58 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			58 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|   | /* | ||
|  |  * Copyright (C) 2013 ARM Ltd. | ||
|  |  * | ||
|  |  * This program is free software; you can redistribute it and/or modify
 | ||
|  |  * it under the terms of the GNU General Public License version 2 as | ||
|  |  * published by the Free Software Foundation. | ||
|  |  * | ||
|  |  * This program is distributed in the hope that it will be useful, | ||
|  |  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 | ||
|  |  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | ||
|  |  * GNU General Public License for more details. | ||
|  |  * | ||
|  |  * You should have received a copy of the GNU General Public License | ||
|  |  * along with this program.  If not, see <http://www.gnu.org/licenses/>. | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <linux/linkage.h> | ||
|  | #include <asm/assembler.h> | ||
|  | 
 | ||
|  | /* | ||
|  |  * Move a buffer from src to test (alignment handled by the hardware). | ||
|  |  * If dest <= src, call memcpy, otherwise copy in reverse order. | ||
|  |  * | ||
|  |  * Parameters: | ||
|  |  *	x0 - dest | ||
|  |  *	x1 - src | ||
|  |  *	x2 - n | ||
|  |  * Returns: | ||
|  |  *	x0 - dest | ||
|  |  */ | ||
|  | ENTRY(memmove) | ||
|  | 	cmp	x0, x1 | ||
|  | 	b.ls	memcpy | ||
|  | 	add	x4, x0, x2 | ||
|  | 	add	x1, x1, x2 | ||
|  | 	subs	x2, x2, #8 | ||
|  | 	b.mi	2f | ||
|  | 1:	ldr	x3, [x1, #-8]! | ||
|  | 	subs	x2, x2, #8 | ||
|  | 	str	x3, [x4, #-8]! | ||
|  | 	b.pl	1b | ||
|  | 2:	adds	x2, x2, #4 | ||
|  | 	b.mi	3f | ||
|  | 	ldr	w3, [x1, #-4]! | ||
|  | 	sub	x2, x2, #4 | ||
|  | 	str	w3, [x4, #-4]! | ||
|  | 3:	adds	x2, x2, #2 | ||
|  | 	b.mi	4f | ||
|  | 	ldrh	w3, [x1, #-2]! | ||
|  | 	sub	x2, x2, #2 | ||
|  | 	strh	w3, [x4, #-2]! | ||
|  | 4:	adds	x2, x2, #1 | ||
|  | 	b.mi	5f | ||
|  | 	ldrb	w3, [x1, #-1] | ||
|  | 	strb	w3, [x4, #-1] | ||
|  | 5:	ret | ||
|  | ENDPROC(memmove) |