.global func
.section .text

func:
	MOV R0,#3  @Move 3 to R0
	MOV R1,#5  @Move 5 to R1
	MOV R2,#0  @Move 0 to R2
loop:
add5:
	ADD R2,R2,R1  @Add R1 to R2
	ADD R1,R1,#5  @Increment R1 by 5
add3:
	ADD R2,R2,R0  @Add R0 to R2
	ADD R0,R0,#3  @Increment R0 by 3

check3:
	CMP R0,#1000  @Is R0 less than 1000?
	BLT check5  @If true, check 5
	BGE rmv15  @If the multiple of 3 is greater than 1000, go to rmv15

check5:
	CMP R1,#1000  @Is R1 less than 1000?
	BLT loop  @If true, go back to loop
	BGE add3  @If the multiple of 5 reaches 1000, go to add3 - Continue adding multiples of 3, because those wouldn't have reached 1000 yet

rmv15:
	MOV R0,#15  @The loop that follows is intended to subtract multiples of 15, which would have been added twice - 3, 6, 9, 12, 15, 18 ; 5, 10, 15, 20
loop2:
	SUB R2,R2,R0
	ADD R0,R0,#15
	CMP R0,#1000
	BLT loop2


return:
	MOV R0,R2
	BX lr

.section .data