sysdeps/x86_64/multiarch/bzero.c

   1 /* Multiple versions of bzero.
   2    All versions must be listed in ifunc-impl-list.c.
   3    Copyright (C) 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 __bzero __redirect___bzero
  23 # include <string.h>
  24 # undef __bzero
  25
  26 # define SYMBOL_NAME __bzero
  27 # include <init-arch.h>
  28
  29 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned)
  30   attribute_hidden;
  31 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned_erms)
  32   attribute_hidden;
  33 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned) attribute_hidden;
  34 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms)
  35   attribute_hidden;
  36 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_rtm)
  37   attribute_hidden;
  38 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms_rtm)
  39   attribute_hidden;
  40 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned)
  41   attribute_hidden;
  42 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned_erms)
  43   attribute_hidden;
  44 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned)
  45   attribute_hidden;
  46 extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned_erms)
  47   attribute_hidden;
  48
  49 static inline void *
  50 IFUNC_SELECTOR (void)
  51 {
  52   const struct cpu_features* cpu_features = __get_cpu_features ();
  53
  54   if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
  55       && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
  56     {
  57       if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
  58           && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
  59           && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
  60         {
  61           if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
  62             return OPTIMIZE1 (avx512_unaligned_erms);
  63
  64           return OPTIMIZE1 (avx512_unaligned);
  65         }
  66     }
  67
  68   if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))
  69     {
  70       if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
  71           && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
  72           && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
  73         {
  74           if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
  75             return OPTIMIZE1 (evex_unaligned_erms);
  76
  77           return OPTIMIZE1 (evex_unaligned);
  78         }
  79
  80       if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
  81         {
  82           if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
  83             return OPTIMIZE1 (avx2_unaligned_erms_rtm);
  84
  85           return OPTIMIZE1 (avx2_unaligned_rtm);
  86         }
  87
  88       if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
  89         {
  90           if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
  91             return OPTIMIZE1 (avx2_unaligned_erms);
  92
  93           return OPTIMIZE1 (avx2_unaligned);
  94         }
  95     }
  96
  97   if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
  98     return OPTIMIZE1 (sse2_unaligned_erms);
  99
 100   return OPTIMIZE1 (sse2_unaligned);
 101 }
 102
 103 libc_ifunc_redirected (__redirect___bzero, __bzero, IFUNC_SELECTOR ());
 104
 105 weak_alias (__bzero, bzero)
 106 #endif