Question

Write the following program in MIPS:

a) declare an array A of the following numbers: 3, 5, 8, 10, 12, 2, 76, 43, 90, 44

b) declare a variable called size which stores the number of element in array A, that is 10.

c) write a subroutine to search for a number stored in an array and return true or false. In C++ the subroutine is as follows:
search(array, size, number_To_Search)
e.g. search(A, 10, 12)
The subroutine should return 0 for false or 1 for true in register $v0.

d) The parameters to the search subroutine are stored in $a0=stores base address of A, $a1=stores the number of elements in A that is 10, $a2=stores the number to search for (e.g. 12)
e) In C++, you would write:
  for (int i=0; i<size; i++)
if A[i] == number_to_search return true;
return false

Your MIPS program is a translation of the C++ code.

f) You can test your program by writing the following instructions:
la $a0, A
lw $a1, size
addi $a2, $zero, 12
jal search   # search for 12 in the array A of size 10
lw $a0, $v0   # subroutine search result is store in $v0; its value is moved to $a0
lw $v0, 1    # code to print integer value in $a0
syscall
lw $v0, 10   # code to terminate program
syscall

Answer 1

subroutine in MIPS to search an element is given below:

search(int*, int, int):

        daddiu  $sp,$sp,-48

        sd      $fp,40($sp)

        move    $fp,$sp

        sd      $4,16($fp)

        move    $3,$5

        move    $2,$6

        sll     $3,$3,0

        sw      $3,24($fp)

        sll     $2,$2,0

        sw      $2,28($fp)

        sw      $0,0($fp)

.L5:

        lw      $3,0($fp)

        lw      $2,24($fp)

        slt     $2,$3,$2

        beq     $2,$0,.L2

        nop

        lw      $2,0($fp)

        dsll    $2,$2,2

        ld      $3,16($fp)

        daddu   $2,$3,$2

        lw      $3,0($2)

        lw      $2,28($fp)

        bne     $2,$3,.L3

        nop

        li      $2,1                        # 0x1

        b       .L4

        nop

.L3:

        lw      $2,0($fp)

        addiu   $2,$2,1

        sw      $2,0($fp)

        b       .L5

        nop

.L2:

        move    $2,$0

.L4:

        move    $sp,$fp

        ld      $fp,40($sp)

        daddiu  $sp,$sp,48

        j       $31

        nop

.LC0:

        .word   3

        .word   5

        .word   8

        .word   10

        .word   12

        .word   2

        .word   76

        .word   43

        .word   90

        .word   44

MIPS for declaring array, variable size and calling subroutine search is given below:

ld      $2,%got_page(.LC0)($28)

        daddiu  $3,$2,%got_ofst(.LC0)

        ldl     $3,7($3)

        ldr     $3,%got_ofst(.LC0)($2)

        move    $6,$3

        daddiu  $3,$2,%got_ofst(.LC0)

        ldl     $4,15($3)

        ldr     $4,8($3)

        move    $5,$4

        daddiu  $3,$2,%got_ofst(.LC0)

        ldl     $4,23($3)

        ldr     $4,16($3)

        daddiu  $3,$2,%got_ofst(.LC0)

        ldl     $7,31($3)

        ldr     $7,24($3)

        move    $3,$7

        daddiu  $2,$2,%got_ofst(.LC0)

        ldl     $7,39($2)

        ldr     $7,32($2)

        move    $2,$7

        sd      $6,8($fp)

        sd      $5,16($fp)

        sd      $4,24($fp)

        sd      $3,32($fp)

        sd      $2,40($fp)

        li      $2,10                 # 0xa

        sw      $2,0($fp)

        lw      $3,0($fp)

        daddiu  $2,$fp,8

        li      $6,12                 # 0xc

        move    $5,$3

        move    $4,$2

        ld      $2,%got_disp(search(int*, int, int))($28)

        move    $25,$2

        nop

Thank You.