# Chapter 6 Example 9 & 8
#
# pass-by-reference for 1st parameter

# this part adapted from 6.9
	.data
x  :	.word  3	# arbitrary values used to test program for x
y  :	.word  7	# and y
z  : 	.space 4
save2 : .space 4	# saves value during subroutine call
	
	.text
	.globl main    	# declaration of main as a global variable

main:	la $t3, x	# store address of x in t3
	lw $t4, y	# store value of y in t4
	jal strange	# call subroutine strange and save address of next instruction in $31
	sw $t2, z	# save return value of strange in z

# the last 2 lines of main
	li    $v0, 10         # syscall for exit
	syscall               # exit your code 

# end of main 

# this part adapted from 6.8
strange:	sw $t5, save2	# save register t5

		lw $t5, 0($t3)		# store value at $t3 into t5
		mul $t2, $t5, $t4	# z = x * y
		add $t5, $t5, $t4	# x = x + y
		sw $t5, 0($t3)		# store value of t5 into address pointed to be $t3
		
		lw $t5, save2   # restore register t5
		jr $31		# return to caller program at next instruction after subroutine call

# END OF PROGRAM (leave this line here)