Can we use MVC instruction to move pack field to pack
field....which instruction you will use and why ?
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Answer / steve holton
Qualification to above answer:
You can use MVC to move ANY data from any addressable
storage area to another. So the answer above is correct.
But if you use this technique, it is up to the programmer to
ensure that the result is valid. For example, the source
field may not be the same length as the target, so any
subsequent decimal arithmetic calculations (after a
"straight" MVC FIELD2,FIELD2) against the target field could
result in abend (S0C7). Even if the source field IS packed
decimal, if it is of a different length than the target, the
programmer will have to "adjust" the source and target
specifications to ensure that the result in the target field
is valid packed decimal. For example, if the source field is
PL3 (packed length 3)and the target is PL5, a "straight" MVC
PL5field,PL3field will leave 2 bytes of "garbage" in the
last 2 bytes of PL5field (assuming that you don't get an
abend S0C4 because the and of PL3 is at a page boundary).
For this case to work, you need MVC PL5field+2(3),PL5field,
then you need to ensure that the "top two" bytes of PL5field
are zero to ensure that subesequent packed decimal
arithmetic using PL5field will work.
| Is This Answer Correct ? | 14 Yes | 0 No |
Answer / steve holton
Slight correction to above:
..."you need MVC PL5field+2(3),PL5field,..."
should read:
"you need MVC PL5field+2(3),PL3field,"
Sorry for the typo...
| Is This Answer Correct ? | 9 Yes | 1 No |
Answer / rich hornak
MVC Will work but as explained you must compensate for different lengths.
The more practical instruction would be the ZAP Zero and Add Packed.
The ZAP will adjust for different lengths and propagate leading zeros when a smaller field is being moved to a larger field.
TOTAMT DC PL5'0'
NEWAMT DC PL3'0'
Current Value of TOTAMT X'453789225C'
Current Value of NEWAMT X'00100C'
ZAP Instruction
ZAP TOTAMT,NEWAMT
New Value of TOTAMT After ZAP
TOTAMT DC PL5'000000100C'
| Is This Answer Correct ? | 7 Yes | 0 No |
Answer / nsugandhi
We can certainly use the MVC instruction to move the pack data to another pack field.
| Is This Answer Correct ? | 4 Yes | 0 No |
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COBOL 
