atomicity.h revision 1.1.1.1.8.1 
1// Low-level functions for atomic operations: Sparc version  -*- C++ -*-
2
3// Copyright (C) 1999-2013 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
27namespace __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