atomicity.h revision 1.1 
1// Low-level functions for atomic operations: Sparc version  -*- C++ -*-
2
3// Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2009
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 3, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
24// <http://www.gnu.org/licenses/>.
25
26#include <ext/atomicity.h>
27
28_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
29
30#ifdef __arch64__
31  _Atomic_word
32  __attribute__ ((__unused__))
33  __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
34  {
35    _Atomic_word __tmp1, __tmp2;
36    _Atomic_word __val_extended = __val;
37
38    __asm__ __volatile__("1:	ldx	[%3], %0\n\t"
39			 "	add	%0, %4, %1\n\t"
40			 "	casx	[%3], %0, %1\n\t"
41			 "	sub	%0, %1, %0\n\t"
42			 "	brnz,pn	%0, 1b\n\t"
43			 "	 nop"
44			 : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)
45			 : "r" (__mem), "r" (__val_extended), "m" (*__mem));
46    return __tmp2;
47  }
48
49  void
50  __attribute__ ((__unused__))
51  __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
52  {
53    _Atomic_word __tmp1, __tmp2;
54    _Atomic_word __val_extended = __val;
55
56    __asm__ __volatile__("1:	ldx	[%3], %0\n\t"
57			 "	add	%0, %4, %1\n\t"
58			 "	casx	[%3], %0, %1\n\t"
59			 "	sub	%0, %1, %0\n\t"
60			 "	brnz,pn	%0, 1b\n\t"
61			 "	 nop"
62			 : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)
63			 : "r" (__mem), "r" (__val_extended), "m" (*__mem));
64  }
65
66#else /* __arch32__ */
67
68  template<int __inst>
69    struct _Atomicity_lock
70    {
71      static unsigned char _S_atomicity_lock;
72    };
73
74  template<int __inst>
75  unsigned char _Atomicity_lock<__inst>::_S_atomicity_lock = 0;
76
77  template unsigned char _Atomicity_lock<0>::_S_atomicity_lock;
78
79  _Atomic_word
80  __attribute__ ((__unused__))
81  __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
82  {
83    _Atomic_word __result, __tmp;
84
85    __asm__ __volatile__("1:	ldstub	[%1], %0\n\t"
86			 "	cmp	%0, 0\n\t"
87			 "	bne	1b\n\t"
88			 "	 nop"
89			 : "=&r" (__tmp)
90			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
91			 : "memory");
92    __result = *__mem;
93    *__mem += __val;
94    __asm__ __volatile__("stb	%%g0, [%0]"
95			 : /* no outputs */
96			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
97			 : "memory");
98    return __result;
99  }
100
101  void
102  __attribute__ ((__unused__))
103  __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
104  {
105    _Atomic_word __tmp;
106
107    __asm__ __volatile__("1:	ldstub	[%1], %0\n\t"
108			 "	cmp	%0, 0\n\t"
109			 "	bne	1b\n\t"
110			 "	 nop"
111			 : "=&r" (__tmp)
112			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
113			 : "memory");
114    *__mem += __val;
115    __asm__ __volatile__("stb	%%g0, [%0]"
116			 : /* no outputs */
117			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
118			 : "memory");
119  }
120#endif /* __arch32__ */
121
122_GLIBCXX_END_NAMESPACE
123