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

   1 // Low-level functions for atomic operations: PA-RISC version  -*- C++ -*-
   2
   3 // Copyright (C) 2002-2018 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 <bits/c++config.h>
  26 #include <ext/atomicity.h>
  27
  28 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  29 {
  30 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  31
  32   template<int _Inst>
  33     struct _Atomicity_lock
  34     {
  35       static volatile int _S_atomicity_lock;
  36     };
  37
  38   template<int _Inst>
  39   volatile int
  40   _Atomicity_lock<_Inst>::_S_atomicity_lock __attribute__ ((aligned (16))) = 1;
  41
  42   // Because of the lack of weak support when using the hpux som
  43   // linker, we explicitly instantiate the atomicity lock.
  44   template volatile int _Atomicity_lock<0>::_S_atomicity_lock;
  45
  46   int
  47   __attribute__ ((__unused__))
  48   __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
  49   {
  50     _Atomic_word result;
  51     int tmp;
  52     volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock;
  53
  54     __asm__ __volatile__ ("ldcw 0(%1),%0\n\t"
  55                           "cmpib,<>,n 0,%0,.+20\n\t"
  56                           "ldw 0(%1),%0\n\t"
  57                           "cmpib,= 0,%0,.-4\n\t"
  58                           "nop\n\t"
  59                           "b,n .-20"
  60                           : "=&r" (tmp)
  61                           : "r" (&lock)
  62                           : "memory");
  63
  64     result = *__mem;
  65     *__mem = result + __val;
  66     __asm__ __volatile__ ("stw %1,0(%0)"
  67                           : : "r" (&lock), "r" (tmp) : "memory");
  68     return result;
  69   }
  70
  71   void
  72   __attribute__ ((__unused__))
  73   __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
  74   {
  75     int tmp;
  76     volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock;
  77
  78     __asm__ __volatile__ ("ldcw 0(%1),%0\n\t"
  79                           "cmpib,<>,n 0,%0,.+20\n\t"
  80                           "ldw 0(%1),%0\n\t"
  81                           "cmpib,= 0,%0,.-4\n\t"
  82                           "nop\n\t"
  83                           "b,n .-20"
  84                           : "=&r" (tmp)
  85                           : "r" (&lock)
  86                           : "memory");
  87
  88     *__mem += __val;
  89     __asm__ __volatile__ ("stw %1,0(%0)"
  90                           : : "r" (&lock), "r" (tmp) : "memory");
  91   }
  92
  93 _GLIBCXX_END_NAMESPACE_VERSION
  94 } // namespace