1/* Multiple versions of strchr.
2 All versions must be listed in ifunc-impl-list.c.
3 Copyright (C) 2009-2022 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20/* Define multiple versions only for the definition in libc. */
21#if IS_IN (libc)
22# define strchr __redirect_strchr
23# include <string.h>
24# undef strchr
25
26# define SYMBOL_NAME strchr
27# include <init-arch.h>
28
29extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
30extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_no_bsf) attribute_hidden;
31extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
32extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
33extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
34
35static inline void *
36IFUNC_SELECTOR (void)
37{
38 const struct cpu_features* cpu_features = __get_cpu_features ();
39
40 if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
41 && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
42 && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
43 {
44 if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
45 && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
46 return OPTIMIZE (evex);
47
48 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
49 return OPTIMIZE (avx2_rtm);
50
51 if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
52 return OPTIMIZE (avx2);
53 }
54
55 if (CPU_FEATURES_ARCH_P (cpu_features, Slow_BSF))
56 return OPTIMIZE (sse2_no_bsf);
57
58 return OPTIMIZE (sse2);
59}
60
61libc_ifunc_redirected (__redirect_strchr, strchr, IFUNC_SELECTOR ());
62weak_alias (strchr, index)
63# ifdef SHARED
64__hidden_ver1 (strchr, __GI_strchr, __redirect_strchr)
65 __attribute__((visibility ("hidden"))) __attribute_copy__ (strchr);
66# endif
67#endif
68

source code of glibc/sysdeps/x86_64/multiarch/strchr.c