1 /* Multiple versions of strncmp.
2 All versions must be listed in ifunc-impl-list.c.
3 Copyright (C) 2017-2021 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 strncmp __redirect_strncmp
23 # include <string.h>
24 # undef strncmp
25
26 # define SYMBOL_NAME strncmp
27 # include <init-arch.h>
28
29 extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
30 extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
31 extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;
32 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
33 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
34 extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
35
36 static inline void *
IFUNC_SELECTOR(void)37 IFUNC_SELECTOR (void)
38 {
39 const struct cpu_features* cpu_features = __get_cpu_features ();
40
41 if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
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 && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
47 return OPTIMIZE (evex);
48
49 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
50 return OPTIMIZE (avx2_rtm);
51
52 if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
53 return OPTIMIZE (avx2);
54 }
55
56 if (CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)
57 && !CPU_FEATURES_ARCH_P (cpu_features, Slow_SSE4_2))
58 return OPTIMIZE (sse42);
59
60 if (CPU_FEATURE_USABLE_P (cpu_features, SSSE3))
61 return OPTIMIZE (ssse3);
62
63 return OPTIMIZE (sse2);
64 }
65
66 libc_ifunc_redirected (__redirect_strncmp, strncmp, IFUNC_SELECTOR ());
67
68 # ifdef SHARED
69 __hidden_ver1 (strncmp, __GI_strncmp, __redirect_strncmp)
70 __attribute__ ((visibility ("hidden"))) __attribute_copy__ (strncmp);
71 # endif
72 #endif
73