1/* strrchr (str, ch) -- Return pointer to last occurrence of CH in STR.
2 Copyright (C) 2013-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19
20#include <sysdep.h>
21
22 .text
23ENTRY (strrchr)
24 movd %esi, %xmm1
25 movq %rdi, %rax
26 andl $4095, %eax
27 punpcklbw %xmm1, %xmm1
28 cmpq $4032, %rax
29 punpcklwd %xmm1, %xmm1
30 pshufd $0, %xmm1, %xmm1
31 ja L(cross_page)
32 movdqu (%rdi), %xmm0
33 pxor %xmm2, %xmm2
34 movdqa %xmm0, %xmm3
35 pcmpeqb %xmm1, %xmm0
36 pcmpeqb %xmm2, %xmm3
37 pmovmskb %xmm0, %ecx
38 pmovmskb %xmm3, %edx
39 testq %rdx, %rdx
40 je L(next_48_bytes)
41 leaq -1(%rdx), %rax
42 xorq %rdx, %rax
43 andq %rcx, %rax
44 je L(exit)
45 bsrq %rax, %rax
46 addq %rdi, %rax
47 ret
48
49 .p2align 4
50L(next_48_bytes):
51 movdqu 16(%rdi), %xmm4
52 movdqa %xmm4, %xmm5
53 movdqu 32(%rdi), %xmm3
54 pcmpeqb %xmm1, %xmm4
55 pcmpeqb %xmm2, %xmm5
56 movdqu 48(%rdi), %xmm0
57 pmovmskb %xmm5, %edx
58 movdqa %xmm3, %xmm5
59 pcmpeqb %xmm1, %xmm3
60 pcmpeqb %xmm2, %xmm5
61 pcmpeqb %xmm0, %xmm2
62 salq $16, %rdx
63 pmovmskb %xmm3, %r8d
64 pmovmskb %xmm5, %eax
65 pmovmskb %xmm2, %esi
66 salq $32, %r8
67 salq $32, %rax
68 pcmpeqb %xmm1, %xmm0
69 orq %rdx, %rax
70 movq %rsi, %rdx
71 pmovmskb %xmm4, %esi
72 salq $48, %rdx
73 salq $16, %rsi
74 orq %r8, %rsi
75 orq %rcx, %rsi
76 pmovmskb %xmm0, %ecx
77 salq $48, %rcx
78 orq %rcx, %rsi
79 orq %rdx, %rax
80 je L(loop_header2)
81 leaq -1(%rax), %rcx
82 xorq %rax, %rcx
83 andq %rcx, %rsi
84 je L(exit)
85 bsrq %rsi, %rsi
86 leaq (%rdi,%rsi), %rax
87 ret
88
89 .p2align 4
90L(loop_header2):
91 testq %rsi, %rsi
92 movq %rdi, %rcx
93 je L(no_c_found)
94L(loop_header):
95 addq $64, %rdi
96 pxor %xmm7, %xmm7
97 andq $-64, %rdi
98 jmp L(loop_entry)
99
100 .p2align 4
101L(loop64):
102 testq %rdx, %rdx
103 cmovne %rdx, %rsi
104 cmovne %rdi, %rcx
105 addq $64, %rdi
106L(loop_entry):
107 movdqa 32(%rdi), %xmm3
108 pxor %xmm6, %xmm6
109 movdqa 48(%rdi), %xmm2
110 movdqa %xmm3, %xmm0
111 movdqa 16(%rdi), %xmm4
112 pminub %xmm2, %xmm0
113 movdqa (%rdi), %xmm5
114 pminub %xmm4, %xmm0
115 pminub %xmm5, %xmm0
116 pcmpeqb %xmm7, %xmm0
117 pmovmskb %xmm0, %eax
118 movdqa %xmm5, %xmm0
119 pcmpeqb %xmm1, %xmm0
120 pmovmskb %xmm0, %r9d
121 movdqa %xmm4, %xmm0
122 pcmpeqb %xmm1, %xmm0
123 pmovmskb %xmm0, %edx
124 movdqa %xmm3, %xmm0
125 pcmpeqb %xmm1, %xmm0
126 salq $16, %rdx
127 pmovmskb %xmm0, %r10d
128 movdqa %xmm2, %xmm0
129 pcmpeqb %xmm1, %xmm0
130 salq $32, %r10
131 orq %r10, %rdx
132 pmovmskb %xmm0, %r8d
133 orq %r9, %rdx
134 salq $48, %r8
135 orq %r8, %rdx
136 testl %eax, %eax
137 je L(loop64)
138 pcmpeqb %xmm6, %xmm4
139 pcmpeqb %xmm6, %xmm3
140 pcmpeqb %xmm6, %xmm5
141 pmovmskb %xmm4, %eax
142 pmovmskb %xmm3, %r10d
143 pcmpeqb %xmm6, %xmm2
144 pmovmskb %xmm5, %r9d
145 salq $32, %r10
146 salq $16, %rax
147 pmovmskb %xmm2, %r8d
148 orq %r10, %rax
149 orq %r9, %rax
150 salq $48, %r8
151 orq %r8, %rax
152 leaq -1(%rax), %r8
153 xorq %rax, %r8
154 andq %r8, %rdx
155 cmovne %rdi, %rcx
156 cmovne %rdx, %rsi
157 bsrq %rsi, %rsi
158 leaq (%rcx,%rsi), %rax
159 ret
160
161 .p2align 4
162L(no_c_found):
163 movl $1, %esi
164 xorl %ecx, %ecx
165 jmp L(loop_header)
166
167 .p2align 4
168L(exit):
169 xorl %eax, %eax
170 ret
171
172 .p2align 4
173L(cross_page):
174 movq %rdi, %rax
175 pxor %xmm0, %xmm0
176 andq $-64, %rax
177 movdqu (%rax), %xmm5
178 movdqa %xmm5, %xmm6
179 movdqu 16(%rax), %xmm4
180 pcmpeqb %xmm1, %xmm5
181 pcmpeqb %xmm0, %xmm6
182 movdqu 32(%rax), %xmm3
183 pmovmskb %xmm6, %esi
184 movdqa %xmm4, %xmm6
185 movdqu 48(%rax), %xmm2
186 pcmpeqb %xmm1, %xmm4
187 pcmpeqb %xmm0, %xmm6
188 pmovmskb %xmm6, %edx
189 movdqa %xmm3, %xmm6
190 pcmpeqb %xmm1, %xmm3
191 pcmpeqb %xmm0, %xmm6
192 pcmpeqb %xmm2, %xmm0
193 salq $16, %rdx
194 pmovmskb %xmm3, %r9d
195 pmovmskb %xmm6, %r8d
196 pmovmskb %xmm0, %ecx
197 salq $32, %r9
198 salq $32, %r8
199 pcmpeqb %xmm1, %xmm2
200 orq %r8, %rdx
201 salq $48, %rcx
202 pmovmskb %xmm5, %r8d
203 orq %rsi, %rdx
204 pmovmskb %xmm4, %esi
205 orq %rcx, %rdx
206 pmovmskb %xmm2, %ecx
207 salq $16, %rsi
208 salq $48, %rcx
209 orq %r9, %rsi
210 orq %r8, %rsi
211 orq %rcx, %rsi
212 movl %edi, %ecx
213 subl %eax, %ecx
214 shrq %cl, %rdx
215 shrq %cl, %rsi
216 testq %rdx, %rdx
217 je L(loop_header2)
218 leaq -1(%rdx), %rax
219 xorq %rdx, %rax
220 andq %rax, %rsi
221 je L(exit)
222 bsrq %rsi, %rax
223 addq %rdi, %rax
224 ret
225END (strrchr)
226
227weak_alias (strrchr, rindex)
228libc_hidden_builtin_def (strrchr)
229