1/* Multiple versions of strcmp.
2 All versions must be listed in ifunc-impl-list.c.
3 Copyright (C) 2017-2022 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 strcmp __redirect_strcmp
23# include <string.h>
24# undef strcmp
25
26# define SYMBOL_NAME strcmp
27# include <init-arch.h>
28
29extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
30
31extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
32extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
33
34extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;
35
36extern __typeof (REDIRECT_NAME)
37 OPTIMIZE (sse2_unaligned) attribute_hidden;
38extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
39
40
41
42static inline void *
43IFUNC_SELECTOR (void)
44{
45 const struct cpu_features *cpu_features = __get_cpu_features ();
46
47 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2)
48 && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
49 AVX_Fast_Unaligned_Load, ))
50 {
51 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
52 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
53 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2))
54 return OPTIMIZE (evex);
55
56 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
57 return OPTIMIZE (avx2_rtm);
58
59 if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
60 Prefer_No_VZEROUPPER, !))
61 return OPTIMIZE (avx2);
62 }
63
64 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)
65 /* Keep this as runtime check. Some ISA level >= 2 CPUs such as
66 Tremont, Silvermont, and more check this. */
67 && !CPU_FEATURES_ARCH_P (cpu_features, Slow_SSE4_2))
68 return OPTIMIZE (sse42);
69
70 /* Keep this as runtime check. The standard SSE2 version has
71 meaningful optimizations around keeping all loads aligned in the
72 main loop which can benefit some ISA level >= 2 CPUs. */
73 if (CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Load))
74 return OPTIMIZE (sse2_unaligned);
75
76 return OPTIMIZE (sse2);
77}
78
79libc_ifunc_redirected (__redirect_strcmp, strcmp, IFUNC_SELECTOR ());
80
81# ifdef SHARED
82__hidden_ver1 (strcmp, __GI_strcmp, __redirect_strcmp)
83 __attribute__ ((visibility ("hidden"))) __attribute_copy__ (strcmp);
84# endif
85#endif
86