seltask2.asm

# Data Segment
	.data
input:	.asciiz "Input numbers\n"
msg_a:	.asciiz "a: "
msg_b:	.asciiz "b: "
vline:	.asciiz "|"
minus:	.asciiz "-"
plus:	.asciiz "+"
index:	.asciiz "a\b"
space:	.asciiz " "
nl:		.asciiz "\n"

# Text Segment
	.text
	.globl main

# $s0: a
# $s1: b
# $s2: length of a*b
# $s3: length of a
# $s4: length of b
# $s5: width
# $s6: index_space
# $t0: tmp
# $t0: for calc : a
# $t1: for calc : b

printNum:
	# a0: num
	# a1: length
	# t9: num of space
	# t8: num length
	# t7: backup num

	move $t9, $a1
	move $t7, $a0
	### $t8 = getLength($a0)
	# set argument
	move $a0, $a0
	# call func
	addi $sp, $sp, -4
	sw $ra, 0($sp)
	jal getLength
	lw $ra, 0($sp)
	addi $sp, $sp, 4
	# store value
	move $t8, $v0

	# $t9 = $a1 - $t8
	sub $t9, $a1, $t8

	# store $a0
	addi $sp, $sp, -4
	sw $a0, 0($sp)

	# print space
	li $v0, 4
	la $a0, space
	blez $t9, printNum_break

	printNum_loop:
		syscall
		addi $t9, $t9, -1
		bgtz $t9, printNum_loop

	printNum_break:

	# print num
	li $v0, 1
	move $a0, $t7
	syscall

	# restore $a0
	lw $a0, 0($sp)
	addi $sp, $sp, 4

	jr $ra


getLength:
	# t9: for calc
	# t8: ten
	# a0: num
	# v0: length of num

	# init
	move $t9, $a0
	li $t8, 10
	li $v0, 0
	loop_getLength:
		div $t9, $t9, $t8
		addi $v0, $v0, 1
		bgtz $t9, loop_getLength

	jr $ra


printFrame:
	# no arguments
	addi $sp, $sp, -4
	sw $a0, 0($sp)

	li $v0, 4
	la $a0, plus
	syscall

	move $t0, $s6
	main_indexframe:
		la $a0, minus
		syscall
		addi $t0, $t0, -1
		bgtz $t0, main_indexframe

	la $a0, plus
	syscall

	move $t1, $s5
	addi $t1, $t1, -3
	sub $t1, $t1, $s6
	main_printframe:
		la $a0, minus
		syscall
		addi $t1, $t1, -1
		bgtz $t1, main_printframe

	la $a0, plus
	syscall
	la $a0, nl
	syscall

	# restore \$a0
	lw $a0, 0($sp)
	addi $sp, $sp, 4

	jr $ra


main:
	# print inputmsg
	li $v0, 4
	la $a0, input
	syscall

	# input a, b to $t0, $t1
	li $v0, 4
	la $a0, msg_a
	syscall
	li $v0, 5
	syscall
	move $s0, $v0

	li $v0, 4
	la $a0, msg_b
	syscall
	li $v0, 5
	syscall
	move $s1, $v0

	mul $t0, $s0, $s1 # $t0 = a * b

	### $s2 = getLength(a * b) ###
	# set argument
	move $a0, $t0
	# call func
	addi $sp, $sp, -4
	sw $ra, 0($sp)
	jal getLength
	lw $ra, 0($sp)
	addi $sp, $sp, 4
	# store value
	move $s2, $v0

	### $s3 = getLength(a) ###
	# set argument
	move $a0, $s0
	# call func
	addi $sp, $sp, -4
	sw $ra, 0($sp)
	jal getLength
	lw $ra, 0($sp)
	addi $sp, $sp, 4
	# store value
	move $s3, $v0

	### $s4 = getLength(b) ###
	# set argument
	move $a0, $s1
	# call func
	addi $sp, $sp, -4
	sw $ra, 0($sp)
	jal getLength
	lw $ra, 0($sp)
	addi $sp, $sp, 4
	# store value
	move $s4, $v0

	### index_space($s6) = max($s6, $s3) ###
	li $t0, 3 # for compare
	li $s6, 3
	bgt $t0, $s3, index_space
	move $s6, $s3
	index_space:

	### width($s5) = 1+$s6+1+($s2+1)*b ###
	li $s5, 0
	li $t0, 0
	addi $t0, $s2, 1
	mul $t0, $t0, $s1
	add $s5, $t0, $s6
	addi $s5, $s5, 2

	# call printFrame
	addi $sp, $sp, -4
	sw $ra, 0($ra)
	jal printFrame
	lw $ra, 0($sp)
	addi $sp, $sp, 4

	### printf("|a\\b|"); for(int i=1; i<=b; i++) {printf("%*d|", $s2, i);} printf("\n"); ###
	li $v0, 4
	la $a0, vline
	syscall
	move $t1, $s6
	addi $t1, $t1, -3
	blez $t1, main_noexpand
	main_indexspace:
		li $v0, 4
		la $a0, space
		syscall
		addi $t1, $t1, -1
		bgez $t1, main_indexspace

	main_noexpand:
	la $a0, index
	syscall
	la $a0, vline
	syscall

	li $t3, 1
	main_printindex:
		move $a0, $t3
		move $a1, $s2
		# call func
		addi $sp, $sp, -4
		sw $ra, 0($sp)
		jal printNum
		lw $ra, 0($sp)
		addi $sp, $sp, 4
		li $v0, 4
		la $a0, vline
		syscall
		addi $t3, $t3, 1
		ble $t3, $s1, main_printindex
	
	li $v0, 4
	la $a0, nl
	syscall

	# call printFrame
	addi $sp, $sp, -4
	sw $ra, 0($ra)
	jal printFrame
	lw $ra, 0($sp)
	addi $sp, $sp, 4

	### for (int i = 1; i <= a; i++) {
	### 	printf("|%*d|", $s3, i);
	### 	for (int j = 1; j <= b; j++) {
	### 		printf("%*d|", $s5, j);
	### 	}
	### 	printf("\n");
	### }

	li $t0, 1
main_loop_a:
	li $t1, 1
	li $v0, 4
	la $a0, vline
	syscall

	# set arguments	
	move $a0, $t0
	move $a1, $s6
	# call func
	addi $sp, $sp, -4
	sw $ra, 0($sp)
	jal printNum
	lw $ra, 0($sp)
	addi $sp, $sp, 4

	li $v0, 4
	la $a0, vline
	syscall

	main_loop_b:
		# set arguments	
		mul $t3, $t0, $t1
		move $a0, $t3
		move $a1, $s2
		# call func
		addi $sp, $sp, -4
		sw $ra, 0($sp)
		jal printNum
		lw $ra, 0($sp)
		addi $sp, $sp, 4

		beq $t1, $s1, main_break
		li $v0, 4
		la $a0, space
		syscall

		addi $t1, $t1, 1
		ble $t1, $s1, main_loop_b
	main_break:

	li $v0, 4
	la $a0, vline
	syscall
	la $a0, nl
	syscall

	addi $t0, $t0, 1
	ble $t0, $s0, main_loop_a

	# call printFrame
	addi $sp, $sp, -4
	sw $ra, 0($ra)
	jal printFrame
	lw $ra, 0($sp)
	addi $sp, $sp, 4

	jr $ra