MIPS example for review session for CS152 SP04 Prereq. quiz
By John Gibson

vector Junk:
------------
Arugments:

1: Source address 1
2: Source address 2
3: Destination address of summed cosine
4: Destination address of summed sine
5: Destination address of summed tangent
6: Length of vector remaining

Return Values:
1: The sum of all the numbers in both source vectors



Library functions:
------------------
sine
Arguments:
1: Number to be sined

Return Values:
1: The sine of the number


cosine
Arguments:
1: Number to be cosined

Return Values:
1: The cosine of the number


tan
Arguments:
1: Number to be tangented

Return Values:
1: The tangented of the number



Questions:
----------
Why would a frame pointer be useful?



------

vector_junk:

addiu $sp, $sp, -32	# save registers
sw $ra, 0($sp)
sw $a0, 4($sp)
sw $a1, 8($sp)
sw $a2, 12($sp)
sw $a3, 16($sp)
sw $s0, 20($sp)		# sum of pair of elts. in source vectors
sw $s1, 24($sp)
sw $s2, 28($sp)
lw $s1, 32($sp)		# addr 5 tan
lw $s2, 36($sp)		# length

lw $t0, 0($a0)
lw $t1, 0($a1)

addu $s0, $t0, $t1
addu $a0, $s0, $zero

jal cosine		# call to calculate cosine
srl $0, $0, 0

lw $a2, 12($sp)
sw $v0, 0($a2)
addu $a0, $s0, $zero

jal sine
srl $0, $0, 0

lw $a3, 16($sp)
sw $v0, 0($a3)
addu $a0, $s0, $zero

jal tan
srl $0, $0, 0

sw $v0, 0($s1)

addiu $s2, $s2, -1
beq $s2, $0, done	# check to see if we're done
srl $0, $0, 0

lw $a0, 0($sp)
lw $a1, 4($sp)
lw $a2, 8($sp)
lw $a3, 12($sp)
addiu $a0, $a0, 4
addiu $a1, $a1, 4
addiu $a2, $a2, 4
addiu $a3, $a3, 4
addiu $s1, $s1, 4
addiu $sp, $sp, -8
sw $s1, 0($sp)		# Store args 5 and 6 for the next call
sw $s2, 4($sp)

jal vector_junk
srl $0, $0, 0

addu $v0, $v0, $s0

lw $ra, 8($sp)
lw $s0, 28($sp) 
lw $s1, 32($sp)
lw $s2, 36($sp)
addiu $sp, $sp, 40

jr $ra
srl $0, $0, 0

done:

addu $v0, $zero, $s0

lw $ra, 0($sp)
lw $s0, 20($sp) 
lw $s1, 24($sp)
lw $s2, 28($sp)
addiu $sp, $sp, 32

jr $ra
srl $0, $0, 0