Re: Trouble with assembler subroutines
Posted: Tue Nov 22, 2011 5:09 pmAnyway, do you have any further hints as to how I have my program invoke a subroutine without crashing?
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Trouble with assembler subroutines
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Posted: Tue Nov 22, 2011 5:09 pmRe: Trouble with assembler subroutines
Posted: Tue Nov 22, 2011 5:50 pmSorry, no. This is something you'll have to learn yourself!
Re: Trouble with assembler subroutines
Posted: Tue Nov 22, 2011 5:58 pmThis says you understand the basics. If you have trouble after using BAL and BR, then the issue is not with invocation of the subroutine but somewhere else.What I need to understand is: how shall I start up a simple internal subroutine such that I can call it? To call the subroutine, I invoke BAL
R14,subroutine - with subroutine being a selected name. To return from a subroutine, I code BR R14.
And asking how to get something to run "without crashing" is totally useless -- either you are running the code and getting a specific abend code (in which case you should post the code at a minimum), or you are not running the code and just guessing about crashing.
Re: Trouble with assembler subroutines
Posted: Tue Nov 22, 2011 6:00 pmdid You care to look at the link I provided You with ? looks like not!
quite a bit of info there and additional links.
anyway the quirks of CALLing <subroutines> are clearly explained here
http://publibz.boulder.ibm.com/cgi-bin/ ... 0522045539
quite a bit of info there and additional links.
anyway the quirks of CALLing <subroutines> are clearly explained here
http://publibz.boulder.ibm.com/cgi-bin/ ... 0522045539
Re: Trouble with assembler subroutines
Posted: Wed Nov 23, 2011 2:13 amHello,
Posting "it didn't work" is probably the worst that can be posted when looking for help. We knew it didn't. So, post some specifics.
My guess is that you have done something incorrectly with register usage or have "walked on" some of memory (instructions).
Possibly - if you will invest a bit of time to show us what is wrong.do you have any further hints as to how I have my program invoke a subroutine without crashing?
Posting "it didn't work" is probably the worst that can be posted when looking for help. We knew it didn't. So, post some specifics.
My guess is that you have done something incorrectly with register usage or have "walked on" some of memory (instructions).
Re: Trouble with assembler subroutines
Posted: Wed Nov 23, 2011 6:02 amThere's something interesting. How do you walk on memory?
Re: Trouble with assembler subroutines
Posted: Wed Nov 23, 2011 6:03 amMy stupid gibberish:
LAB6A SUBENTRY
LAB6A CSECT
BALR 12,0
USING *,12
SAVE (14,12)
BALR 12,0
USING *,12Â
LA 2,SAVEAREAÂ
ST 2,8(,13)
ST 13,4(,2)
LR 13,2
LA 1,DATA
LM 14,12,12(13)
OI 15(13),X'01'
LA 15,0(0,0)
BAL 15,SUMRTN
BAL 15,SUMRTN
BAL 15,SUMRTN
LA 3,X'00000000'
LA 4,X'00000001'
LA 5,X'00000063'
ZAP B,=P'0'
ZAP SUM,=P'0'
ZAP A,=P'1'
LOOP DS 0H
AP B,A
AP SUM,B
BXLE 3,4,LOOP
MVC FIELD,MASK
ED FIELD,SUM
WTO MF=(E,WTOMSG)
SUBEXIT
WTOMSG DC AL2(WTOMEND-*,0)
HELLO DC C'THE SUM OF THE NUMBERS FROM 1 TO 100 IS '
FIELD DS CL10
WTOMEND EQU *
*
MASK DC X'40206B2020206B202020'
PRNTLINE DS CL133
SUM DS PL4
B DS PL4
A DS PL4
C DS PL4
CB DS PL4
DB DS PL4
SAVEAREA DS 18F
DATA DC CL5'00800'
SUMRTN DS 0H
WTO 'NONSENSE'
BR 15
ENDPGM DS D
END LAB6A
LAB6A CSECT
BALR 12,0
USING *,12
SAVE (14,12)
BALR 12,0
USING *,12Â
LA 2,SAVEAREAÂ
ST 2,8(,13)
ST 13,4(,2)
LR 13,2
LA 1,DATA
LM 14,12,12(13)
OI 15(13),X'01'
LA 15,0(0,0)
BAL 15,SUMRTN
BAL 15,SUMRTN
BAL 15,SUMRTN
LA 3,X'00000000'
LA 4,X'00000001'
LA 5,X'00000063'
ZAP B,=P'0'
ZAP SUM,=P'0'
ZAP A,=P'1'
LOOP DS 0H
AP B,A
AP SUM,B
BXLE 3,4,LOOP
MVC FIELD,MASK
ED FIELD,SUM
WTO MF=(E,WTOMSG)
SUBEXIT
WTOMSG DC AL2(WTOMEND-*,0)
HELLO DC C'THE SUM OF THE NUMBERS FROM 1 TO 100 IS '
FIELD DS CL10
WTOMEND EQU *
*
MASK DC X'40206B2020206B202020'
PRNTLINE DS CL133
SUM DS PL4
B DS PL4
A DS PL4
C DS PL4
CB DS PL4
DB DS PL4
SAVEAREA DS 18F
DATA DC CL5'00800'
SUMRTN DS 0H
WTO 'NONSENSE'
BR 15
ENDPGM DS D
END LAB6A
Re: Trouble with assembler subroutines
Posted: Wed Nov 23, 2011 7:10 amI can certainly see why your program is crashing. Everything up to the LA 1,DATA is okay -- bizarre from the repeated code, but not causing a crash. The LM 14,12,12(13) destroys everything else you'd done up to that point -- it restores register 1 to the value it had when the operating system turned control over to your program, wipes out register 12 (which is being used as your base register). This makes the rest of your program hazardous since the base displacements are no longer valid since they're using register 12 that just got restored to the original value, not the value the BALR 12,0 put in it.
And since you are so careful to use WTO M=(E,WTOMSG) the first time with a length and all that, why use WTO 'NONSENSE' in the subroutine?
And since you are so careful to use WTO M=(E,WTOMSG) the first time with a length and all that, why use WTO 'NONSENSE' in the subroutine?
Re: Trouble with assembler subroutines
Posted: Wed Nov 23, 2011 7:18 am"Walking on memory" is a phrase to indicate something is altering your program, almost always that "something" is your program.RISCCISCInstSet wrote:There's something interesting. How do you walk on memory?
Re: Trouble with assembler subroutines
Posted: Wed Nov 23, 2011 9:07 amThere are a lot of problems in your code; many more than Mr. Sample indicated. You'll learn more if you figure them out yourself.