UofT-CSC258-Computer-Organization/lab10b.s at main · cedricni/UofT-CSC258-Computer-Organization · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
# func1.s
.data
before: .asciiz "Before function\n"
resAdd: .asciiz "A + B is: "
resSub: .asciiz "A - B is: "
newline: .asciiz "\n"

.text
main:
	li $t0, 5	# hard coded value for A
	li $t1, 3	# hard coded value for B

	li $v0, 4 	# system call code for print_string
	la $a0, before 	# address of string to print
	syscall 	# print the string

	li $v0, 4 	# system call code for print_string
	la $a0, resAdd 	# address of string to print
	syscall 	# print the string

	# TODO: setup the arguments for function call doAdd
	move $a0, $t0
	move $a1, $t1

	jal doAdd 	# Make a function call to doAdd()
	#TODO: what exactly does jal do? Lookup the reference sheet

	# TODO: print the return value of doAdd
	move $t2, $v0

	li $v0, 1
	move $a0, $t2
	syscall

	li $v0, 4 	# system call code for print_string
	la $a0, newline # address of string to print
	syscall 	# print the string

	li $v0, 4 	# system call code for print_string
	la $a0, resSub 	# address of string to print
	syscall 	# print the string

	# TODO: setup the arguments for function call doSub
	move $a0, $t0
	move $a1, $t1

	jal doSub 	# Make a function call to doSub()

	# TODO: print the return value of doSub
	move $t2, $v0

	li $v0, 1
	move $a0, $t2
	syscall

	li $v0, 4 	# system call code for print_string
	la $a0, newline # address of string to print
	syscall 	# print the string

	# End of main, make a syscall to "exit"
	li $v0, 10 	# system call code for exit
	syscall 	# terminate program

# start of function doAdd()
doAdd:
	add $v0, $a0, $a1
	# TODO: what need to be done here?
	jr $ra
# start of function doSub()
doSub:
 	sub $v0, $a0, $a1
	# TODO: what need to be done here?
	jr $ra