gistfile1.txt

#   This function takes in
#
#   $a0 as max_size
#   $a1 as row
#   $a2 as col
#   $a3 as 1 or -1
#    1 is = A
#   -1 is =B

#   it returns v0 = 0 if validation failed , else it returns 1

validate_and_set_point:

        slt     $t0, $a1 , $a0
        beq     $t0, $zero, validate_point_fail

        slt     $t0, $a2 , $a0
        beq     $t0, $zero, validate_point_fail

        slti    $t0, $a1, 0
        bne     $t0, $zero, validate_point_fail

        slti    $t0, $a2, 0
        bne     $t0, $zero, validate_point_fail

# check if point in table is not already non 0

        mul     $t0, $a0, $a1
        add     $t0, $t0, $a2 # t0 now has index of the element

        mul     $t1, $t0, 4   # t1 = index * 4
        la      $t2, table

        add     $t2, $t2, $t1 # t2 = Table + index*4
        lw      $t3, 0($t2)   # t3 has the value of the index

        bne     $t3, $zero, validate_point_fail

        sw      $a3, 0($t2)

        li      $v0, 1

        j       validate_point_done

validate_point_fail:
        li      $v0, 0

validate_point_done:

        jr      $ra