This sample was assembled and tested on an OS/390 V2.R9 system during May 2002 and on a z/OS V1.R3 system during November 2002. (Note that because the LINK macro passes control to a separate Load Module, two routines are listed.)
NOGEN |
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'EX7C - EXERCISE IN SUBROUTINE LINKAGE - LINK METHOD' |
EX7C |
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*,R15 |
INITIAL BASE REGISTER |
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BEGIN |
START |
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DC |
AL1(8),CL8'EX7C' |
PROGRAM NAME FOR DEBUGGING |
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DS |
0F |
MY SAVE AREA |
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DC |
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PRESAVE |
DC |
AL4(*-*) |
ADDR OF PREVIOUS SAVE AREA |
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NEXTSAVE |
DC |
AL4(*-*) |
ADDR OF NEXT SAVE AREA |
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SREG14 |
DC |
AL4(*-*) |
GENERAL |
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SREG15 |
DC |
AL4(*-*) |
- - - -> PURPOSE |
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SREG0 |
DC |
13AL4(*-*) |
- - - - - - - -> REGISTER SAVE |
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SAVEEND |
DS |
0H |
END OF MY SAVE AREA |
|
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1 | ||||
START |
EQU |
* | ||
R15 |
DUMP INITIAL BASE REGISTER |
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R14,R12,12(R13) |
SAVE THE REGISTERS ON ENTRY. |
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LR |
R12,R15 |
SET UP MY |
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BEGIN,R12 |
- - - -> BASE REGISTER |
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ST |
R13,PRESAVE |
PERFORM SAVE |
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LA |
R15,SAVEAREA |
- - - -> AREA |
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ST |
R15,8(R13) |
- - - - - - - -> CHAINING |
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LR |
R13,R15 |
R13 = ADDR OF MY SAVE AREA. |
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(INDCB,INPUT,OUTDCB,OUTPUT) OPEN THE FILES. |
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* |
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* |
PREPARE TO BUILD A LIST OF NAMES IN OUTAREA. | |||
* |
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LA |
R4,NAMETAB |
R4 = START OF ARRAY. |
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READREC |
INDCB,INAREA |
READ A RECORD |
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* |
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* |
RETRIEVE THE NAMES AND SORT THEM! | |||
* |
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MVC |
0(8,R4),INAREA |
NO - SLOT NAME IN ARRAY, |
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LA |
R4,8(,R4) |
POINT TO NEXT ARRAY SLOT, |
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B |
READREC |
AND REPEAT TILL EXHAUSTED. |
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READDONE |
LINK |
EP=EX7CSUB,PARAM=(NAMETAB) GO SORT LIST |
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MVC |
OUTAREA+1(80),NAMETAB MOVE SORTED LIST TO RECORD, |
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OUTDCB,OUTAREA |
- - - -> AND OUTPUT IT. |
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SPACE |
3 | |||
EXIT |
CLOSE |
(INDCB,,OUTDCB) |
CLOSE BOTH FILES |
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L |
R13,PRESAVE |
R13 = PREVIOUS SAVE AREA ADDR. |
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RETURN |
(14,12),RC=0 |
RESTORE REGISTERS |
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EJECT | SPACE |
1 |
INDCB |
MACRF=GM,EODAD=READDONE,DDNAME=INDD,LRECL=80,DSORG=PS |
INAREA |
DS |
CL80 |
SPACE |
1 |
OUTDCB |
DCB |
MACRF=PM,RECFM=F,LRECL=133,DDNAME=OUTDD,DSORG=PS |
OUTAREA |
DC |
CL133' ' |
SPACE |
1 |
NAMETAB |
DC |
8X'FF' |
FIRST ENTRY - HIGH VALUES |
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DC |
8XL10'FFFFFFFFFFFFFFFF' FURTHER 8 ENTRIES. |
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NAMETABE |
DC |
XL1'FF' |
END OF NAME TABLE. |
SPACE |
1 |
R0 |
0 | |||
R1 |
EQU |
1 | ||
R2 |
EQU |
2 | ||
R3 |
EQU |
3 | ||
R4 |
EQU |
4 | ||
R5 |
EQU |
5 | ||
R6 |
EQU |
6 | ||
R7 |
EQU |
7 | ||
R8 |
EQU |
8 | ||
R9 |
EQU |
9 | ||
R10 |
EQU |
10 | ||
R11 |
EQU |
11 | ||
R12 |
EQU |
12 | ||
R13 |
EQU |
13 | ||
R14 |
EQU |
14 | ||
R15 |
EQU |
15 | ||
The routine invoked by the EX7C Sample follows
NOGEN |
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'EX7CSUB - SUBROUTINE INVOKED BY EX7C' |
EX7CSUB |
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*,R15 |
INITIAL BASE REGISTER |
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BEGIN |
START |
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DC |
AL1(8),CL8'EX7CSUB' |
PROGRAM NAME FOR DEBUGGING |
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DS |
0F |
MY SAVE AREA |
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DC |
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PRESAVE |
DC |
AL4(*-*) |
ADDR OF PREVIOUS SAVE AREA |
|
DC |
AL4(*-*) |
ADDR OF NEXT SAVE AREA |
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DC |
AL4(*-*) |
GENERAL |
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DC |
AL4(*-*) |
- - - -> PURPOSE |
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DC |
13AL4(*-*) |
- - - - - - - -> REGISTER SAVE |
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SAVEEND |
DS |
0H |
END OF MY SAVE AREA |
|
|
1 | START |
EQU |
* |
|
R15 |
DUMP INITIAL BASE REGISTER |
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R14,R12,12(R13) |
SAVE THE REGISTERS ON ENTRY. |
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LR |
R12,R15 |
SET UP MY |
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BEGIN,R12 |
- - - -> BASE REGISTER |
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ST |
R13,PRESAVE |
PERFORM SAVE |
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LA |
R15,SAVEAREA |
- - - -> AREA |
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ST |
R15,8(R13) |
- - - - - - - -> CHAINING |
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LR |
R13,R15 |
R13 = ADDR OF MY SAVE AREA. |
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L |
R2,0(R1) |
R2 = NAME TABLE ADDRESS |
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SORT |
LR |
R4,R2 |
R4 = START OF ARRAY. |
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LA |
R3,8(,R2) |
R3 = START OF ARRAY + 1. |
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TM |
FLAG,SORTED |
ARE NAMES IN ORDER? |
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BO |
INFORM |
YEP - GO TELL ABOUT IT. |
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OI |
FLAG,SORTED |
NO - INDICATE IT IS. |
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SORT1 |
CLI |
0(R4),X'FF' |
END OF ARRAY? |
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BE |
SORT |
YEP - CHECK ALL DONE, |
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CLC |
0(8,R4),0(R3) |
NO - IS FIRST > SECOND? |
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BH |
SWAP |
YEP - SWAP THEM |
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SORT2 |
LA |
R4,8(,R4) |
NO - MOVE TO |
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LA |
R3,8(,R3) |
- - - -> NEXT |
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B |
SORT1 |
- - - - - - - -> PAIR. |
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SWAP |
MVC |
TEMP,0(R4) |
SAVE FIRST NAME, THEN |
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MVC |
0(8,R4),0(R3) |
MOVE SECOND NAME FORWARD, |
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MVC |
0(8,R3),TEMP |
RETURN FIRST NAME TO ARRAY. |
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NI |
FLAG,255-SORTED |
INDICATE NOT SORTED. |
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B |
SORT2 |
GO GET NEXT PAIR. |
SPACE |
1 |
INFORM |
L |
R13,PRESAVE |
R13 = PREVIOUS SAVE AREA ADDR. |
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RETURN |
(14,12),RC=0 |
RESTORE REGISTERS |
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TEMP |
DS |
CL8 |
SWITCH NAME AREA. |
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FLAG |
DC |
X'00' |
SORTED/UNSORTED INDICATOR |
SORTED |
EQU |
X'01' |
INDICATE SORTED. |
R0 |
0 | |||
R1 |
EQU |
1 | ||
R2 |
EQU |
2 | ||
R3 |
EQU |
3 | ||
R4 |
EQU |
4 | ||
R5 |
EQU |
5 | ||
R6 |
EQU |
6 | ||
R7 |
EQU |
7 | ||
R8 |
EQU |
8 | ||
R9 |
EQU |
9 | ||
R10 |
EQU |
10 | ||
R11 |
EQU |
11 | ||
R12 |
EQU |
12 | ||
R13 |
EQU |
13 | ||
R14 |
EQU |
14 | ||
R15 |
EQU |
15 | ||
Copyright © KMS-IT Limited 2002