1/* Common definition for memcmp/wmemcmp ifunc selections.
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# include <init-arch.h>
21
22extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
23extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
24extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_movbe) attribute_hidden;
25extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_movbe_rtm) attribute_hidden;
26extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_movbe) attribute_hidden;
27
28static inline void *
29IFUNC_SELECTOR (void)
30{
31 const struct cpu_features* cpu_features = __get_cpu_features ();
32
33 if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
34 && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
35 && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
36 && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
37 {
38 if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
39 && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
40 return OPTIMIZE (evex_movbe);
41
42 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
43 return OPTIMIZE (avx2_movbe_rtm);
44
45 if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
46 return OPTIMIZE (avx2_movbe);
47 }
48
49 if (CPU_FEATURE_USABLE_P (cpu_features, SSSE3))
50 return OPTIMIZE (ssse3);
51
52 return OPTIMIZE (sse2);
53}
54

source code of glibc/sysdeps/x86_64/multiarch/ifunc-memcmp.h