1/* Common definition for ifunc selection optimized with EVEX.
2 All versions must be listed in ifunc-impl-list.c.
3 Copyright (C) 2017-2024 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 (evex) attribute_hidden;
23extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_rtm) attribute_hidden;
24
25extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
26extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
27
28extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
29
30static inline void *
31IFUNC_SELECTOR (void)
32{
33 const struct cpu_features *cpu_features = __get_cpu_features ();
34
35 /* NB: The X86_ISA_* feature check macros are evaluated at
36 compile time. */
37 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2)
38 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2)
39 && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
40 AVX_Fast_Unaligned_Load, ))
41 {
42 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
43 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
44 {
45 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
46 return OPTIMIZE (evex_rtm);
47
48 return OPTIMIZE (evex);
49 }
50
51 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
52 return OPTIMIZE (avx2_rtm);
53
54 if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
55 Prefer_No_VZEROUPPER, !))
56 return OPTIMIZE (avx2);
57 }
58
59 /* This is unreachable (compile time checked) if ISA level >= 3
60 so no need for a robust fallback here. */
61 return OPTIMIZE (sse2);
62}
63

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