sysdeps/x86/nptl/thread_pointer.h

   1 /* __thread_pointer definition.  x86 version.
   2    Copyright (C) 2021-2024 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 #ifndef _SYS_THREAD_POINTER_H
  20 #define _SYS_THREAD_POINTER_H
  21
  22 static inline void *
  23 __thread_pointer (void)
  24 {
  25 #if __GNUC_PREREQ (11, 1)
  26   return __builtin_thread_pointer ();
  27 #else
  28   void *__result;
  29 # ifdef __x86_64__
  30   __asm__ ("mov %%fs:0, %0" : "=r" (__result));
  31 # else
  32   __asm__ ("mov %%gs:0, %0" : "=r" (__result));
  33 # endif
  34   return __result;
  35 #endif /* !GCC 11 */
  36 }
  37
  38 #endif /* _SYS_THREAD_POINTER_H */