mirror of https://gitee.com/openkylin/linux.git
62 lines
1.2 KiB
ArmAsm
62 lines
1.2 KiB
ArmAsm
/* memmove.S: Simple memmove implementation.
|
|
*
|
|
* Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com)
|
|
* Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/export.h>
|
|
|
|
.text
|
|
ENTRY(memmove) /* o0=dst o1=src o2=len */
|
|
brz,pn %o2, 99f
|
|
mov %o0, %g1
|
|
|
|
cmp %o0, %o1
|
|
bleu,pt %xcc, 2f
|
|
add %o1, %o2, %g7
|
|
cmp %g7, %o0
|
|
bleu,pt %xcc, memcpy
|
|
add %o0, %o2, %o5
|
|
sub %g7, 1, %o1
|
|
|
|
sub %o5, 1, %o0
|
|
1: ldub [%o1], %g7
|
|
subcc %o2, 1, %o2
|
|
sub %o1, 1, %o1
|
|
stb %g7, [%o0]
|
|
bne,pt %icc, 1b
|
|
sub %o0, 1, %o0
|
|
99:
|
|
retl
|
|
mov %g1, %o0
|
|
|
|
/* We can't just call memcpy for these memmove cases. On some
|
|
* chips the memcpy uses cache initializing stores and when dst
|
|
* and src are close enough, those can clobber the source data
|
|
* before we've loaded it in.
|
|
*/
|
|
2: or %o0, %o1, %g7
|
|
or %o2, %g7, %g7
|
|
andcc %g7, 0x7, %g0
|
|
bne,pn %xcc, 4f
|
|
nop
|
|
|
|
3: ldx [%o1], %g7
|
|
add %o1, 8, %o1
|
|
subcc %o2, 8, %o2
|
|
add %o0, 8, %o0
|
|
bne,pt %icc, 3b
|
|
stx %g7, [%o0 - 0x8]
|
|
ba,a,pt %xcc, 99b
|
|
|
|
4: ldub [%o1], %g7
|
|
add %o1, 1, %o1
|
|
subcc %o2, 1, %o2
|
|
add %o0, 1, %o0
|
|
bne,pt %icc, 4b
|
|
stb %g7, [%o0 - 0x1]
|
|
ba,a,pt %xcc, 99b
|
|
ENDPROC(memmove)
|
|
EXPORT_SYMBOL(memmove)
|