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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
|
/* strrchr/wcsrchr optimized with AVX2.
Copyright (C) 2017-2018 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
<http://www.gnu.org/licenses/>. */
#if IS_IN (libc)
# include <sysdep.h>
# ifndef STRRCHR
# define STRRCHR __strrchr_avx2
# endif
# ifdef USE_AS_WCSRCHR
# define VPBROADCAST vpbroadcastd
# define VPCMPEQ vpcmpeqd
# else
# define VPBROADCAST vpbroadcastb
# define VPCMPEQ vpcmpeqb
# endif
# ifndef VZEROUPPER
# define VZEROUPPER vzeroupper
# endif
# define VEC_SIZE 32
.section .text.avx,"ax",@progbits
ENTRY (STRRCHR)
movd %esi, %xmm4
movl %edi, %ecx
/* Broadcast CHAR to YMM4. */
VPBROADCAST %xmm4, %ymm4
vpxor %ymm0, %ymm0, %ymm0
/* Check if we may cross page boundary with one vector load. */
andl $(2 * VEC_SIZE - 1), %ecx
cmpl $VEC_SIZE, %ecx
ja L(cros_page_boundary)
vmovdqu (%rdi), %ymm1
VPCMPEQ %ymm1, %ymm0, %ymm2
VPCMPEQ %ymm1, %ymm4, %ymm3
vpmovmskb %ymm2, %ecx
vpmovmskb %ymm3, %eax
addq $VEC_SIZE, %rdi
testl %eax, %eax
jnz L(first_vec)
testl %ecx, %ecx
jnz L(return_null)
andq $-VEC_SIZE, %rdi
xorl %edx, %edx
jmp L(aligned_loop)
.p2align 4
L(first_vec):
/* Check if there is a nul CHAR. */
testl %ecx, %ecx
jnz L(char_and_nul_in_first_vec)
/* Remember the match and keep searching. */
movl %eax, %edx
movq %rdi, %rsi
andq $-VEC_SIZE, %rdi
jmp L(aligned_loop)
.p2align 4
L(cros_page_boundary):
andl $(VEC_SIZE - 1), %ecx
andq $-VEC_SIZE, %rdi
vmovdqa (%rdi), %ymm1
VPCMPEQ %ymm1, %ymm0, %ymm2
VPCMPEQ %ymm1, %ymm4, %ymm3
vpmovmskb %ymm2, %edx
vpmovmskb %ymm3, %eax
shrl %cl, %edx
shrl %cl, %eax
addq $VEC_SIZE, %rdi
/* Check if there is a CHAR. */
testl %eax, %eax
jnz L(found_char)
testl %edx, %edx
jnz L(return_null)
jmp L(aligned_loop)
.p2align 4
L(found_char):
testl %edx, %edx
jnz L(char_and_nul)
/* Remember the match and keep searching. */
movl %eax, %edx
leaq (%rdi, %rcx), %rsi
.p2align 4
L(aligned_loop):
vmovdqa (%rdi), %ymm1
VPCMPEQ %ymm1, %ymm0, %ymm2
addq $VEC_SIZE, %rdi
VPCMPEQ %ymm1, %ymm4, %ymm3
vpmovmskb %ymm2, %ecx
vpmovmskb %ymm3, %eax
orl %eax, %ecx
jnz L(char_nor_null)
vmovdqa (%rdi), %ymm1
VPCMPEQ %ymm1, %ymm0, %ymm2
add $VEC_SIZE, %rdi
VPCMPEQ %ymm1, %ymm4, %ymm3
vpmovmskb %ymm2, %ecx
vpmovmskb %ymm3, %eax
orl %eax, %ecx
jnz L(char_nor_null)
vmovdqa (%rdi), %ymm1
VPCMPEQ %ymm1, %ymm0, %ymm2
addq $VEC_SIZE, %rdi
VPCMPEQ %ymm1, %ymm4, %ymm3
vpmovmskb %ymm2, %ecx
vpmovmskb %ymm3, %eax
orl %eax, %ecx
jnz L(char_nor_null)
vmovdqa (%rdi), %ymm1
VPCMPEQ %ymm1, %ymm0, %ymm2
addq $VEC_SIZE, %rdi
VPCMPEQ %ymm1, %ymm4, %ymm3
vpmovmskb %ymm2, %ecx
vpmovmskb %ymm3, %eax
orl %eax, %ecx
jz L(aligned_loop)
.p2align 4
L(char_nor_null):
/* Find a CHAR or a nul CHAR in a loop. */
testl %eax, %eax
jnz L(match)
L(return_value):
testl %edx, %edx
jz L(return_null)
movl %edx, %eax
movq %rsi, %rdi
# ifdef USE_AS_WCSRCHR
/* Keep the first bit for each matching CHAR for bsr. */
andl $0x11111111, %eax
# endif
bsrl %eax, %eax
leaq -VEC_SIZE(%rdi, %rax), %rax
VZEROUPPER
ret
.p2align 4
L(match):
/* Find a CHAR. Check if there is a nul CHAR. */
vpmovmskb %ymm2, %ecx
testl %ecx, %ecx
jnz L(find_nul)
/* Remember the match and keep searching. */
movl %eax, %edx
movq %rdi, %rsi
jmp L(aligned_loop)
.p2align 4
L(find_nul):
# ifdef USE_AS_WCSRCHR
/* Keep the first bit for each matching CHAR for bsr. */
andl $0x11111111, %ecx
andl $0x11111111, %eax
# endif
/* Mask out any matching bits after the nul CHAR. */
movl %ecx, %r8d
subl $1, %r8d
xorl %ecx, %r8d
andl %r8d, %eax
testl %eax, %eax
/* If there is no CHAR here, return the remembered one. */
jz L(return_value)
bsrl %eax, %eax
leaq -VEC_SIZE(%rdi, %rax), %rax
VZEROUPPER
ret
.p2align 4
L(char_and_nul):
/* Find both a CHAR and a nul CHAR. */
addq %rcx, %rdi
movl %edx, %ecx
L(char_and_nul_in_first_vec):
# ifdef USE_AS_WCSRCHR
/* Keep the first bit for each matching CHAR for bsr. */
andl $0x11111111, %ecx
andl $0x11111111, %eax
# endif
/* Mask out any matching bits after the nul CHAR. */
movl %ecx, %r8d
subl $1, %r8d
xorl %ecx, %r8d
andl %r8d, %eax
testl %eax, %eax
/* Return null pointer if the nul CHAR comes first. */
jz L(return_null)
bsrl %eax, %eax
leaq -VEC_SIZE(%rdi, %rax), %rax
VZEROUPPER
ret
.p2align 4
L(return_null):
xorl %eax, %eax
VZEROUPPER
ret
END (STRRCHR)
#endif
|
