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
148
149
150
151
152
153
154
155
156
157
158
|
/* strchr with SSE2 with bsf
Copyright (C) 2011 Free Software Foundation, Inc.
Contributed by Intel Corporation.
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
<http://www.gnu.org/licenses/>. */
#ifndef NOT_IN_libc
# include <sysdep.h>
# define CFI_PUSH(REG) \
cfi_adjust_cfa_offset (4); \
cfi_rel_offset (REG, 0)
# define CFI_POP(REG) \
cfi_adjust_cfa_offset (-4); \
cfi_restore (REG)
# define PUSH(REG) pushl REG; CFI_PUSH (REG)
# define POP(REG) popl REG; CFI_POP (REG)
# define PARMS 8
# define ENTRANCE PUSH(%edi)
# define RETURN POP(%edi); ret; CFI_PUSH(%edi);
# define STR1 PARMS
# define STR2 STR1+4
.text
ENTRY (__strchr_sse2_bsf)
ENTRANCE
mov STR1(%esp), %ecx
movd STR2(%esp), %xmm1
pxor %xmm2, %xmm2
mov %ecx, %edi
punpcklbw %xmm1, %xmm1
punpcklbw %xmm1, %xmm1
/* ECX has OFFSET. */
and $15, %ecx
pshufd $0, %xmm1, %xmm1
je L(loop)
/* Handle unaligned string. */
and $-16, %edi
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
pcmpeqb %xmm1, %xmm0
/* Find where NULL is. */
pmovmskb %xmm2, %edx
/* Check if there is a match. */
pmovmskb %xmm0, %eax
/* Remove the leading bytes. */
sarl %cl, %edx
sarl %cl, %eax
test %eax, %eax
je L(unaligned_no_match)
/* Check which byte is a match. */
bsf %eax, %eax
/* Is there a NULL? */
test %edx, %edx
je L(unaligned_match)
bsf %edx, %edx
cmpl %edx, %eax
/* Return NULL if NULL comes first. */
ja L(return_null)
L(unaligned_match):
add %edi, %eax
add %ecx, %eax
RETURN
.p2align 4
L(unaligned_no_match):
test %edx, %edx
jne L(return_null)
pxor %xmm2, %xmm2
add $16, %edi
.p2align 4
/* Loop start on aligned string. */
L(loop):
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
add $16, %edi
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
or %eax, %edx
jnz L(matches)
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
add $16, %edi
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
or %eax, %edx
jnz L(matches)
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
add $16, %edi
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
or %eax, %edx
jnz L(matches)
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
add $16, %edi
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
or %eax, %edx
jnz L(matches)
jmp L(loop)
L(matches):
pmovmskb %xmm2, %edx
test %eax, %eax
jz L(return_null)
bsf %eax, %eax
/* There is a match. First find where NULL is. */
test %edx, %edx
je L(match)
bsf %edx, %ecx
/* Check if NULL comes first. */
cmpl %ecx, %eax
ja L(return_null)
L(match):
sub $16, %edi
add %edi, %eax
RETURN
/* Return NULL. */
.p2align 4
L(return_null):
xor %eax, %eax
RETURN
END (__strchr_sse2_bsf)
#endif
|
