sysdeps/mips/sys/tas.h

   1 /* Copyright (C) 2000-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_TAS_H
  19 #define _SYS_TAS_H 1
  20
  21 #include <features.h>
  22 #include <sgidefs.h>
  23
  24 __BEGIN_DECLS
  25
  26 extern int _test_and_set (int *__p, int __v)
  27      __THROW __attribute__ ((__nomips16__));
  28
  29 #ifdef __USE_EXTERN_INLINES
  30
  31 # ifndef _EXTERN_INLINE
  32 #  define _EXTERN_INLINE __extern_inline
  33 # endif
  34
  35 _EXTERN_INLINE int __attribute__ ((__nomips16__))
  36 __NTH (_test_and_set (int *__p, int __v))
  37 {
  38   int __r, __t;
  39
  40   /* The R5900 reports itself as MIPS III but it does not have LL/SC.  */
  41   __asm__ __volatile__
  42     ("/* Inline test and set */\n"
  43      ".set      push\n\t"
  44 #if _MIPS_SIM == _ABIO32 && (__mips < 2 || defined (_MIPS_ARCH_R5900))
  45      ".set      mips2\n\t"
  46 #endif
  47      "sync\n\t"
  48      "1:\n\t"
  49      "ll        %0,%3\n\t"
  50      "move      %1,%4\n\t"
  51      "beq       %0,%4,2f\n\t"
  52      "sc        %1,%2\n\t"
  53      "beqz      %1,1b\n"
  54      "sync\n\t"
  55      ".set      pop\n\t"
  56      "2:\n\t"
  57      "/* End test and set */"
  58      : "=&r" (__r), "=&r" (__t), "=m" (*__p)
  59      : "m" (*__p), "r" (__v)
  60      : "memory");
  61
  62   return __r;
  63 }
  64
  65 #endif /* __USE_EXTERN_INLINES */
  66
  67 __END_DECLS
  68
  69 #endif /* sys/tas.h */