# CSE 410 Sp09 Homework 2, part III
# strlen function and test program.
# Replace the empty implement of strlen with actual code,
# and modify the main program to print three different strings
# and their calculated lengths using appropriate calls to
# strlen and prstr.

# name:

# Data declarations

	.data 

test: 	.asciiz  "testing, 1, two, III, 100"
	
out1: 	.asciiz "length of string >"
out2: 	.asciiz "< is "
newline: .asciiz "\n"


.globl main
	.text	

# prstr:
# Print a string and an integer (presumably the length of the string)
# and a descriptive message.
# on entry:  $a0 - address of null-terminated string
#            $a1 - integer value
#            $ra - return address

prstr:
	move	$s0, $a0	# save string address in $s0
	move	$s1, $a1	# save number in $s1 (probably not needed)
	la 	$a0, out1	# print "length of string >"
	li	$v0, 4
	syscall
	move	$a0, $s0	# print string argument
	li	$v0, 4
	syscall
	la	$a0, out2	# print "< is "
	li	$v0, 4
	syscall
	move	$a0, $s1	# print number
	li	$v0, 1
	syscall
	la	$a0, newline	# print newline
	li	$v0, 4
	syscall
	
	jr	$ra		# return

	
# strlen:
# Return the length of a null-terminated string
# on entry:	$a0 - address of the string
#		$ra - return address
# on exit:	$v0 - length of the string (excluding the \0 byte at the end)

strlen:
	li	$v0, -1		# REPLACE WITH ACTUAL IMPLEMENTATION
	jr	$ra		

# beginning of main program

main:	

# REPLACE THIS COMMENT AND THE FOLLOWING CODE SO IT COMPUTES THE LENGTH
# OF THREE SEPARATE STRINGS AND PRINTS THE STRINGS AND THEIR
# LENGTHS BY CALLING strlen AND prstr APPROPRIATELY.
	la	$a0, test	# argument to strlen (currently ignored)
	jal	strlen	
	move	$a1, $v0	# print a string and result of strlen
	la	$a0, test
	jal	prstr
	
end:	li $v0, 10		# stop program
	syscall