# Declare main as a global function .globl main # All program code is placed after the # .text assembler directive .text # The label 'main' represents the starting point main: la $a0, arr # $a0 based address of array li $a1, 1 # $a1 number to be found (checked) - change the value (7) to test li $a2, 6 # $a2 max array index to be checked - change the value (3) to test li $s0, 0 # set counter to 0 jal lookup # hop to lookup function # print out result li $v0, 1 # print_int syscall code = 1 move $a0, $s0 # load integer into $ao syscall j exit # exit out of program # lookup (int arr[], int num, int cnt). # arr[] = 5 2 1 4 6 3 # 1. lookup (arr, 5, 3) -> 0 (the index of ‘5’ in the array) # 2. lookup (arr, 1, 3) -> 2 (the index of ‘1’ in the array) # 3. lookup (arr, 7, 6) -> -1 (‘7’ is not found in the array) # 4. lookup (arr, 4, 3) -> -1 (the last parameter indicates to check only first 3 values in the lookup: addi $t0, $a2, 1 # store one higher value # loop to find index beq $s0, $t0, setoob # jump to oob function if we overrun array # find current array value addi $t1, $s0, 0 # load index into $t1 sll $t1, $t1, 2 # multiply the offset add $t1, $t1, $a0 # add the offset to the base address lw $t2, 0($t1) # get current array value: aka arr[$s0] beq $a1, $t2, setval # check if this is the value we are looking for addi $s0, $s0, 1 # incriment counter j lookup # back to beginning of loop # set value function setval: jr $ra # set out of bounds function setoob: li $s0, -1 # index is oob, set to -1 jr $ra # jump back to ra in main exit: # All memory structures are placed after the # .data assembler directive .data arr: .word 5, 2, 1, 4, 6, 3 # change array to test #arr: .word 5, 2, 1, 4, 6, 3 # change array to test str_found: .asciiz "found" str_not_found: .asciiz "not_found" nl: .asciiz "\n"