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  }