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