sysdeps/unix/sysv/linux/mips/sys/tas.h

   1 /* Copyright (C) 2000, 2002, 2003, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Maciej W. Rozycki <macro@ds2.pg.gda.pl>, 2000.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _SYS_TAS_H
  21 #define _SYS_TAS_H 1
  22
  23 #include <features.h>
  24 #include <sgidefs.h>
  25
  26 __BEGIN_DECLS
  27
  28 extern int _test_and_set (int *p, int v) __THROW;
  29
  30 #ifdef __USE_EXTERN_INLINES
  31
  32 # ifndef _EXTERN_INLINE
  33 #  define _EXTERN_INLINE extern __inline
  34 # endif
  35
  36 _EXTERN_INLINE int
  37 __NTH (_test_and_set (int *p, int v))
  38 {
  39   int r, t;
  40
  41   __asm__ __volatile__
  42     ("/* Inline test and set */\n"
  43      "1:\n\t"
  44      ".set      push\n\t"
  45 #if _MIPS_SIM == _ABIO32
  46      ".set      mips2\n\t"
  47 #endif
  48      "ll        %0,%3\n\t"
  49      "move      %1,%4\n\t"
  50      "beq       %0,%4,2f\n\t"
  51      "sc        %1,%2\n\t"
  52      ".set      pop\n\t"
  53      "beqz      %1,1b\n"
  54      "2:\n\t"
  55      "/* End test and set */"
  56      : "=&r" (r), "=&r" (t), "=m" (*p)
  57      : "m" (*p), "r" (v)
  58      : "memory");
  59
  60   return r;
  61 }
  62
  63 #endif /* __USE_EXTERN_INLINES */
  64
  65 __END_DECLS
  66
  67 #endif /* sys/tas.h */