xref: /openbmc/linux/arch/sparc/lib/memmove.S (revision 1c2dd16a)
1/* memmove.S: Simple memmove implementation.
2 *
3 * Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com)
4 * Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
5 */
6
7#include <linux/linkage.h>
8#include <asm/export.h>
9
10	.text
11ENTRY(memmove) /* o0=dst o1=src o2=len */
12	brz,pn		%o2, 99f
13	 mov		%o0, %g1
14
15	cmp		%o0, %o1
16	bleu,pt		%xcc, 2f
17	 add		%o1, %o2, %g7
18	cmp		%g7, %o0
19	bleu,pt		%xcc, memcpy
20	 add		%o0, %o2, %o5
21	sub		%g7, 1, %o1
22
23	sub		%o5, 1, %o0
241:	ldub		[%o1], %g7
25	subcc		%o2, 1, %o2
26	sub		%o1, 1, %o1
27	stb		%g7, [%o0]
28	bne,pt		%icc, 1b
29	 sub		%o0, 1, %o0
3099:
31	retl
32	 mov		%g1, %o0
33
34	/* We can't just call memcpy for these memmove cases.  On some
35	 * chips the memcpy uses cache initializing stores and when dst
36	 * and src are close enough, those can clobber the source data
37	 * before we've loaded it in.
38	 */
392:	or		%o0, %o1, %g7
40	or		%o2, %g7, %g7
41	andcc		%g7, 0x7, %g0
42	bne,pn		%xcc, 4f
43	 nop
44
453:	ldx		[%o1], %g7
46	add		%o1, 8, %o1
47	subcc		%o2, 8, %o2
48	add		%o0, 8, %o0
49	bne,pt		%icc, 3b
50	 stx		%g7, [%o0 - 0x8]
51	ba,a,pt		%xcc, 99b
52
534:	ldub		[%o1], %g7
54	add		%o1, 1, %o1
55	subcc		%o2, 1, %o2
56	add		%o0, 1, %o0
57	bne,pt		%icc, 4b
58	 stb		%g7, [%o0 - 0x1]
59	ba,a,pt		%xcc, 99b
60ENDPROC(memmove)
61EXPORT_SYMBOL(memmove)
62