025 1:22 pm, Tom Ross wrote:
Hmm, if you don't want a sign, why have an 'S' in the PICTURE clause?
Signed:
05 SIGNED-ITEM PIC S9(x) COMP-3.
Unsigned:
05 UNSIGNED-ITEM PIC 9(x) COMP-3.
I guess I am too close to COBOL, but signed and unsigned are easy in
COBOL!
What's the difference in the representation?
Is unsigned 1234:
0x01234F
or
0x001234
To be handled by the hardware, the least-significant nibble
must contain the sign.
Unsigned would contain a plus sign in this nibble.
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