1  /* Architecture-specific glibc-hwcaps subdirectories.  x86 version.
       2     Copyright (C) 2020-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <dl-hwcaps.h>
      20  #include <cpu-features.h>
      21  #include <ldsodefs.h>
      22  #include <get-isa-level.h>
      23  
      24  const char _dl_hwcaps_subdirs[] = "x86-64-v4:x86-64-v3:x86-64-v2";
      25  enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
      26  
      27  uint32_t
      28  _dl_hwcaps_subdirs_active (void)
      29  {
      30    const struct cpu_features *cpu_features = __get_cpu_features ();
      31    unsigned int isa_level = get_isa_level (cpu_features);
      32    int active = 0;
      33  
      34    /* Test in reverse preference order.  */
      35  
      36    /* x86-64-v2.  */
      37    if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
      38      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
      39    ++active;
      40  
      41    /* x86-64-v3.  */
      42    if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
      43      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
      44    ++active;
      45  
      46    /* x86-64-v4.  */
      47    if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
      48      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
      49    ++active;
      50  
      51    return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
      52  }