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

   1 // Low-level functions for atomic operations: PA-RISC version  -*- C++ -*-
   2
   3 // Copyright (C) 2002-2022 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 /* Perform ldcw operation in cache when possible.  */
  29 #ifndef _PA_LDCW_INSN
  30 # ifdef _PA_RISC2_0
  31 # define _PA_LDCW_INSN "ldcw,co"
  32 # else
  33 # define _PA_LDCW_INSN "ldcw"
  34 # endif
  35 #endif
  36
  37 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  38 {
  39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  40
  41   template<int _Inst>
  42     struct _Atomicity_lock
  43     {
  44       static volatile int _S_atomicity_lock;
  45     };
  46
  47   template<int _Inst>
  48   volatile int
  49   _Atomicity_lock<_Inst>::_S_atomicity_lock __attribute__ ((aligned (16))) = 1;
  50
  51   // Because of the lack of weak support when using the hpux som
  52   // linker, we explicitly instantiate the atomicity lock.
  53   template volatile int _Atomicity_lock<0>::_S_atomicity_lock;
  54
  55   int
  56   __attribute__ ((__unused__))
  57   __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
  58   {
  59     _Atomic_word result;
  60     int tmp;
  61     volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock;
  62
  63     __asm__ __volatile__ (_PA_LDCW_INSN " 0(%1),%0\n\t"
  64                           "cmpib,<>,n 0,%0,.+20\n\t"
  65                           "ldw,ma 0(%1),%0\n\t"
  66                           "cmpib,<> 0,%0,.-12\n\t"
  67                           "nop\n\t"
  68                           "b,n .-12"
  69                           : "=&r" (tmp)
  70                           : "r" (&lock)
  71                           : "memory");
  72
  73     result = *__mem;
  74     *__mem = result + __val;
  75     __asm__ __volatile__ ("stw,ma %1,0(%0)"
  76                           : : "r" (&lock), "r" (tmp) : "memory");
  77     return result;
  78   }
  79
  80   void
  81   __attribute__ ((__unused__))
  82   __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
  83   {
  84     int tmp;
  85     volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock;
  86
  87     __asm__ __volatile__ (_PA_LDCW_INSN " 0(%1),%0\n\t"
  88                           "cmpib,<>,n 0,%0,.+20\n\t"
  89                           "ldw,ma 0(%1),%0\n\t"
  90                           "cmpib,<> 0,%0,.-12\n\t"
  91                           "nop\n\t"
  92                           "b,n .-12"
  93                           : "=&r" (tmp)
  94                           : "r" (&lock)
  95                           : "memory");
  96
  97     *__mem += __val;
  98     __asm__ __volatile__ ("stw,ma %1,0(%0)"
  99                           : : "r" (&lock), "r" (tmp) : "memory");
 100   }
 101
 102 _GLIBCXX_END_NAMESPACE_VERSION
 103 } // namespace