#This program demonstrates math operations in MIPS.
#author: Hornick
#CS2710 - 1/5/2013

.text	#.text directive (default) just tells the assembler where to put the instructions in memory

main:	#this label is assigned the value of the address of the next instruction
	addi    $t1, $zero, 0x7FFFFFFF  # largest positive signed int
	addi	$t2, $zero, 1	# t2=1

#signed/unsigned addition	
	addu	$t3, $t2, $t1	# unsigned addition; no exception generated on overflow
#	add	$t3, $t2, $t1   # signed addition; exception generated (when sign of result is opposite that of operands)

#integer multiplication
	addi	$t1, $zero, 0x7FFFFFFF # largest positive signed int
	addi	$t2, $zero, 32	# t2=32
	mult	$t1, $t2	# 64-bit product in $hi/$lo registers
	mul	$s3, $t1, $t2	# most significant bits in $hi;
				# least significant 32-bits in $lo and $s3
	mfhi	$s0		# move 32-bit $hi to $s0
	mflo	$s1		# move 32-bit $lo to $s1
	
#integer division with finite operands
	addi	$t1, $zero, 17	# t1=17
	addi	$t2, $zero, 5	# t2=5
	div	$t2, $t1	# 5/17, quotient (0) in $lo, remainder (5) in $hi
	div	$t1, $t2	# 17/5, quotient (3) in $lo, remainder (2) in $hi

#integer division with 0 operands
	addi	$t1, $zero, 0	# t1=0
	addi	$t2, $zero, 5	# t2=5
	div	$t2, $t1	# 5/0, error (programmer must check for 0 denominator) - no change to $hi or $lo
	div	$t1, $t2	# 0/5, quotient (0) in $lo, remainder (0) in $hi
				
#floating-point multiplication
	lwc1	$f0, x		# load f.p. value from memory at x
	lwc1	$f1, y		# load f.p. value from memory at y
	add.s	$f12, $f0, $f1	# add the values
	
	addi	$v0, $zero, 2	#opcode for print float
	syscall			#print the float value in $f12
	
	lwc1	$f0, big	#load a big value
	add.s	$f12, $f0, $f0	#should overflow
	addi	$v0, $zero, 2	#opcode for print float
	syscall			#print the float value in $f12
	
	lwc1	$f0, large	#load a large value
	mul.s	$f12, $f0, $f0	#should overflow
	addi	$v0, $zero, 2	#opcode for print float
	syscall			#print the float value in $f12

	lwc1	$f0, x		#load a finite value
	lwc1	$f1, zero	#load a zero
	div.s	$f12, $f0, $f1	#x/0 - overflows
	addi	$v0, $zero, 2	#opcode for print float
	syscall			#print the float value in $f12

	lwc1	$f1, zero	#load a zero
	div.s	$f12, $f1, $f1	#0/0 - undefined
	addi	$v0, $zero, 2	#opcode for print float
	syscall			#print the float value in $f12

	addi	$v0, $zero, 17  # syscall opcode for "exit"
	addi	$a0, $zero, 0	# exit status code (similar to java exit(0)
	syscall			# exit with status code 0

.data
.float
x: 1.0, -1.0, 0,
y: 3.625, 
z: -3.625, 12
4.625
biggest: 3.4028234E38	# approximate largest floating point value (single precesion)
smallest: 1.1754943E-38	# approximate smallest floating point value
big: 2.9E38
large: 1E20
zero: 0

.double
xx: 1.0, -1.0, 0,
yy: 3.625
zz: -3.625, 12