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
|
/* Optimized strcmp implementation for PowerPC476.
Copyright (C) 2010-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
/* strcmp
Register Use
r0:temp return equality
r3:source1 address, return equality
r4:source2 address
Implementation description
Check 2 words from src1 and src2. If unequal jump to end and
return src1 > src2 or src1 < src2.
If null check bytes before null and then jump to end and
return src1 > src2, src1 < src2 or src1 = src2.
If src1 = src2 and no null, repeat. */
EALIGN (strcmp,5,0)
neg r7,r3
clrlwi r7,r7,20
neg r8,r4
clrlwi r8,r8,20
srwi. r7,r7,5
beq L(byte_loop)
srwi. r8,r8,5
beq L(byte_loop)
cmplw r7,r8
mtctr r7
ble L(big_loop)
mtctr r8
L(big_loop):
lwz r5,0(r3)
lwz r6,4(r3)
lwz r8,0(r4)
lwz r9,4(r4)
dlmzb. r12,r5,r6
bne L(end_check)
cmplw r5,r8
bne L(st1)
cmplw r6,r9
bne L(st1)
lwz r5,8(r3)
lwz r6,12(r3)
lwz r8,8(r4)
lwz r9,12(r4)
dlmzb. r12,r5,r6
bne L(end_check)
cmplw r5,r8
bne L(st1)
cmplw r6,r9
bne L(st1)
lwz r5,16(r3)
lwz r6,20(r3)
lwz r8,16(r4)
lwz r9,20(r4)
dlmzb. r12,r5,r6
bne L(end_check)
cmplw r5,r8
bne L(st1)
cmplw r6,r9
bne L(st1)
lwz r5,24(r3)
lwz r6,28(r3)
addi r3,r3,0x20
lwz r8,24(r4)
lwz r9,28(r4)
addi r4,r4,0x20
dlmzb. r12,r5,r6
bne L(end_check)
cmplw r5,r8
bne L(st1)
cmplw r6,r9
bne L(st1)
bdnz L(big_loop)
b L(byte_loop)
L(end_check):
subfic r12,r12,4
blt L(end_check2)
rlwinm r12,r12,3,0,31
srw r5,r5,r12
srw r8,r8,r12
cmplw r5,r8
bne L(st1)
b L(end_strcmp)
L(end_check2):
addi r12,r12,4
cmplw r5,r8
rlwinm r12,r12,3,0,31
bne L(st1)
srw r6,r6,r12
srw r9,r9,r12
cmplw r6,r9
bne L(st1)
L(end_strcmp):
addi r3,r0,0
blr
L(st1):
mfcr r3
blr
L(byte_loop):
lbz r5,0(r3)
addi r3,r3,1
lbz r6,0(r4)
addi r4,r4,1
cmplw r5,r6
bne L(st1)
cmpwi r5,0
beq L(end_strcmp)
b L(byte_loop)
END (strcmp)
libc_hidden_builtin_def (strcmp)
|
