sysdeps/x86_64/multiarch/ifunc-strncpy.h

   1 /* Common definition for ifunc st{r|p}n{cpy|cat}
   2    All versions must be listed in ifunc-impl-list.c.
   3    Copyright (C) 2022-2024 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
  22 extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
  23
  24 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
  25 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
  26
  27 extern __typeof (REDIRECT_NAME)
  28     OPTIMIZE (sse2_unaligned) attribute_hidden;
  29
  30 static inline void *
  31 IFUNC_SELECTOR (void)
  32 {
  33   const struct cpu_features *cpu_features = __get_cpu_features ();
  34
  35   if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2)
  36       && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
  37                                       AVX_Fast_Unaligned_Load, ))
  38     {
  39       if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
  40           && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
  41         return OPTIMIZE (evex);
  42
  43       if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
  44         return OPTIMIZE (avx2_rtm);
  45
  46       if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
  47                                        Prefer_No_VZEROUPPER, !))
  48         return OPTIMIZE (avx2);
  49     }
  50
  51   return OPTIMIZE (sse2_unaligned);
  52 }