sysdeps/x86/sys/platform/x86.h

   1 /* Data structure for x86 CPU features.
   2    This file is part of the GNU C Library.
   3    Copyright (C) 2008-2023 Free Software Foundation, Inc.
   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 #ifndef _SYS_PLATFORM_X86_H
  20 #define _SYS_PLATFORM_X86_H
  21
  22 #include <features.h>
  23 #include <stdbool.h>
  24 #include <bits/platform/x86.h>
  25
  26 __BEGIN_DECLS
  27
  28 /* Get a pointer to the CPU feature structure.  */
  29 extern const struct cpuid_feature *__x86_get_cpuid_feature_leaf (unsigned int)
  30      __attribute__ ((pure));
  31
  32 static __inline__ _Bool
  33 x86_cpu_present (unsigned int __index)
  34 {
  35   const struct cpuid_feature *__ptr = __x86_get_cpuid_feature_leaf
  36     (__index / (8 * sizeof (unsigned int) * 4));
  37   unsigned int __reg
  38      = __index & (8 * sizeof (unsigned int) * 4 - 1);
  39   unsigned int __bit = __reg & (8 * sizeof (unsigned int) - 1);
  40   __reg /= 8 * sizeof (unsigned int);
  41
  42   return __ptr->cpuid_array[__reg] & (1 << __bit);
  43 }
  44
  45 static __inline__ _Bool
  46 x86_cpu_active (unsigned int __index)
  47 {
  48   const struct cpuid_feature *__ptr = __x86_get_cpuid_feature_leaf
  49     (__index / (8 * sizeof (unsigned int) * 4));
  50   unsigned int __reg
  51      = __index & (8 * sizeof (unsigned int) * 4 - 1);
  52   unsigned int __bit = __reg & (8 * sizeof (unsigned int) - 1);
  53   __reg /= 8 * sizeof (unsigned int);
  54
  55   return __ptr->active_array[__reg] & (1 << __bit);
  56 }
  57
  58 /* CPU_FEATURE_PRESENT evaluates to true if CPU supports the feature.  */
  59 #define CPU_FEATURE_PRESENT(name) x86_cpu_present (x86_cpu_##name)
  60 /* CPU_FEATURE_ACTIVE evaluates to true if the feature is active.  */
  61 #define CPU_FEATURE_ACTIVE(name) x86_cpu_active (x86_cpu_##name)
  62
  63 __END_DECLS
  64
  65 #endif  /* _SYS_PLATFORM_X86_H */