RE: Question about legacy coding style

Another question about "why" (not "what is it doing").

Why use a MOVE opcode when initializing a numeric field as opposed to the
more clearly numeric-only Z-ADD opcode?

The question is motivated towards understanding what the historical bias
was, in terms of choosing MOVE instead of Z-ADD.

Craig Pelkie


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx]
On Behalf Of Jim Franz
Sent: Wednesday, March 23, 2011 8:43 PM
To: RPG programming on the IBM i / System i
Subject: Re: Question about legacy coding style

in S36 code that would be
C U1NU1 MOVE X2DAT X2DAT 6 0

and your probably correct - to define a field & someone felt it must never
be executed...

In the 80's i did one of these in a subroutine executed 1st time into
calcs..

C MOVE *ZEROS X2DAT 6 0
or
C Z-ADD 0 X2DAT 6 0

Jim Franz
----- Original Message -----
From: "Craig Pelkie" <craig@xxxxxxxxxx>
To: <rpg400-l@xxxxxxxxxxxx>
Sent: Wednesday, March 23, 2011 11:20 PM
Subject: Question about legacy coding style

This is in some old code we are looking at:

C U1
CANNU1 MOVE X2DAT X2DAT 6 0

C U1
CANNU1 MOVE X2UDAT X2UDAT 6 0

C U1
CANNU1 MOVE X2TDT2 X2TDT2 6 0

C U1
CANNU1 MOVE X2DDAT X2DDAT 6 0


It looks like an obscure way to define a field.

What was the reasoning behind defining it like this?

Thanks,
Craig Pelkie


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