In this assignment, you will execute and manipulate a simple program written in MIPS assembly language. The code of this program that recursively calculates the Fibonacci number of a given non-negative integer can be found in the file given
.text main: # Prompt user to input non-negative number la $a0,prompt li $v0,4 syscall li $v0,5 #Read the number(n) syscall move $t2,$v0 # n to $t2 # Call function to get fibonnacci #n move $a0,$t2 move $v0,$t2 jal fib #call fib (n) move $t3,$v0 #result is in $t3 # Output message and n la $a0,result #Print F_ li $v0,4 syscall move $a0,$t2 #Print n li $v0,1 syscall la $a0,result2 #Print = li $v0,4 syscall move $a0,$t3 #Print the answer li $v0,1 syscall la $a0,endl #Print '\n' li $v0,4 syscall # End program li $v0,10 syscall fib: # Compute and return fibonacci number beqz $a0,zero #if n=0 return 0 beq $a0,1,one #if n=1 return 1 #Calling fib(n-1) sub $sp,$sp,4 #storing return address on stack sw $ra,0($sp) sub $a0,$a0,1 #n-1 jal fib #fib(n-1) add $a0,$a0,1 lw $ra,0($sp) #restoring return address from stack add $sp,$sp,4 sub $sp,$sp,4 #Push return value to stack sw $v0,0($sp) #Calling fib(n-2) sub $sp,$sp,4 #storing return address on stack sw $ra,0($sp) sub $a0,$a0,2 #n-2 jal fib #fib(n-2) add $a0,$a0,2 lw $ra,0($sp) #restoring return address from stack add $sp,$sp,4 #--------------- lw $s7,0($sp) #Pop return value from stack add $sp,$sp,4 add $v0,$v0,$s7 # f(n - 2)+fib(n-1) jr $ra # decrement/next in stack zero: li $v0,0 jr $ra one: li $v0,1 jr $ra .data prompt: .asciiz "This program calculates Fibonacci sequence with recursive functions.\nEnter a non-negative number: " result: .asciiz "F_" result2: .asciiz " = " endl: .asciiz "\n"