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
|
/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
Ported to mips3 n32/n64 by Alexandre Oliva <aoliva@redhat.com>
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include <endian.h>
#include <sys/asm.h>
/* void *memcpy(void *s1, const void *s2, size_t n);
This could probably be optimized further. */
#if __BYTE_ORDER == __BIG_ENDIAN
# define LDHI ldl /* high part is left in big-endian */
# define SDHI sdl /* high part is left in big-endian */
# define LDLO ldr /* low part is right in big-endian */
# define SDLO sdr /* low part is right in big-endian */
#else
# define LDHI ldr /* high part is right in little-endian */
# define SDHI sdr /* high part is right in little-endian */
# define LDLO ldl /* low part is left in little-endian */
# define SDLO sdl /* low part is left in little-endian */
#endif
ENTRY (memcpy)
.set noreorder
slti t0, a2, 16 # Less than 16?
bne t0, zero, L(last16)
move v0, a0 # Setup exit value before too late
xor t0, a1, a0 # Find a0/a1 displacement
andi t0, 0x7
bne t0, zero, L(shift) # Go handle the unaligned case
PTR_SUBU t1, zero, a1
andi t1, 0x7 # a0/a1 are aligned, but are we
beq t1, zero, L(chk8w) # starting in the middle of a word?
PTR_SUBU a2, t1
LDHI t0, 0(a1) # Yes we are... take care of that
PTR_ADDU a1, t1
SDHI t0, 0(a0)
PTR_ADDU a0, t1
L(chk8w):
andi t0, a2, 0x3f # 64 or more bytes left?
beq t0, a2, L(chk1w)
PTR_SUBU a3, a2, t0 # Yes
PTR_ADDU a3, a1 # a3 = end address of loop
move a2, t0 # a2 = what will be left after loop
L(lop8w):
ld t0, 0(a1) # Loop taking 8 words at a time
ld t1, 8(a1)
ld t2, 16(a1)
ld t3, 24(a1)
ld ta0, 32(a1)
ld ta1, 40(a1)
ld ta2, 48(a1)
ld ta3, 56(a1)
PTR_ADDIU a0, 64
PTR_ADDIU a1, 64
sd t0, -64(a0)
sd t1, -56(a0)
sd t2, -48(a0)
sd t3, -40(a0)
sd ta0, -32(a0)
sd ta1, -24(a0)
sd ta2, -16(a0)
bne a1, a3, L(lop8w)
sd ta3, -8(a0)
L(chk1w):
andi t0, a2, 0x7 # 8 or more bytes left?
beq t0, a2, L(last16)
PTR_SUBU a3, a2, t0 # Yes, handle them one dword at a time
PTR_ADDU a3, a1 # a3 again end address
move a2, t0
L(lop1w):
ld t0, 0(a1)
PTR_ADDIU a0, 8
PTR_ADDIU a1, 8
bne a1, a3, L(lop1w)
sd t0, -8(a0)
L(last16):
blez a2, L(lst16e) # Handle last 16 bytes, one at a time
PTR_ADDU a3, a2, a1
L(lst16l):
lb t0, 0(a1)
PTR_ADDIU a0, 1
PTR_ADDIU a1, 1
bne a1, a3, L(lst16l)
sb t0, -1(a0)
L(lst16e):
jr ra # Bye, bye
nop
L(shift):
PTR_SUBU a3, zero, a0 # Src and Dest unaligned
andi a3, 0x7 # (unoptimized case...)
beq a3, zero, L(shft1)
PTR_SUBU a2, a3 # a2 = bytes left
LDHI t0, 0(a1) # Take care of first odd part
LDLO t0, 7(a1)
PTR_ADDU a1, a3
SDHI t0, 0(a0)
PTR_ADDU a0, a3
L(shft1):
andi t0, a2, 0x7
PTR_SUBU a3, a2, t0
PTR_ADDU a3, a1
L(shfth):
LDHI t1, 0(a1) # Limp through, dword by dword
LDLO t1, 7(a1)
PTR_ADDIU a0, 8
PTR_ADDIU a1, 8
bne a1, a3, L(shfth)
sd t1, -8(a0)
b L(last16) # Handle anything which may be left
move a2, t0
.set reorder
END (memcpy)
libc_hidden_builtin_def (memcpy)
|
