Question

Complete the corresponding assembly language fragments by selecting the correct instruction, register, or value: (Choices in bold)

a) Consider the following fragment of C code:

if(a == b) {

       x += 10;

       A[50] = A[50] +x;

}

else {

        y += 10;

        A[50] = A[50] + y;

}

Assume that variables a, b, x and y are assigned to $s0, $s1, $s2 and $s3 respectively and the base address for array A is in $s4. Only register $t0 is used for storing results temporarily.

bne $s0, ($s0 / $s1 / $s2 / $s3 / $s4 / $t0), else

addi $s2, $s2, 10

lw $t0, (0 / 10 / 50 / 200 / $s1 / $t0) ($s4)

add $t0, $t0, $s2

sw $t0, 200($s4)

j Exit

else: addi $s3, $s3, (0 / 10 / 50 / 200 / $s1 / $t0)

lw $t0, 200($s4)

add $t0, 200($s4)

add $t0, $t0, ($s0 / $s1 / $s2 / $s3 / $s4 / $t0)

(beq / bne / j / add / addi / sll / lw / sw) $t0, 200($s4)

Exit:

b) Consider the following fragment of C code:

while (A[i] == 0) {

       A[i] = A[i] + 10;

       i += 1;

}

Assume that variable i is assigned to $s0 and the base address for array A is in $s1. A is an array of words. Registers $t0 and $t1 are used for storing results temporarily.

Loop: sll $t0, $s0, (0 / 1 / 2 / 4 / 10)

add $t0, $t0, $s1

lw $t1, 0( ($s0 / $s1 / $t0 / $t1 / $zero) )

bne $t1, $zero, (Loop / Exit)

addi $t1, ($s0 / $s1 / $t0 / $t1 / $zero), 10

sw $t1, 0($t0)

addi ($s0 / $s1 / $t0 / $t1 / $zero), $s0, 1

j Loop

Exit;

Answer 1

The answer for the above mentioned question is explained below ::

Explanation is as follows ::