about summary refs log tree commit diff
path: root/sysdeps/x86_64/strrchr.S
blob: 48c57e748893d12b8eb5dc52b8c30f0ea84f8db5 (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
/* strrchr (str, ch) -- Return pointer to last occurrence of CH in STR.
   Copyright (C) 2013-2019 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
   <https://www.gnu.org/licenses/>.  */


#include <sysdep.h>

	.text
ENTRY (strrchr)
	movd	%esi, %xmm1
	movq	%rdi, %rax
	andl	$4095, %eax
	punpcklbw	%xmm1, %xmm1
	cmpq	$4032, %rax
	punpcklwd	%xmm1, %xmm1
	pshufd	$0, %xmm1, %xmm1
	ja	L(cross_page)
	movdqu	(%rdi), %xmm0
	pxor	%xmm2, %xmm2
	movdqa	%xmm0, %xmm3
	pcmpeqb	%xmm1, %xmm0
	pcmpeqb	%xmm2, %xmm3
	pmovmskb	%xmm0, %ecx
	pmovmskb	%xmm3, %edx
	testq	%rdx, %rdx
	je	L(next_48_bytes)
	leaq	-1(%rdx), %rax
	xorq	%rdx, %rax
	andq	%rcx, %rax
	je	L(exit)
	bsrq	%rax, %rax
	addq	%rdi, %rax
	ret

	.p2align 4
L(next_48_bytes):
	movdqu	16(%rdi), %xmm4
	movdqa	%xmm4, %xmm5
	movdqu	32(%rdi), %xmm3
	pcmpeqb	%xmm1, %xmm4
	pcmpeqb	%xmm2, %xmm5
	movdqu	48(%rdi), %xmm0
	pmovmskb	%xmm5, %edx
	movdqa	%xmm3, %xmm5
	pcmpeqb	%xmm1, %xmm3
	pcmpeqb	%xmm2, %xmm5
	pcmpeqb	%xmm0, %xmm2
	salq	$16, %rdx
	pmovmskb	%xmm3, %r8d
	pmovmskb	%xmm5, %eax
	pmovmskb	%xmm2, %esi
	salq	$32, %r8
	salq	$32, %rax
	pcmpeqb	%xmm1, %xmm0
	orq	%rdx, %rax
	movq	%rsi, %rdx
	pmovmskb	%xmm4, %esi
	salq	$48, %rdx
	salq	$16, %rsi
	orq	%r8, %rsi
	orq	%rcx, %rsi
	pmovmskb	%xmm0, %ecx
	salq	$48, %rcx
	orq	%rcx, %rsi
	orq	%rdx, %rax
	je	L(loop_header2)
	leaq	-1(%rax), %rcx
	xorq	%rax, %rcx
	andq	%rcx, %rsi
	je	L(exit)
	bsrq	%rsi, %rsi
	leaq	(%rdi,%rsi), %rax
	ret

	.p2align 4
L(loop_header2):
	testq	%rsi, %rsi
	movq	%rdi, %rcx
	je	L(no_c_found)
L(loop_header):
	addq	$64, %rdi
	pxor	%xmm7, %xmm7
	andq	$-64, %rdi
	jmp	L(loop_entry)

	.p2align 4
L(loop64):
	testq	%rdx, %rdx
	cmovne	%rdx, %rsi
	cmovne	%rdi, %rcx
	addq	$64, %rdi
L(loop_entry):
	movdqa	32(%rdi), %xmm3
	pxor	%xmm6, %xmm6
	movdqa	48(%rdi), %xmm2
	movdqa	%xmm3, %xmm0
	movdqa	16(%rdi), %xmm4
	pminub	%xmm2, %xmm0
	movdqa	(%rdi), %xmm5
	pminub	%xmm4, %xmm0
	pminub	%xmm5, %xmm0
	pcmpeqb	%xmm7, %xmm0
	pmovmskb	%xmm0, %eax
	movdqa	%xmm5, %xmm0
	pcmpeqb	%xmm1, %xmm0
	pmovmskb	%xmm0, %r9d
	movdqa	%xmm4, %xmm0
	pcmpeqb	%xmm1, %xmm0
	pmovmskb	%xmm0, %edx
	movdqa	%xmm3, %xmm0
	pcmpeqb	%xmm1, %xmm0
	salq	$16, %rdx
	pmovmskb	%xmm0, %r10d
	movdqa	%xmm2, %xmm0
	pcmpeqb	%xmm1, %xmm0
	salq	$32, %r10
	orq	%r10, %rdx
	pmovmskb	%xmm0, %r8d
	orq	%r9, %rdx
	salq	$48, %r8
	orq	%r8, %rdx
	testl	%eax, %eax
	je	L(loop64)
	pcmpeqb	%xmm6, %xmm4
	pcmpeqb	%xmm6, %xmm3
	pcmpeqb	%xmm6, %xmm5
	pmovmskb	%xmm4, %eax
	pmovmskb	%xmm3, %r10d
	pcmpeqb	%xmm6, %xmm2
	pmovmskb	%xmm5, %r9d
	salq	$32, %r10
	salq	$16, %rax
	pmovmskb	%xmm2, %r8d
	orq	%r10, %rax
	orq	%r9, %rax
	salq	$48, %r8
	orq	%r8, %rax
	leaq	-1(%rax), %r8
	xorq	%rax, %r8
	andq	%r8, %rdx
	cmovne	%rdi, %rcx
	cmovne	%rdx, %rsi
	bsrq	%rsi, %rsi
	leaq	(%rcx,%rsi), %rax
	ret

	.p2align 4
L(no_c_found):
	movl	$1, %esi
	xorl	%ecx, %ecx
	jmp	L(loop_header)

	.p2align 4
L(exit):
	xorl	%eax, %eax
	ret

	.p2align 4
L(cross_page):
	movq	%rdi, %rax
	pxor	%xmm0, %xmm0
	andq	$-64, %rax
	movdqu	(%rax), %xmm5
	movdqa	%xmm5, %xmm6
	movdqu	16(%rax), %xmm4
	pcmpeqb	%xmm1, %xmm5
	pcmpeqb	%xmm0, %xmm6
	movdqu	32(%rax), %xmm3
	pmovmskb	%xmm6, %esi
	movdqa	%xmm4, %xmm6
	movdqu	48(%rax), %xmm2
	pcmpeqb	%xmm1, %xmm4
	pcmpeqb	%xmm0, %xmm6
	pmovmskb	%xmm6, %edx
	movdqa	%xmm3, %xmm6
	pcmpeqb	%xmm1, %xmm3
	pcmpeqb	%xmm0, %xmm6
	pcmpeqb	%xmm2, %xmm0
	salq	$16, %rdx
	pmovmskb	%xmm3, %r9d
	pmovmskb	%xmm6, %r8d
	pmovmskb	%xmm0, %ecx
	salq	$32, %r9
	salq	$32, %r8
	pcmpeqb	%xmm1, %xmm2
	orq	%r8, %rdx
	salq	$48, %rcx
	pmovmskb	%xmm5, %r8d
	orq	%rsi, %rdx
	pmovmskb	%xmm4, %esi
	orq	%rcx, %rdx
	pmovmskb	%xmm2, %ecx
	salq	$16, %rsi
	salq	$48, %rcx
	orq	%r9, %rsi
	orq	%r8, %rsi
	orq	%rcx, %rsi
	movl	%edi, %ecx
	subl	%eax, %ecx
	shrq	%cl, %rdx
	shrq	%cl, %rsi
	testq	%rdx, %rdx
	je	L(loop_header2)
	leaq	-1(%rdx), %rax
	xorq	%rdx, %rax
	andq	%rax, %rsi
	je	L(exit)
	bsrq	%rsi, %rax
	addq	%rdi, %rax
	ret
END (strrchr)

weak_alias (strrchr, rindex)
libc_hidden_builtin_def (strrchr)