libstdc++-v3/config/cpu/sparc/atomicity.h

   1 // Low-level functions for atomic operations: Sparc version  -*- C++ -*-
   2
   3 // Copyright (C) 1999-2019 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 #include <ext/atomicity.h>
  26
  27 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  28 {
  29 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  30
  31 #ifdef __arch64__
  32   _Atomic_word
  33   __attribute__ ((__unused__))
  34   __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
  35   {
  36     _Atomic_word __tmp1, __tmp2;
  37     _Atomic_word __val_extended = __val;
  38
  39     __asm__ __volatile__("1:    ldx     [%3], %0\n\t"
  40                          "      add     %0, %4, %1\n\t"
  41                          "      casx    [%3], %0, %1\n\t"
  42                          "      sub     %0, %1, %0\n\t"
  43                          "      brnz,pn %0, 1b\n\t"
  44                          "       nop"
  45                          : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)
  46                          : "r" (__mem), "r" (__val_extended), "m" (*__mem));
  47     return __tmp2;
  48   }
  49
  50   void
  51   __attribute__ ((__unused__))
  52   __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
  53   {
  54     _Atomic_word __tmp1, __tmp2;
  55     _Atomic_word __val_extended = __val;
  56
  57     __asm__ __volatile__("1:    ldx     [%3], %0\n\t"
  58                          "      add     %0, %4, %1\n\t"
  59                          "      casx    [%3], %0, %1\n\t"
  60                          "      sub     %0, %1, %0\n\t"
  61                          "      brnz,pn %0, 1b\n\t"
  62                          "       nop"
  63                          : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)
  64                          : "r" (__mem), "r" (__val_extended), "m" (*__mem));
  65   }
  66
  67 #else /* __arch32__ */
  68
  69   template<int __inst>
  70     struct _Atomicity_lock
  71     {
  72       static unsigned char _S_atomicity_lock;
  73     };
  74
  75   template<int __inst>
  76   unsigned char _Atomicity_lock<__inst>::_S_atomicity_lock = 0;
  77
  78   template unsigned char _Atomicity_lock<0>::_S_atomicity_lock;
  79
  80   _Atomic_word
  81   __attribute__ ((__unused__))
  82   __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
  83   {
  84     _Atomic_word __result, __tmp;
  85
  86     __asm__ __volatile__("1:    ldstub  [%1], %0\n\t"
  87                          "      cmp     %0, 0\n\t"
  88                          "      bne     1b\n\t"
  89                          "       nop"
  90                          : "=&r" (__tmp)
  91                          : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
  92                          : "memory");
  93     __result = *__mem;
  94     *__mem += __val;
  95     __asm__ __volatile__("stb   %%g0, [%0]"
  96                          : /* no outputs */
  97                          : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
  98                          : "memory");
  99     return __result;
 100   }
 101
 102   void
 103   __attribute__ ((__unused__))
 104   __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
 105   {
 106     _Atomic_word __tmp;
 107
 108     __asm__ __volatile__("1:    ldstub  [%1], %0\n\t"
 109                          "      cmp     %0, 0\n\t"
 110                          "      bne     1b\n\t"
 111                          "       nop"
 112                          : "=&r" (__tmp)
 113                          : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
 114                          : "memory");
 115     *__mem += __val;
 116     __asm__ __volatile__("stb   %%g0, [%0]"
 117                          : /* no outputs */
 118                          : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
 119                          : "memory");
 120   }
 121 #endif /* __arch32__ */
 122
 123 _GLIBCXX_END_NAMESPACE_VERSION
 124 } // namespace