Question

Implement the following code using ARM instructions.

//Objective to practice on procedure, push and pop.

int a=3,b=6,c=2,d=5; /* use registers to store values in global variables*/

main {

          checkEvenfun()

           sunFun()

       }

checkEvenfun() {

                            Check if the register have even numbers if odd replace with 0.

                            Push values in stack.

                           }

         sunFun(){

                           Pop from stack find the sum }

Answer 1

MOV R0 , #3 \\ R0 is a register used to store the integer value 3

MOV R1, #6 \\ R1 is a register used to store the integer value 6

MOV R2, #2 \\ R2 is a register used to store the integer value 2

MOV R3, #5 \\ R3 is a register used to store the integer value 5

main:

BL checkEvenfun \\ call checkEvenfun()

BL sunFun \\ call sunFun()

.end \\ close the main ()

checkEvenfun:

   DIV R4 , R0, #2, \\ divide R0 by 2 and strore that value into register R4

CMP R4,#0 \\ Compare the division result is 0

BNE else   

MOV R0,#0 \\ if R0 is not even then replace R0 with value 0

PUSH {R0} \\ Push R0 into stack

  

   DIV R5 , R1, #2, \\ divide R1 by 2 and strore that value into register R5

CMP R5,#0 \\ Compare the division result is 0

BNE else   

MOV R1,#0 \\ if R5 is not even then replace R1 with value 0

PUSH {R0,R1} \\ Push R1 into stack

DIV R6 , R2, #2, \\ divide R2 by 2 and strore that value into register R6

CMP R6,#0 \\ Compare the division result is 0

BNE else   

MOV R2,#0 \\ if R2 is not even then replace R2 with value 0

   PUSH {R0,R1,R2} \\ Push R2 into stack

DIV R7 , R3, #2, \\ divide R3 by 2 and strore that value into register R7

CMP R7,#0 \\ Compare the division result is 0

BNE else   

MOV R3,#0 \\ if R5 is not even then replace R1 with value 0

PUSH {R0,R1,R2,R3} \\ Push R3 into stack

.end // end the checkEvenfunction

sunFun :

MOV R8, #0 // R8 is a register used to store the Sum

POP {R0,R1,R2,R3} \\ using loop each register values add with sum

ADD R8,R8,R3

   POP {R0,R1,R2}

  ADD R8,R8,R2

POP {R0,R1}

  ADD R8,R8,R1

POP {R0,}

  ADD R8,R8,R0

DISPLAY R8

.end