Write a function called performDivision in ARM assembly lang

Write a function called performDivision in ARM assembly language that performs integer division, that is, it takes two arguments: a dividend from r0 and a divisor from r1 and return the integer quotient and remainder stored in r0 and r1. Use activation record to write the performDivision function.

Solution

The ARM code is as follows: Intially R0 and R1 are used as Dividend and divisor respectively. Then after division operation R0 stores the quotient and R1 stores the remainder.

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PERFORMDIVISION         PUSH    {R2}        ;store R2 Value
                                          MOVS    R2,#0       ;move 0 to R2 for quotient
                                          CMP     R1,#0       ;Compare divisor to 0
                                          BEQ     SETCARRY    ;if divisor = 0 go to SETCARRY
WHILE                              CMP     R0,R1       ;Compare R0 to R1
                                          BLT     ENDWHILE    ;if dividend<Divisor End loop
                                          ADDS    R2,R2,#1    ;Add 1 to quotient
                                          SUBS    R0,R0,R1    ;Dividend - divisor
                                           B       WHILE       ;branch to start of while
ENDWHILE   
                                    MOVS    R0,R2       ;move quotient to R0 and remainder is R1
                                     POP     {R2}        ;revert R2 to value before subroutine
                                     PUSH    {R0,R1}     ;push R0 and R1
                                     MRS     R0,APSR     ; Set C flag to 0
                                    MOVS    R1,#0x20    ; \"\"
                                     BICS    R0,R0,R1    ; \"\"
                                     MSR     APSR,R0     ; \"\"
                                     POP     {R0,R1}     ;revert R0 and R1 to answer
QUITDIV                      BX      LR          ;Go back to program
SETCARRY   
                                     PUSH    {R0,R1}     ;Store R0 and R1
                                     MRS     R0,APSR     ; Set C flag to 1
                                      MOVS    R1,#0x20    ;\"\"
                                      ORRS    R0,R0,R1    ;\"\"
                                      MSR     APSR,R0     ;\"\"
                                      POP     {R0,R1}     ;Revert R0 and R1 to answer
                                      B       QUITDIV     ;Go back to program