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
_GLIBCXX_VISIBILITY(default)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
95