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

   1 /* Copyright (C) 2000, 2002 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
  25 __BEGIN_DECLS
  26
  27 extern int _test_and_set (int *p, int v) __THROW;
  28
  29 #ifdef __USE_EXTERN_INLINES
  30
  31 # ifndef _EXTERN_INLINE
  32 #  define _EXTERN_INLINE extern __inline
  33 # endif
  34
  35 _EXTERN_INLINE int
  36 _test_and_set (int *p, int v) __THROW
  37 {
  38   int r, t;
  39
  40   __asm__ __volatile__
  41     ("/* Inline test and set */\n"
  42      "1:\n\t"
  43      ".set      push\n\t"
  44      ".set      mips2\n\t"
  45      "ll        %0,%3\n\t"
  46      "move      %1,%4\n\t"
  47      "beq       %0,%4,2f\n\t"
  48      "sc        %1,%2\n\t"
  49      ".set      pop\n\t"
  50      "beqz      %1,1b\n"
  51      "2:\n\t"
  52      "/* End test and set */"
  53      : "=&r" (r), "=&r" (t), "=m" (*p)
  54      : "m" (*p), "r" (v)
  55      : "memory");
  56
  57   return r;
  58 }
  59
  60 #endif /* __USE_EXTERN_INLINES */
  61
  62 __END_DECLS
  63
  64 #endif /* sys/tas.h */