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
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/*
* File: arch/blackfin/lib/memcpy.S
* Based on:
* Author:
*
* Created:
* Description: internal version of memcpy(), issued by the compiler
* to copy blocks of data around.
* This is really memmove() - it has to be able to deal with
* possible overlaps, because that ambiguity is when the compiler
* gives up and calls a function. We have our own, internal version
* so that we get something we trust, even if the user has redefined
* the normal symbol.
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/linkage.h>
/* void *memcpy(void *dest, const void *src, size_t n);
* R0 = To Address (dest) (leave unchanged to form result)
* R1 = From Address (src)
* R2 = count
*
* Note: Favours word alignment
*/
#ifdef CONFIG_MEMCPY_L1
.section .l1.text
#else
.text
#endif
.align 2
ENTRY(_memcpy)
CC = R2 <= 0; /* length not positive? */
IF CC JUMP .L_P1L2147483647; /* Nothing to do */
P0 = R0 ; /* dst*/
P1 = R1 ; /* src*/
P2 = R2 ; /* length */
/* check for overlapping data */
CC = R1 < R0; /* src < dst */
IF !CC JUMP .Lno_overlap;
R3 = R1 + R2;
CC = R0 < R3; /* and dst < src+len */
IF CC JUMP .Lhas_overlap;
.Lno_overlap:
/* Check for aligned data.*/
R3 = R1 | R0;
R1 = 0x3;
R3 = R3 & R1;
CC = R3; /* low bits set on either address? */
IF CC JUMP .Lnot_aligned;
/* Both addresses are word-aligned, so we can copy
at least part of the data using word copies.*/
P2 = P2 >> 2;
CC = P2 <= 2;
IF !CC JUMP .Lmore_than_seven;
/* less than eight bytes... */
P2 = R2;
LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
.Lthree_start:
R3 = B[P1++] (X);
.Lthree_end:
B[P0++] = R3;
RTS;
.Lmore_than_seven:
/* There's at least eight bytes to copy. */
P2 += -1; /* because we unroll one iteration */
LSETUP(.Lword_loops, .Lword_loope) LC0=P2;
I1 = P1;
R3 = [I1++];
#if ANOMALY_05000202
.Lword_loops:
[P0++] = R3;
.Lword_loope:
R3 = [I1++];
#else
.Lword_loops:
.Lword_loope:
MNOP || [P0++] = R3 || R3 = [I1++];
#endif
[P0++] = R3;
/* Any remaining bytes to copy? */
R3 = 0x3;
R3 = R2 & R3;
CC = R3 == 0;
P1 = I1; /* in case there's something left, */
IF !CC JUMP .Lbytes_left;
RTS;
.Lbytes_left: P2 = R3;
.Lnot_aligned:
/* From here, we're copying byte-by-byte. */
LSETUP (.Lbyte_start, .Lbyte_end) LC0=P2;
.Lbyte_start:
R1 = B[P1++] (X);
.Lbyte_end:
B[P0++] = R1;
.L_P1L2147483647:
RTS;
.Lhas_overlap:
/* Need to reverse the copying, because the
* dst would clobber the src.
* Don't bother to work out alignment for
* the reverse case.
*/
P0 = P0 + P2;
P0 += -1;
P1 = P1 + P2;
P1 += -1;
LSETUP(.Lover_start, .Lover_end) LC0=P2;
.Lover_start:
R1 = B[P1--] (X);
.Lover_end:
B[P0--] = R1;
RTS;
ENDPROC(_memcpy)
|
