Question

ASSEMBLY LANGUAGE (Mars MIPS)

Step 1 (3 points) Based on lab6_Factorial.asm create the program lab6_1.asm as follows: in 'main' prompt the user to enter an integer; store it in $t0 . check if the number entered is negative: if it is negative, then print a message saying so and prompt the user again for a number call the procedure named 'Factorial' whose parameter will be the integer read from the user, and which returns the factorial of that number • pass the parameter in a register • prints a message and the value returned by 'Factorial Run your program and make sure it works correctly.

Starting code:

Factorial: #Factorial Recursive function

subu $sp, $sp, 4

sw $ra, 4($sp) # save the return address on stack

beqz $a0, terminate # test for termination

subu $sp, $sp, 4 # do not terminate yet

sw $a0, 4($sp) # save the parameter

sub $a0, $a0, 1 # will call with a smaller argument

jal Factorial

# after the termination condition is reached these lines

# will be executed

lw $t0, 4($sp) # the argument I have saved on stack

mul $v0, $v0, $t0 # do the multiplication

lw $ra, 8($sp) # prepare to return

addu $sp, $sp, 8 # I’ve popped 2 words (an address and

jr $ra # .. an argument)

terminate:

li $v0, 1 # 0! = 1 is the return value

lw $ra, 4($sp) # get the return address

addu $sp, $sp, 4 # adjust the stack pointer

jr $ra # return

Answer 1

Given below is the code for the question. Please do rate the answer if it helped. Thank you.

.data
   input: .asciiz "Enter a number: "
   output: .asciiz "The factorial is "
.text
  
   la $a0, input
   li $v0, 4 #print string
   syscall

   li $v0, 5    #read int
   syscall
   move $t0, $v0

  
   move $a0, $t0 #pass user input into $a0
   jal Factorial
   move $t1, $v0
  
   la $a0, output
   li $v0, 4 #print string
   syscall
  
   move $a0, $t1
   li $v0, 1 #print int
   syscall
  
   li $v0, 10 #exit
   syscall

Factorial: #Factorial Recursive function
subu $sp, $sp, 4
sw $ra, 4($sp) # save the return address on stack
beqz $a0, terminate # test for termination
subu $sp, $sp, 4 # do not terminate yet
sw $a0, 4($sp) # save the parameter
sub $a0, $a0, 1 # will call with a smaller argument
jal Factorial

# after the termination condition is reached these lines
# will be executed
lw $t0, 4($sp) # the argument I have saved on stack
mul $v0, $v0, $t0 # do the multiplication
lw $ra, 8($sp) # prepare to return
addu $sp, $sp, 8 # I’ve popped 2 words (an address and
jr $ra # .. an argument)

terminate:
li $v0, 1 # 0! = 1 is the return value
lw $ra, 4($sp) # get the return address
addu $sp, $sp, 4 # adjust the stack pointer
jr $ra # return

output
Enter a number: 6
The factorial is 720
-- program is finished running --