# A simple program to demonstrate loops, and array accessing
# Written by Scott D. Anderson, 2/2/98

	.text
	.globl main
main:
	nop
	nop

#
# This code corresponds roughly to the following C code:
#  int array = { 16, 32, 64, 128, 256, 512, 1024, 2048 }
#  int x=0xFFFFFFFF
#  x=0;
#  for( int i=0; i<8; i++ ) x += array[i]
#  array[5] = x	
#
	.data
x:	.word 0xFFFFFFFF
Array:	.word 16
	.word 32
	.word 64
	.word 128
	.word 256
	.word 512
	.word 1024
	.word 2048
	.text
	sw $0,x			# initialize x to zero
	add $s0, $0, $0		# Use $s0 as i, initialize it to zero
	addi $s1, $0, 8		# Use $s1 for the upper bound of the loop
				# init it to the constant 8
	add $s2, $0, $0		# Use $s2 for the running sum, init to zero
	la $s3, Array		# Use $s3 as pointer into the array.
loop1:	slt $t0, $s0, $s1	# is i < 8?
	beq $t0, $0, done1	# done if i isn't < 8, when $t0 will be zero
	lw $t1,0($s3)		# get some array data into temporary
	add $s2,$s2,$t1		# add it to running sum
	sw $s2,x		# store into x--is this really necessary?	
	addi $s0,$s0,1		# add 1 to $s0.  
	addi $s3,$s3,4		# add 4 to $s2.  Why 4?
	j loop1
done1:	la $s3, Array		# reload $s3 with address of array
	sw $s2,20($s3)		# why 20?
	sw $0,0x14($s3)		# what does this instruction do?
#
# Done !!!
#
	jr $ra			# Return from main