1// Low-level functions for atomic operations: Sparc version  -*- C++ -*-
2
3// Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005
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 2, 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// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31#include <ext/atomicity.h>
32
33_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
34
35#ifdef __arch64__
36  _Atomic_word
37  __attribute__ ((__unused__))
38  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
39  {
40    _Atomic_word __tmp1, __tmp2;
41    _Atomic_word __val_extended = __val;
42
43    __asm__ __volatile__("1:	ldx	[%3], %0\n\t"
44			 "	add	%0, %4, %1\n\t"
45			 "	casx	[%3], %0, %1\n\t"
46			 "	sub	%0, %1, %0\n\t"
47			 "	brnz,pn	%0, 1b\n\t"
48			 "	 nop"
49			 : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)
50			 : "r" (__mem), "r" (__val_extended), "m" (*__mem));
51    return __tmp2;
52  }
53
54  void
55  __attribute__ ((__unused__))
56  __atomic_add(volatile _Atomic_word* __mem, int __val)
57  {
58    _Atomic_word __tmp1, __tmp2;
59    _Atomic_word __val_extended = __val;
60
61    __asm__ __volatile__("1:	ldx	[%3], %0\n\t"
62			 "	add	%0, %4, %1\n\t"
63			 "	casx	[%3], %0, %1\n\t"
64			 "	sub	%0, %1, %0\n\t"
65			 "	brnz,pn	%0, 1b\n\t"
66			 "	 nop"
67			 : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)
68			 : "r" (__mem), "r" (__val_extended), "m" (*__mem));
69  }
70
71#else /* __arch32__ */
72
73  template<int __inst>
74    struct _Atomicity_lock
75    {
76      static unsigned char _S_atomicity_lock;
77    };
78
79  template<int __inst>
80  unsigned char _Atomicity_lock<__inst>::_S_atomicity_lock = 0;
81
82  template unsigned char _Atomicity_lock<0>::_S_atomicity_lock;
83
84  _Atomic_word
85  __attribute__ ((__unused__))
86  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
87  {
88    _Atomic_word __result, __tmp;
89
90    __asm__ __volatile__("1:	ldstub	[%1], %0\n\t"
91			 "	cmp	%0, 0\n\t"
92			 "	bne	1b\n\t"
93			 "	 nop"
94			 : "=&r" (__tmp)
95			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
96			 : "memory");
97    __result = *__mem;
98    *__mem += __val;
99    __asm__ __volatile__("stb	%%g0, [%0]"
100			 : /* no outputs */
101			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
102			 : "memory");
103    return __result;
104  }
105
106  void
107  __attribute__ ((__unused__))
108  __atomic_add(volatile _Atomic_word* __mem, int __val)
109  {
110    _Atomic_word __tmp;
111
112    __asm__ __volatile__("1:	ldstub	[%1], %0\n\t"
113			 "	cmp	%0, 0\n\t"
114			 "	bne	1b\n\t"
115			 "	 nop"
116			 : "=&r" (__tmp)
117			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
118			 : "memory");
119    *__mem += __val;
120    __asm__ __volatile__("stb	%%g0, [%0]"
121			 : /* no outputs */
122			 : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)
123			 : "memory");
124  }
125#endif /* __arch32__ */
126
127_GLIBCXX_END_NAMESPACE
128