blob: 012cdb6ca4677b09da150b3f8b61ae98879b5952 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* 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
David S. Miller8695c372012-05-11 20:33:22 -07007#include <linux/linkage.h>
Al Virod3867f042016-01-16 21:39:30 -05008#include <asm/export.h>
David S. Miller8695c372012-05-11 20:33:22 -07009
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 .text
David S. Miller8695c372012-05-11 20:33:22 -070011ENTRY(memmove) /* o0=dst o1=src o2=len */
David S. Miller2077cef2015-03-23 09:22:10 -070012 brz,pn %o2, 99f
13 mov %o0, %g1
14
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 cmp %o0, %o1
David S. Miller2077cef2015-03-23 09:22:10 -070016 bleu,pt %xcc, 2f
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 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
David S. Miller2077cef2015-03-23 09:22:10 -07003099:
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 retl
32 mov %g1, %o0
David S. Miller2077cef2015-03-23 09:22:10 -070033
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
David S. Miller8695c372012-05-11 20:33:22 -070060ENDPROC(memmove)
Al Virod3867f042016-01-16 21:39:30 -050061EXPORT_SYMBOL(memmove)