Question

How do i convert the following C program into MIPS assembly?

int main(void)
{
  int var1[4] ={4, 7, 12, 5};
  int var2[4]= {15, 3, 6, 14};
  int result[4]={0};
 
  for (int i=0 ; i< 4; i++)
    result[i] = var1[i] - var2[i];
 
}

Answer 1

# int var1[4] ={4, 7, 12, 5};
# int var2[4]= {15, 3, 6, 14};
# int result[4]={0};
#
# for (int i=0 ; i< 4; i++)
#   result[i] = var1[i] - var2[i];


.data
   var1:  .word 4, 7, 12, 5
   var2:  .word 15, 3, 6, 14
   result:    .word 0, 0, 0, 0

.text
   la $s0, var1
   la $s1, var2
   la $s2, result

   li $t0, 0  # i = 0
   for:   bge $t0, 4, end

      sll $t1, $t0, 2
      add $t1, $s0, $t1
      lw  $t1, 0($t1)       # $t1 = var1[i]

      sll $t2, $t0, 2
      add $t2, $s1, $t2
      lw  $t2, 0($t2)       # $t1 = var2[i]

      add $t1, $t1, $t2  # $t1 = var1[i] - var2[i]

      sll $t3, $t0, 2
      add $t3, $s2, $t3
      sw  $t1, 0($t3)       # result[i] = var1[i] - var2[i]

      addi $t0, $t0, 1   # i++
      j for
   end: