1 // Low-level functions for atomic operations: Sparc version -*- C++ -*-
2
3 // Copyright (C) 1999-2020 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
_GLIBCXX_VISIBILITY(default)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
125