RE: Making sense of 4-byte binary fields

["Bob Cozzi" <cozzi@xxxxxxxxx>]

4-byte binary fields are a convention for identifying the "integer" data
type. It is NOT referring to the old RPGIII Binary fields. And I don't buy
the "4B" argument:
0085.00 D                 DS 
0086.00 D  MSGDLN                 1      4B 
0087.00 D  MSGDLN2                5      8B 0

Once you get passed the first subfield, the 4B identity is gone.

The RPG binary fields ("B" data types) are 100 to 1000 times slower than the
I (integer) data types. This gives me reason enough to avoid them. In
addition the overhead that causes this slowness is due to the system
converting the binary data into packed decimal (under the covers) and then
back again.
A poor design decision on IBM's part was in requiring the Integer data type
to be coded as 3I, 5I, 10I or 20I is the root of the problem. It should have
been 1I, 2I, 4I, and 8I.  IBM could add this capability without impacting
existing code--and it would make things much easier to comprehend by those
still using the "B" data type. 

Using a "B" data type today when calling an API is exactly the same kind of
code as this:
     C   25              DO        6
     C                   Add       1             Counter
     C                   Enddo          

In other words, it is on par with conditioning indicators used with
structured operation codes.


-Bob Cozzi


-----Original Message-----
From: rpg400-l-bounces+cozzi=rpgiv.com@xxxxxxxxxxxx
[mailto:rpg400-l-bounces+cozzi=rpgiv.com@xxxxxxxxxxxx] On Behalf Of
MWaite@xxxxxxxxxxxx
Sent: Wednesday, March 09, 2005 10:42 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: Making sense of 4-byte binary fields

I may be going against the grain here, but if the documentation says 
4-byte binary I just specify 4-byte binary in my code, as shown below, 
which works just fine, and the way we always used to define binary fields 
prior to RPGIV.

0085.00 D                 DS 
0086.00 D  MSGDLN                 1      4B 0 

The problem lies if you code the field using the new sexy type 'S' for a 
standalone field, when you only get the opportunity to specify the number 
of DIGITS, rather than bytes.

So, keep your 4Bs, but remember to code the field as part of a data 
structure, not a standlone field. This way, the numbers do appear to make 
sense!(And we don't need to know that the machine can get 10 digits in 4 
bytes!)

Hope this provides some illumination...



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