; (1) 程序功能：________
num_of_words	EQU	18

	AREA	CopyData, CODE, READONLY
	ENTRY
	
start
	LDR	R0, = Src
	LDR	R1, = Dst
	MOV	R2, #num_of_words
	LDR	SP, =0x40001000
	MOVS	R3, R2, LSR #2 ; (2) 语句功能：________
	BEQ	Copy_Words
	STMFD	SP!, {R5-R8}

Copy_4Words
	LDMIA	R0!, {R5-R8} ; (3) 语句功能：________
	STMIA	R1!, {R5-R8} ; (4) 语句功能：________
	SUBS	R3, R3, #1
	BNE	Copy_4Words ; (5) 语句功能：________
	LDMFD	SP!, {R5-R8}
	
Copy_Words
	ANDS	R2, R2, #3 ; (6) 语句功能：________
	BEQ	Stop
Copy_Word
	LDR	R3, [R0], #4
	STR	R3, [R1], #4
	SUBS	R2, R2, #1
	BNE	Copy_Word

Stop
	B	Stop
	LTORG ; (7) 语句功能：________
	
Src
	DCD	1,2,3,4,5,6,7,8,9,0xA,0xB,0xC,0xD,0xE,0xF,0x10,0x11,0x12
	
Dst
	DCD	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
	
	END