I am analyzing a job failure related to assembler routine.
The assembler routine abends due data over flow with registers.
The concerned code is given below for your kind reference.
Code:
AP 0(0,R2),0(0,R3) ---> here overflow of data occurs
BO DUMP
END EQU *
L R13,SAVEREGS+4
RETURN (14,12),RC=0
DUMP DS 0H
ABEND 0069,DUMP ----> here it fails wit user- bend
Please suggest me solution to overcome this problem.
Thanks,
Nandakumar
registers have nothing to do with the abend
the AP instruction is a SS ( storage to storage ) operation
and the registers are used as standard components of a base+displacement addressing scheme
Code:
AP 0(0,R2),0(0,R3)
I suspect You are hiding something,
usually it does not make any sense to add two one byte packed numbers
statistically You will get an overflow in the....
45% of the cases for positive only operands
24.9% of the cases for mixed sign operands
so it would be fair to describe better the issue and the environment
TITLE 'NRADAR1 - ADDS ELEMENTS OF ONE DIMENSIONALARRAYS'
NRADAR1 START 0
SAVE (14,12)
BALR R12,0
USING *,R12
ST R13,SAVEREGS+4
LA R13,SAVEREGS
LM R2,R6,0(R1)
ICM R2,8,=X'00' CLEAR HIGH ORDER BYTE OF
ICM R3,8,=X'00' EACH TABLE ADDRESS REGISTER
L R4,0(0,R4)
L R6,0(0,R6)
*
* PARAMETER REGISTERS
*
* R2 - ADDRESS OF ARRAY TO WHICH VALUES ARE TO BE ADDED
* R3 - ADDRESS OF ARRAY FROM WHICH VALUES ARE TO BE ADDED
* R4 - NUMBER OF FIRST ELEMENT TO BE ADDED
* R5 - ADDRESS OF NUMBER OF ELEMENTS TO BE ADDED
*
* WORK REGISTERS
*
*
* R7 - LIMITING INDEX VALUE
* R8 - LENGTH CODE MODIFIER
* R10- MULTIPLY REGISTER
* R11- MULTIPLY REGISTER
EJECT
LR R11,R4 ) FIRST ELEMENT NUMBER
A R11,0(0,R5) ) + NUMBER OF ELEMENTS
S R11,=F'2' ) - 2
MR R10,R6 ) X LENGTH
LR R7,R11 ) = LIMITING INDEX VALUE
AR R7,R3
S R4,=F'1'
MR R4,R6 STARTING INDEX VALUE
LR R8,R6
S R8,=F'1' LENGTH CODE MOD.1 ACTUAL LENG
CVD R8,DECIMAL SET LENGTH CODE
MP DECIMAL,=P'17' MODIFIER FOR AP INSTRUCTION
CVB R8,DECIMAL (2 LENGTHS)
AR R2,R4 SET INITIAL ELEMENT ADDRESS
AR R3,R4 SET INITIAL ELEMENT ADDRESS
ADDARRAY EQU *
EX R8,ADD EXECUTE ADD, SUPPLYING LENGTH
BO DUMP DUMP ON OVERFLOW
AR R2,R6 INCREMENT
BXLE R3,R6,ADDARRAY
B END
ADD EQU *
AP 0(0,R2),0(0,R3)
BO DUMP
END EQU *
L R13,SAVEREGS+4
RETURN (14,12),RC=0
DUMP DS 0H
ABEND 0069,DUMP
*
SAVEREGS DS 9D
DS 0D
DECIMAL DS PL8
R0 EQU 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
END
