about summary refs log tree commit diff
path: root/sysdeps/x86_64/multiarch/strchr-avx2.S
blob: 71b1a1d06ef0603b84d1c41f69311977e8b25475 (plain) (blame)
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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
/* strchr/strchrnul optimized with AVX2.
   Copyright (C) 2017-2019 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 STRCHR
#  define STRCHR	__strchr_avx2
# endif

# ifdef USE_AS_WCSCHR
#  define VPBROADCAST	vpbroadcastd
#  define VPCMPEQ	vpcmpeqd
#  define CHAR_REG	esi
# else
#  define VPBROADCAST	vpbroadcastb
#  define VPCMPEQ	vpcmpeqb
#  define CHAR_REG	sil
# endif

# ifndef VZEROUPPER
#  define VZEROUPPER	vzeroupper
# endif

# define VEC_SIZE 32

	.section .text.avx,"ax",@progbits
ENTRY (STRCHR)
	movl	%edi, %ecx
	/* Broadcast CHAR to YMM0.  */
	vmovd	%esi, %xmm0
	vpxor	%xmm9, %xmm9, %xmm9
	VPBROADCAST %xmm0, %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)

	/* Check the first VEC_SIZE bytes.  Search for both CHAR and the
	   null byte.  */
	vmovdqu	(%rdi), %ymm8
	VPCMPEQ %ymm8, %ymm0, %ymm1
	VPCMPEQ %ymm8, %ymm9, %ymm2
	vpor	%ymm1, %ymm2, %ymm1
	vpmovmskb %ymm1, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x0)

	/* Align data for aligned loads in the loop.  */
	addq	$VEC_SIZE, %rdi
	andl	$(VEC_SIZE - 1), %ecx
	andq	$-VEC_SIZE, %rdi

	jmp	L(more_4x_vec)

	.p2align 4
L(cros_page_boundary):
	andl	$(VEC_SIZE - 1), %ecx
	andq	$-VEC_SIZE, %rdi
	vmovdqu	(%rdi), %ymm8
	VPCMPEQ %ymm8, %ymm0, %ymm1
	VPCMPEQ %ymm8, %ymm9, %ymm2
	vpor	%ymm1, %ymm2, %ymm1
	vpmovmskb %ymm1, %eax
	/* Remove the leading bytes.  */
	sarl	%cl, %eax
	testl	%eax, %eax
	jz	L(aligned_more)
	/* Found CHAR or the null byte.  */
	tzcntl	%eax, %eax
	addq	%rcx, %rax
# ifdef USE_AS_STRCHRNUL
	addq	%rdi, %rax
# else
	xorl	%edx, %edx
	leaq	(%rdi, %rax), %rax
	cmp	(%rax), %CHAR_REG
	cmovne	%rdx, %rax
# endif
	VZEROUPPER
	ret

	.p2align 4
L(aligned_more):
	addq	$VEC_SIZE, %rdi

L(more_4x_vec):
	/* Check the first 4 * VEC_SIZE.  Only one VEC_SIZE at a time
	   since data is only aligned to VEC_SIZE.  */
	vmovdqa	(%rdi), %ymm8
	VPCMPEQ %ymm8, %ymm0, %ymm1
	VPCMPEQ %ymm8, %ymm9, %ymm2
	vpor	%ymm1, %ymm2, %ymm1
	vpmovmskb %ymm1, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x0)

	vmovdqa	VEC_SIZE(%rdi), %ymm8
	VPCMPEQ %ymm8, %ymm0, %ymm1
	VPCMPEQ %ymm8, %ymm9, %ymm2
	vpor	%ymm1, %ymm2, %ymm1
	vpmovmskb %ymm1, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x1)

	vmovdqa	(VEC_SIZE * 2)(%rdi), %ymm8
	VPCMPEQ %ymm8, %ymm0, %ymm1
	VPCMPEQ %ymm8, %ymm9, %ymm2
	vpor	%ymm1, %ymm2, %ymm1
	vpmovmskb %ymm1, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x2)

	vmovdqa	(VEC_SIZE * 3)(%rdi), %ymm8
	VPCMPEQ %ymm8, %ymm0, %ymm1
	VPCMPEQ %ymm8, %ymm9, %ymm2
	vpor	%ymm1, %ymm2, %ymm1
	vpmovmskb %ymm1, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x3)

	addq	$(VEC_SIZE * 4), %rdi

	/* Align data to 4 * VEC_SIZE.  */
	movq	%rdi, %rcx
	andl	$(4 * VEC_SIZE - 1), %ecx
	andq	$-(4 * VEC_SIZE), %rdi

	.p2align 4
L(loop_4x_vec):
	/* Compare 4 * VEC at a time forward.  */
	vmovdqa	(%rdi), %ymm5
	vmovdqa	VEC_SIZE(%rdi), %ymm6
	vmovdqa	(VEC_SIZE * 2)(%rdi), %ymm7
	vmovdqa	(VEC_SIZE * 3)(%rdi), %ymm8

	VPCMPEQ %ymm5, %ymm0, %ymm1
	VPCMPEQ %ymm6, %ymm0, %ymm2
	VPCMPEQ %ymm7, %ymm0, %ymm3
	VPCMPEQ %ymm8, %ymm0, %ymm4

	VPCMPEQ %ymm5, %ymm9, %ymm5
	VPCMPEQ %ymm6, %ymm9, %ymm6
	VPCMPEQ %ymm7, %ymm9, %ymm7
	VPCMPEQ %ymm8, %ymm9, %ymm8

	vpor	%ymm1, %ymm5, %ymm1
	vpor	%ymm2, %ymm6, %ymm2
	vpor	%ymm3, %ymm7, %ymm3
	vpor	%ymm4, %ymm8, %ymm4

	vpor	%ymm1, %ymm2, %ymm5
	vpor	%ymm3, %ymm4, %ymm6

	vpor	%ymm5, %ymm6, %ymm5

	vpmovmskb %ymm5, %eax
	testl	%eax, %eax
	jnz	L(4x_vec_end)

	addq	$(VEC_SIZE * 4), %rdi

	jmp	L(loop_4x_vec)

	.p2align 4
L(first_vec_x0):
	/* Found CHAR or the null byte.  */
	tzcntl	%eax, %eax
# ifdef USE_AS_STRCHRNUL
	addq	%rdi, %rax
# else
	xorl	%edx, %edx
	leaq	(%rdi, %rax), %rax
	cmp	(%rax), %CHAR_REG
	cmovne	%rdx, %rax
# endif
	VZEROUPPER
	ret

	.p2align 4
L(first_vec_x1):
	tzcntl	%eax, %eax
# ifdef USE_AS_STRCHRNUL
	addq	$VEC_SIZE, %rax
	addq	%rdi, %rax
# else
	xorl	%edx, %edx
	leaq	VEC_SIZE(%rdi, %rax), %rax
	cmp	(%rax), %CHAR_REG
	cmovne	%rdx, %rax
# endif
	VZEROUPPER
	ret

	.p2align 4
L(first_vec_x2):
	tzcntl	%eax, %eax
# ifdef USE_AS_STRCHRNUL
	addq	$(VEC_SIZE * 2), %rax
	addq	%rdi, %rax
# else
	xorl	%edx, %edx
	leaq	(VEC_SIZE * 2)(%rdi, %rax), %rax
	cmp	(%rax), %CHAR_REG
	cmovne	%rdx, %rax
# endif
	VZEROUPPER
	ret

	.p2align 4
L(4x_vec_end):
	vpmovmskb %ymm1, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x0)
	vpmovmskb %ymm2, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x1)
	vpmovmskb %ymm3, %eax
	testl	%eax, %eax
	jnz	L(first_vec_x2)
	vpmovmskb %ymm4, %eax
	testl	%eax, %eax
L(first_vec_x3):
	tzcntl	%eax, %eax
# ifdef USE_AS_STRCHRNUL
	addq	$(VEC_SIZE * 3), %rax
	addq	%rdi, %rax
# else
	xorl	%edx, %edx
	leaq	(VEC_SIZE * 3)(%rdi, %rax), %rax
	cmp	(%rax), %CHAR_REG
	cmovne	%rdx, %rax
# endif
	VZEROUPPER
	ret

END (STRCHR)
#endif