Question

Prompt user to enter an integer number from console. Use 3 methods to check if this number is even or odd. Display result.

This is required to be done in MIPS assembly language.

Answer 1

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Note : check attached image for output ,code compiled and tested in MARS MIPS simulator.

Program Plan :

1. to read input call getInput function use syscall 4 to prompt string
2. syscall 1 to read integer input and return from function
3. now call checkEvenOdd function if num is odd it will return 0 else 1
4. call display result to print number is odd/even .
5. terminate program .

Program :

.data
   even:    .asciiz "Number is even.\n"
   odd:    .asciiz "Number is odd.\n"
   prompt: .asciiz "Enter number : "
  
  
.text
   main:
       #call method to get input from user
       #user input from return from function stored in $v0
       jal getInput
       #$a0 is argument register
      
       addi $a0,$v0,0 #move user input($v0) in $a0
       #pass user input to function checkEvenOdd
       #if value is even it will 1 else return 0
       #return value in $v0
       jal checkEvenOdd
       #move return value in $a0
       addi $a0,$v0,0
       #call displayResult to print number is even or odd
       jal displayResult
      
       #terminate program using syscall 10
       li $v0,10
       syscall
      
      
#method getInput       
getInput:
   la $a0,prompt #load address of prompt string in $a0 register
   li $v0,4 #syscall 4 to print string
   syscall
  
   #read input stored in $v0
   li $v0,5
   syscall
   #return to address save in $ra (address of code section from it called)
   jr $ra

#function to check user input odd or even
checkEvenOdd:
   li $t0,2 #load 2 in $t0 register
   div $a0,$t0 #divide user input $a0 by 2($a0) and result stored in lo(quotient) and hi(reminder) register
  
   mfhi $t0 #store reminder of above divide in $t0
  
   seq $v0,$t0,0 #if $t0==0 set 1 to $v0 else set 0 to $v0
  
   jr $ra #return value of $v0 and go to addres from it called
  
#function displayResult to print result  
displayResult:
   #if argument $a0 is 0 than jump to printOdd label else go to next line print even
   beq $a0,0,printOdd
   la $a0,even #load address of even in $a0
   li $v0,4 #syscall 4 to print string
   syscall
   j return #jump to return label
    printOdd: #print odd label
       la $a0,odd #load address of odd string
       la $v0,4 #syscall 4 to print string
       syscall
      
    return: #return label
       jr $ra  
  
      
  
  

Output :   

Please comment if you want any changes . up vote ,