Writing User Modules › How to Write Procedure Modules › Coding an Assembler procedure module

Coding an Assembler procedure module

The following module adds two numbers and returns the result to the main CA Culprit program.

Procedure Module

CULLUS94 CSECT
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
         STM   R14,R12,12(R13)     SAVE CALLER'S REGISTERS
         BALR  R3,0                ESTABLISH BASE REGISTER
         USING *,R3
         ST    R13,SAVEAREA+4
         LA    R13,SAVEAREA
         ST    R13,SAVEAREA+8
PROCESS  EQU   *
         LM    R4,R6,4(R1)         R4 ─► R6 POINTS TO ARG1 ─► ARG3
         ZAP   0(8,R6),0(8,R4)     ZERO ARG3, ADD ARG1
         AP    0(8,R6),0(8,R5)     ADD ARG2
RETURN   EQU    *
         L     R13,SAVEAREA+4      RESTORE REGISTERS
         LM    R14,R12,12(R13)
         BR    R14
SAVEAREA DS    18F                 SAVE REGISTER AREA
         B     RETURN
         END   CULLUS94