sysdeps/x86_64/multiarch/ifunc-evex.h

   1 /* Common definition for ifunc selection optimized with EVEX.
   2    All versions must be listed in ifunc-impl-list.c.
   3    Copyright (C) 2017-2023 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 extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_rtm) attribute_hidden;
  24
  25 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
  26 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
  27
  28 extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
  29
  30 static inline void *
  31 IFUNC_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 }