Re: RPGILE V4.3 Gotcha

Perhaps we need to be more specific in the ILE RPG Reference manual about
how %DEC works.  In particular, the final arithmetic operation within the
%DEC parameter expression is a multiplication by variable DTIQNS.  Since
we know that BIF %DEC results in a decimal (15,3) value, the compiler
takes a little shortcut and performs the multiplication operation with
that precision.  We did it this way to maximize the precision of the
arithmetic results.  After all, it's a lot easier for a programmer to
reduce excess precision than to recover lost precision.

If you really want zero digits of precision in the result, you should use
%DEC(expr:size:0).

Cheers!  Hans


Frank wrote:
>We recompile an ILE RPGIV pgm after doing a mod and got some strange results.
>The following code illustrates the problem. Its compilable and if u debug it
>and check the results u will see they are different when u would expect them
>to be the same.
>The BIF %DEC is the reason.
>D DAABE           S             15  3 DIM(99)
> *
>C                   Z-ADD     5.000         RCDNC1           11 3
>C                   Z-ADD     0.000         RCDNC2           11 3
>C                   Z-ADD     2.5900        DTITRD           15 4
>C                   Z-ADD     144.000       DTIQNS           11 3
>C                   Z-ADD     1             DTITRM           11 4
>C                   CLEAR                   DAABE
>C
>C
> *
>C                   EVAL(H)   DAABE(05) = RCDNC1 / 100 * DTITRD * DTIQNS
>C                   EVAL(H)   DAABE(06) = (RCDNC1+RCDNC2) / 100 * DTITRD
>C                                           * DTIQNS
> *
>C                   EVAL(H)   DAABE(07) = RCDNC1 / 100.00 * DTITRD * DTIQNS
>C                   EVAL(H)   DAABE(08) = (RCDNC1+RCDNC2) / 100.00 * DTITRD
>C                                           * DTIQNS
> *
>C                   EVAL(H)   DAABE(09) = %DEC((RCDNC1 / 100.000
>C                                   * DTITRD * DTIQNS) : 15 : 3)
>C                   EVAL(H)   DAABE(10) = %DEC(((RCDNC1+RCDNC2) / 100.000
>C                                   * DTITRD * DTIQNS) :15 :3)
> *
> *
>C                   SETON                                        LR

Hans Boldt, ILE RPG Development, IBM Toronto Lab, boldt@ca.ibm.com


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