HP 3000 Manuals HP 3000 Manuals
Changed Features
This section lists COBOL II/XL features that have changed from COBOL
II/V. For more information on these changes and required program
conversions, refer to the section "Conversion of Changed Features" in
Chapter 3. It describes the changes in the same order as they are listed
here.
1. Index data items are 32 bits (4 bytes) long on MPE XL systems. On
MPE V systems, they are 16 bits (2 bytes) long.
2. On MPE XL systems, data alignment varies according to the position
of the item in the source program. In the WORKING-STORAGE and
FILE sections, level 01, 77, COMP or BINARY SYNCHRONIZED data
items and INDEX data items are aligned on 32-bit boundaries. In
the LINKAGE section, all data items are aligned on 8-bit (byte)
boundaries even if the SYNCHRONIZED clause is specified. On MPE V
systems, data items are aligned on 16-bit boundaries.
3. The format and content of output that the compiler generates as a
result of the $CONTROL MAP, $CONTROL CODE, and $CONTROL VERBS
directives are different on MPE XL systems.
4. COBOL II/XL no longer removes hyphens embedded in literals used on
the PROGRAM-ID paragraph or on the ENTRY and CALL statements. It
changes the hyphens to underscores.
5. COBOL II/XL uses the first 30 characters of external names and
ignores any additional characters. COBOL II/V uses the first 15
characters for subprograms and the first 12 characters for main
programs.
6. All external names (except intrinsics) are converted to lowercase
unless you begin the name with a backslash.
7. The GIVING identifier of the pseudo-intrinsic .LOC. should be
defined either as PIC S9(9) or PIC S9(18) in HP COBOL II/XL
instead of PIC S9(4).
8. The MPE V commands (COBOLII, COBOLIIPREP, COBOLIIGO, COBOL,
COBOLPREP and COBOLGO) do not operate for the COBOL II/XL
compiler. New commands are provided for the COBOL II/XL compiler.
9. All calls to HP system intrinsics, with the exception of
VPLUS/TurboImage CALLS, must include the keyword INTRINSIC in the
CALL statement.
10. The performance when referencing table elements using subscripts
defined as
PIC S9(9) COMP SYNC
is the same as referencing table elements using index items in
COBOL II/XL. In COBOL II/V, performance is improved by referencing
table elements using indexes as opposed to using subscripts. In
COBOL II/XL, indexes and subscripts (as specified above) are
implemented similarly.
11. On MPE V systems, numeric display and packed-decimal data are
checked for validity, by default. On MPE XL systems, no validity
checking of this data takes place, by default. HP COBOL II/XL
programs cannot be expected to execute the same way with illegal
or incompatible data values, that is, when the value of a data
item does not match its picture clause.
12. COBOL II/XL object programs compiled with the $CONTROL VALIDATE
and BOUNDS options abort, by default, when an illegal ASCII or
decimal digit is encountered during a validity check or when
division by zero or an overflow condition occurs and there is no
ON SIZE ERROR clause. Using the $CONTROL options previously
described in "Error Handling Options," you can change the default
action. COBOL II/V attempts to fix the illegal data and if it is
fixable continues the program.
13. Data items described as 32-bit COMP (or BINARY) without the
SYNCHRONIZED clause may or may not be aligned on 32-bit
boundaries. Passing misaligned data items to subprograms that
expect aligned parameters will cause run-time errors.
14. When adding two items defined as S9(18) or S9(9) COMP (or BINARY)
COBOL II/XL may trap with integer overflow unless an ON SIZE ERROR
clause is included. (Refer to "Error Handling Options" in this
chapter for more information on how to handle errors in COBOL
II/XL.)
15. The commercial at sign (@) preceding an identifier in the USING
phrase of the CALL statement is ignored.
16. Uninitialized data items used in calculations have always produced
unpredictable results on MPE V systems and continue to do so on
MPE XL systems.
_________________________________________________________________
NOTE You must initialize all data items used in calculations.
_________________________________________________________________
17. Truncation of BINARY and COMPUTATIONAL result fields (in
arithmetic operations) is different on MPE XL systems.
18. Overlapping table MOVEs initialize only the first element. In the
following example, only the first element of TABLE2 (NUM) is
initialized with the value in the sending field NUM-FIELD.
01 TABLE1.
05 NUM-FIELD PIC S9(9) COMP VALUE ZERO.
05 ALPHA-FIELD PIC X VALUE SPACES.
05 TABLE2.
10 TABLEOCC OCCURS 5 TIMES.
15 NUM PIC S9(9) COMP.
15 ALP PIC X.
.
.
PROCEDURE DIVISION.
.
.
MOVE TABLE1 TO TABLE2.