1/* Common definition for memset/memset_chk ifunc selections.
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 (erms) attribute_hidden;
23
24extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned)
25 attribute_hidden;
26extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_unaligned_erms)
27 attribute_hidden;
28extern __typeof (REDIRECT_NAME) OPTIMIZE (avx512_no_vzeroupper)
29 attribute_hidden;
30
31extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned)
32 attribute_hidden;
33extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_unaligned_erms)
34 attribute_hidden;
35
36extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned) attribute_hidden;
37extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_erms)
38 attribute_hidden;
39extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_rtm)
40 attribute_hidden;
41extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_unaligned_erms_rtm)
42 attribute_hidden;
43
44extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned)
45 attribute_hidden;
46extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned_erms)
47 attribute_hidden;
48
49static inline void *
50IFUNC_SELECTOR (void)
51{
52 const struct cpu_features *cpu_features = __get_cpu_features ();
53
54 if (CPU_FEATURES_ARCH_P (cpu_features, Prefer_ERMS))
55 return OPTIMIZE (erms);
56
57 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
58 && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
59 {
60 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
61 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
62 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2))
63 {
64 if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
65 return OPTIMIZE (avx512_unaligned_erms);
66
67 return OPTIMIZE (avx512_unaligned);
68 }
69
70 return OPTIMIZE (avx512_no_vzeroupper);
71 }
72
73 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2))
74 {
75 if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
76 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
77 && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2))
78 {
79 if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
80 return OPTIMIZE (evex_unaligned_erms);
81
82 return OPTIMIZE (evex_unaligned);
83 }
84
85 if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
86 {
87 if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
88 return OPTIMIZE (avx2_unaligned_erms_rtm);
89
90 return OPTIMIZE (avx2_unaligned_rtm);
91 }
92
93 if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
94 Prefer_No_VZEROUPPER, !))
95 {
96 if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
97 return OPTIMIZE (avx2_unaligned_erms);
98
99 return OPTIMIZE (avx2_unaligned);
100 }
101 }
102
103 if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
104 return OPTIMIZE (sse2_unaligned_erms);
105
106 return OPTIMIZE (sse2_unaligned);
107}
108

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