#**********************************************************************
#   CSSE 232: Computer Architecture I
#
#   File:    p7.asm
#   Written by:  J.P. Mellor, 6 Sep. 2004
#
# This file contains a MIPS assembly language program that uses only the
# instructions introduced in p1.asm, p2.asm, p3.asm, p4.asm and p5.asm.
#
# It also takes advantage of several spim syscalls and the assembly
# directive .asciiz
#
#**********************************************************************

	.globl	main
	.globl	V
	.globl	N


	.data

V:	.word   20, 56, -90, 37, -2, 30, 10, -66, -4, 18
N:	.word	10
message1:  .asciiz "The input array:\n"
message2:  .asciiz "The sorted array:\n"
sep:	.asciiz " "
newline:	.asciiz "\n"

#**********************************************************************

	.text

main:	

	sub	$sp, $sp, 8	# Create a 2-word frame.
	sw	$ra, 4($sp)	# Save $ra


#----------------------------------------------------------------------
# 	Print the unsorted array
#----------------------------------------------------------------------

	li	$a0, 10		# pass the length of V
	la	$a1, V		# pass address of V
	la	$a2, message1	# pass address of message1
	jal	print		# call print


#----------------------------------------------------------------------
# 	Sort the array by repeatedly calling SwapMaxWithLast
#----------------------------------------------------------------------

#
# Insert your code here
#

	
#----------------------------------------------------------------------
# 	Print the sorted array
#----------------------------------------------------------------------

	li	$a0, 10		# pass the length of V
	la	$a1, V		# pass address of V
	la	$a2, message2	# pass address of message2
	jal	print		# call print

	
# ---------------------------------------------------------------------
#   Exit the main procedure.
# ---------------------------------------------------------------------

ExitMain:
	lw	$ra, 4($sp)	# Restore $ra
	add	$sp, $sp, 8	# Undo the 2-word frame.
	jr	$ra		# Return





    .globl print

# ---------------------------------------------------------------------
#   Procedure: print
#
#   No frame, none is needed.
#
#   Arguments:
#     $a0 = number of elements in V
#     $a1 = pointer to V
#     $a2 = pointer to message
#
#   Returns:
#     none
#
#   Register allocations:
#     none:
#
#   Prints the array.
# ---------------------------------------------------------------------

print:

#----------------------------------------------------------------------
# 	Save arguments
#----------------------------------------------------------------------
	
	move	$t0, $a1	# initialize the ptr (start of array)
	sll	$t1, $a0, 2	# index*4
	add	$t1, $t1, $t0	# ptr + index*4 = end address

#----------------------------------------------------------------------
# 	Print prompt
#----------------------------------------------------------------------

	move	$a0, $a2	# store pointer to message
	li	$v0, 4		# use system call to
	syscall			# print message

#----------------------------------------------------------------------
# 	Print array
#----------------------------------------------------------------------

loop2:	lw	$a0, 0($t0)	# store next element
	li	$v0, 1		# use system call to
	syscall			# print the min
	la	$a0, sep	# store pointer to sep
	li	$v0, 4		# use system call to
	syscall			# print sep
	add	$t0, $t0, 4	# increment the index
	bne	$t0, $t1, loop2	# check if we've printed all the elements

#----------------------------------------------------------------------
# 	Print final return
#----------------------------------------------------------------------

	la	$a0, newline	# store pointer to a new line
	li 	$v0, 4		# use system call to
	syscall			# print new line

# ---------------------------------------------------------------------
#   Exit to the main procedure.
# ---------------------------------------------------------------------

	jr	$ra		# Return


	.globl SwapMaxWithLast

# ---------------------------------------------------------------------
#   Procedure: SwapMaxWithLast
#
#   No frame, none is needed.
#
#   Arguments:
#     $a0 = address of the array
#     $a1 = number of elements in the array
#
#   Returns:
#     none
#
#   Register allocations:
#     none:
#
#   Swaps the maximum element with the last element of the array.
# ---------------------------------------------------------------------


SwapMaxWithLast:

#
# Insert your code here
#