Skalarprodukt MIPS

dotprod.s

main:
	addi	$sp, $sp, -4				# stack für result
	sw		$zero, 0($sp)				# result = 0
	addi	$v0, $zero, 9				# syscall sbrk
	addi	$a0, $zero, 80				# allocate 20 words
	syscall								# malloc
	or		$a1, $v0, $zero				# &A[0]
	addi	$a2, $a1, 40				# &B[0]
	add		$a3, $zero, $sp				# result
	addi	$a0, $zero, 10				# n = 10
	add		$t0, $zero, $a1				# i
	addi	$t1, $t0, 80				# 
	addi	$t2, $zero, 0x7f			# 1.0
main_for:
	beq		$t0, $t1, main_for_end
	sw		$t2, 0($t0)
	addi	$t0, $t0, 4
main_for_end:
	jal		dotprod						# jump to dotprod and save position to $ra
	lwc1	$f12, 0($sp)				# result to print
	ori		$v0, $zero, 2				# print_float
	syscall
	ori		$v0, $zero, 10				# exit
	syscall
dotprod:    # $a0 = n, $a1 = &A[0], $a2 = &B[0], $a3 = &result, $t0 = i
			# Stack: $ra, sum => 8
			# $f0 = sum, $f1 = A[i], $f2 = B[i]
	addi    $sp, $sp, -8
	sw      $ra, 4($sp)					# Speichern der Rücksprungadresse
	sw      $zero, 0($sp)				# Speichern von sum = 0.0
	slti    $t0, $a0, 0					# $t0 = (n < 0)
	beq     $t0, $zero, dotprod_start	# if n >= 0 then dotprod_start
	addi    $v0, $zero, -1				# return -1
	jr		$ra							# jump to $ra
dotprod_start:
	or      $t0, $zero, $zero			# i = 0
dotprod_loop:
	beq		$t0, $a0, dotprod_end		# if i == n goto end
	lwc1	$f0, 0($sp)					# load sum to $f0
	sll		$t1, $t0, 2					# i * 4
	add		$t2, $a1, $t1				# $t2 = &A[i]
	add		$t3, $a2, $t1				# $t3 = &B[i]
	lwc1	$f1, 0($t2)					# load A[i] to $f1
	lwc1	$f2, 0($t3)					# load B[i] to $f2
	mul.s	$f1, $f1, $f2				# A[i] * B[i]
	add.s	$f0, $f0, $f1				# sum += (A[i] * B[i])
	swc1	$f0, 0($sp)					# store $f0 to sum
dotprod_end:
	lw		$t0, 0($sp)					# load sum to $t0
	sw		$t0, 0($a3)					# store sum to result
	addi	$sp, $sp, 8					# stack freigeben
	or		$v0, $zero, $zero			# return 0
	jr		$ra