Question

Convert the following C++ code into MIPS assembely. For testing I will be change the values for q,y,x with few different values.

//q -> $s0
//y -> $s1
//x -> $s2

int main(){
  int q = 5;
  int y = 17;
  int x = 77;
        
  if ( q < 10){
                cout << "inside if";
  } elseif ( x > 0 || y < 10) {
                cout << "inside elseif";
  } else {
                cout << "inside else";
  }
}

Answer 1

Note: Input values, statement data and label names are arbitrary. These can be changed according the user's choice. Please refer to code snippets for a better understanding of comments and indentations.

IDE Used: MARS

Program Code

.data
   if_state : .asciiz "inside if"
   elseif_state : .asciiz "inside elseif"
   else_state : .asciiz "inside else"
  
.text
   # initialise registers
   li $s0, 11
   li $s1, -1
   li $s2, 77
  
   # check if $s0 < 9, if true then branch to
   # if segment
   blt $s0, 9, if_seg
  
   # elseif check $s1 > 0 or $s2 < 10
   # if anyone true then branch to elseif segment
   bgt $s1, 0, elseif_seg
   blt $s2, 10, elseif_seg
  
   # else directly branch to else segment
   else_seg :
       # print else statement
       li $v0, 4
        la $a0, else_state
        syscall  
       
        # end the progrsm
        li $v0, 10
        syscall
   
    # if segment label
    if_seg :
        # print the if statement
        li $v0, 4
        la $a0, if_state
        syscall  
       
        # end the progrsm
        li $v0, 10
        syscall
   
    # elseif segment branch      
    elseif_seg :
        # print the else if statement
        li $v0, 4
        la $a0, elseif_state
        syscall  
       
        # end the progrsm
        li $v0, 10
        syscall  
   
   

Code Snippets

Sample Output Run

for $s0 = 5, $s1 = 17, $s2 = 77

for $s0 = 11, $s1 = -1, $s2 = 5

for $s0 = 11, $s1 = -1, $s2 = 77