atomicity.h (__compare_and_swap): Remove unused function.
[gcc.git] / libstdc++-v3 / config / cpu / alpha / bits / atomicity.h
1 // Low-level functions for atomic operations: Alpha version -*- C++ -*-
2
3 // Copyright (C) 1999, 2000, 2001 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 2, 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 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING. If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19 // USA.
20
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
29
30 #ifndef _BITS_ATOMICITY_H
31 #define _BITS_ATOMICITY_H 1
32
33 /* @@@ With gas we can play nice .subsection games to get the
34 non-predicted branch pointing forward. But Digital assemblers
35 don't understand those directives. This isn't a terribly
36 important issue, so just ignore it. */
37
38 typedef int _Atomic_word;
39
40 static inline _Atomic_word
41 __attribute__ ((__unused__))
42 __exchange_and_add (volatile _Atomic_word* __mem, int __val)
43 {
44 register int __result, __tmp;
45
46 __asm__ __volatile__ (
47 "\n$Lxadd_%=:\n\t"
48 "ldl_l %0,%3\n\t"
49 "addl %0,%4,%1\n\t"
50 "stl_c %1,%2\n\t"
51 "beq %1,$Lxadd_%=\n\t"
52 "mb"
53 : "=&r"(__result), "=&r"(__tmp), "=m"(*__mem)
54 : "m" (*__mem), "r"(__val));
55
56 return __result;
57 }
58
59 static inline void
60 __attribute__ ((__unused__))
61 __atomic_add (volatile _Atomic_word* __mem, int __val)
62 {
63 register _Atomic_word __result;
64
65 __asm__ __volatile__ (
66 "\n$Ladd_%=:\n\t"
67 "ldl_l %0,%2\n\t"
68 "addl %0,%3,%0\n\t"
69 "stl_c %0,%1\n\t"
70 "beq %0,$Ladd_%=\n\t"
71 "mb"
72 : "=&r"(__result), "=m"(*__mem)
73 : "m" (*__mem), "r"(__val));
74 }
75
76 #endif /* atomicity.h */