1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
/*
* Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef WTF_Alignment_h
#define WTF_Alignment_h
#include "wtf/Compiler.h"
#include <algorithm>
#include <stdint.h>
#include <utility>
namespace WTF {
#if COMPILER(GCC)
#define WTF_ALIGN_OF(type) __alignof__(type)
#define WTF_ALIGNED(variable_type, variable, n) \
variable_type variable __attribute__((__aligned__(n)))
#elif COMPILER(MSVC)
#define WTF_ALIGN_OF(type) __alignof(type)
#define WTF_ALIGNED(variable_type, variable, n) \
__declspec(align(n)) variable_type variable
#else
#error WTF_ALIGN macros need alignment control.
#endif
#if COMPILER(GCC)
typedef char __attribute__((__may_alias__)) AlignedBufferChar;
#else
typedef char AlignedBufferChar;
#endif
template <size_t size, size_t alignment>
struct AlignedBuffer;
template <size_t size>
struct AlignedBuffer<size, 1> {
AlignedBufferChar buffer[size];
};
template <size_t size>
struct AlignedBuffer<size, 2> {
WTF_ALIGNED(AlignedBufferChar, buffer[size], 2);
};
template <size_t size>
struct AlignedBuffer<size, 4> {
WTF_ALIGNED(AlignedBufferChar, buffer[size], 4);
};
template <size_t size>
struct AlignedBuffer<size, 8> {
WTF_ALIGNED(AlignedBufferChar, buffer[size], 8);
};
template <size_t size>
struct AlignedBuffer<size, 16> {
WTF_ALIGNED(AlignedBufferChar, buffer[size], 16);
};
template <size_t size>
struct AlignedBuffer<size, 32> {
WTF_ALIGNED(AlignedBufferChar, buffer[size], 32);
};
template <size_t size>
struct AlignedBuffer<size, 64> {
WTF_ALIGNED(AlignedBufferChar, buffer[size], 64);
};
template <size_t size, size_t alignment>
void swap(AlignedBuffer<size, alignment>& a,
AlignedBuffer<size, alignment>& b) {
for (size_t i = 0; i < size; ++i)
std::swap(a.buffer[i], b.buffer[i]);
}
template <uintptr_t mask>
inline bool isAlignedTo(const void* pointer) {
return !(reinterpret_cast<uintptr_t>(pointer) & mask);
}
} // namespace WTF
#endif // WTF_Alignment_h
|
