summaryrefslogtreecommitdiffstats
path: root/src/arch/arm64/memmove.S
blob: 23b2a918f0f3d0d99db557156a33123489e8c507 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
/* SPDX-License-Identifier: GPL-2.0-only */
/* This file is part of the coreboot project. */

#include <arch/asm.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)