Question

• write a program that takes the input value from the user and calculate the sum from that number to zero in MIPS

Answer 1

.text
.global main
main: 
li $v0,4            #print message msg1, code used is 4
la $a0,msg1
syscall
li $v0,5       # to read  N from user, code is 5 and integer stored in $v0
syscall
move $t0,$v0             # $t0=N.if pseudo instruction not works, use addi $t0,$v0,$zero
li $t1,0     #initialize t1=0 , so store sum
loop:    add $t1,$t1,$t0                # To find sum
             li $t3,1                               # $t3=1
            sub $t0,$t0,$t3                   # $t0=$t0-1
            beq $t0,$zer0,exit             # if $t0=0, then goto exit
           j loop                                    # if $t0≠0, repeat the loop
exit:    li  $v0,4                                  #to print messge sum=
            la $a0,msg2
           syscall
           li $v0,1                                 # to print sum stored in $t1
          move $a0,$t1   # if not working, use addi $a0,$t1,$zero
          syscall
         li $v0,10                         #to exit
         syscall
.data
msg1:    .asciiz   “enter the value of N:”
msg2:    .asciiz “sum=”

Note: if move instruction, which is a psedoinstruction in MIPS QTSPIM, use addi instruction as given as comment.