Question

4.Translate the following C code to MIPS assembly code. Assume that the value of i is in register $t0, and $s0 holds the base address of the integer MemArray

if (i > 10)

MemArray[i] = 0;

else

MemArray[i] = -MemArray[i];

6.Translate the following C code to MIPS assembly code. Use a minimum number of instructions. Assume that the values of a, b, i, and j are in registers $s0, $s1, $t0, and $t1, respectively. Also, assume that register $s2 holds the base address of the array D.

for(i=0; i<a; i++)

for(j=0; j<b; j++)

D[j] = i + j;

Answer 1

I considered it as word directive; if any other accordingly offset will change

4)

li $t1, 10
sll $t2, $t0, 2           #offset for i
add $t3, $s0, $t2       #address of MemArray[i]
bgt $t0,$t1,IF_CON       #condition
ELSE:                   #else body
   lw $t4,0($t3)
   sub $t4, $0, $t4   #changing sign
   sw $t4,0($t3)
   j NEXT
IF_CON:                   #if body
   li $t4,0
   sw $t4,0($t3)       #storing zero
NEXT:

6)

li $t0,0               #i=0
OUTER_FOR:
   bge $t0,$s0,EXIT_OUTER_FOR       #outer loop condition
  
   li $t1,0               #j=0
INNER_FOR:  
   bge $t1,$s1,EXIT_INNER_FOR       #outer loop condition
   sll $t2, $t1, 2           #offset for i
   add $t3, $s2, $t2       #address of D[j]
   add $t4, $t0,$t1       # i+j
   sw $t4,0($t3)           # D[j] = i+j
   addi $t1,$t1,1                   #j++
   j INNER_FOR  
EXIT_INNER_FOR:
   addi $t0,$t0,1                   #i++
   j OUTER_FOR
EXIT_OUTER_FOR: