Farley, Peter x23353 wrote:
I am failing to understand something about the code generation that the
Enterprise COBOL compiler (V3.4.1) performs. For a WORKING-STORAGE
variable defined like this:
77 WORK-WORD9 PIC S9(09) BINARY.
with TRUNC(BIN) and OPTIMIZE(STD) in effect, this IF statement:
IF (WORK-WORD9 < -1) OR (WORK-WORD9 > +256)
Generates a bunch of code to convert WORK-WORD9 to packed decimal in
temporary storage (and it does it *twice* no less!) to then do
compare-packed for each of the literal values.
How or why is it that the compiler does not just use binary constants
for such a pair of comparisons? It just does not make any sense to me
for the compiler to convert a fullword binary variable to packed in this
case, and to do it twice for goodness sake. And secondly, if it really
*has* to do the conversion, doesn't the optimizer realize it already did
it already?
The description of OPTIMIZE(FULL) doesn't sound like it will help here,
though I will try it. OPTIMIZE(FULL) says it eliminates unreferenced
WORKING-STORAGE but says nothing about better code optimization.
Confused,
Peter
Peter,
I can't speak with authority, since the details are hidden and,
to some degree, proprietary. But I once learned that when working
with pic s9(9) binary data, the compiler converts to packed to
avoid or intercept overflows. The simplest fix / workaround is to
declare these fields as s9(8) binary. Give that a try and see if
it works better.
Kind regards,
-Steve Comstock
The Trainer's Friend, Inc.
303-393-8716
http://www.trainersfriend.com
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