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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
//===- Endian.h - Utilities for IO with endian specific data ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares generic functions to read and write endian specific data.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_ENDIAN_H
#define LLVM_SUPPORT_ENDIAN_H
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/SwapByteOrder.h"
namespace llvm {
namespace support {
enum endianness {big, little, native};
// These are named values for common alignments.
enum {aligned = 0, unaligned = 1};
namespace detail {
/// \brief ::value is either alignment, or alignof(T) if alignment is 0.
template<class T, int alignment>
struct PickAlignment {
enum {value = alignment == 0 ? AlignOf<T>::Alignment : alignment};
};
} // end namespace detail
namespace endian {
/// Swap the bytes of value to match the given endianness.
template<typename value_type, endianness endian>
inline value_type byte_swap(value_type value) {
if (endian != native && sys::IsBigEndianHost != (endian == big))
sys::swapByteOrder(value);
return value;
}
/// Read a value of a particular endianness from memory.
template<typename value_type,
endianness endian,
std::size_t alignment>
inline value_type read(const void *memory) {
value_type ret;
memcpy(&ret,
LLVM_ASSUME_ALIGNED(memory,
(detail::PickAlignment<value_type, alignment>::value)),
sizeof(value_type));
return byte_swap<value_type, endian>(ret);
}
/// Read a value of a particular endianness from a buffer, and increment the
/// buffer past that value.
template<typename value_type, endianness endian, std::size_t alignment>
inline value_type readNext(const unsigned char *&memory) {
value_type ret = read<value_type, endian, alignment>(memory);
memory += sizeof(value_type);
return ret;
}
/// Write a value to memory with a particular endianness.
template<typename value_type,
endianness endian,
std::size_t alignment>
inline void write(void *memory, value_type value) {
value = byte_swap<value_type, endian>(value);
memcpy(LLVM_ASSUME_ALIGNED(memory,
(detail::PickAlignment<value_type, alignment>::value)),
&value,
sizeof(value_type));
}
} // end namespace endian
namespace detail {
template<typename value_type,
endianness endian,
std::size_t alignment>
struct packed_endian_specific_integral {
operator value_type() const {
return endian::read<value_type, endian, alignment>(
(const void*)Value.buffer);
}
void operator=(value_type newValue) {
endian::write<value_type, endian, alignment>(
(void*)Value.buffer, newValue);
}
packed_endian_specific_integral &operator+=(value_type newValue) {
*this = *this + newValue;
return *this;
}
packed_endian_specific_integral &operator-=(value_type newValue) {
*this = *this - newValue;
return *this;
}
private:
AlignedCharArray<PickAlignment<value_type, alignment>::value,
sizeof(value_type)> Value;
public:
struct ref {
explicit ref(void *Ptr) : Ptr(Ptr) {}
operator value_type() const {
return endian::read<value_type, endian, alignment>(Ptr);
}
void operator=(value_type NewValue) {
endian::write<value_type, endian, alignment>(Ptr, NewValue);
}
private:
void *Ptr;
};
};
} // end namespace detail
typedef detail::packed_endian_specific_integral
<uint16_t, little, unaligned> ulittle16_t;
typedef detail::packed_endian_specific_integral
<uint32_t, little, unaligned> ulittle32_t;
typedef detail::packed_endian_specific_integral
<uint64_t, little, unaligned> ulittle64_t;
typedef detail::packed_endian_specific_integral
<int16_t, little, unaligned> little16_t;
typedef detail::packed_endian_specific_integral
<int32_t, little, unaligned> little32_t;
typedef detail::packed_endian_specific_integral
<int64_t, little, unaligned> little64_t;
typedef detail::packed_endian_specific_integral
<uint16_t, little, aligned> aligned_ulittle16_t;
typedef detail::packed_endian_specific_integral
<uint32_t, little, aligned> aligned_ulittle32_t;
typedef detail::packed_endian_specific_integral
<uint64_t, little, aligned> aligned_ulittle64_t;
typedef detail::packed_endian_specific_integral
<int16_t, little, aligned> aligned_little16_t;
typedef detail::packed_endian_specific_integral
<int32_t, little, aligned> aligned_little32_t;
typedef detail::packed_endian_specific_integral
<int64_t, little, aligned> aligned_little64_t;
typedef detail::packed_endian_specific_integral
<uint16_t, big, unaligned> ubig16_t;
typedef detail::packed_endian_specific_integral
<uint32_t, big, unaligned> ubig32_t;
typedef detail::packed_endian_specific_integral
<uint64_t, big, unaligned> ubig64_t;
typedef detail::packed_endian_specific_integral
<int16_t, big, unaligned> big16_t;
typedef detail::packed_endian_specific_integral
<int32_t, big, unaligned> big32_t;
typedef detail::packed_endian_specific_integral
<int64_t, big, unaligned> big64_t;
typedef detail::packed_endian_specific_integral
<uint16_t, big, aligned> aligned_ubig16_t;
typedef detail::packed_endian_specific_integral
<uint32_t, big, aligned> aligned_ubig32_t;
typedef detail::packed_endian_specific_integral
<uint64_t, big, aligned> aligned_ubig64_t;
typedef detail::packed_endian_specific_integral
<int16_t, big, aligned> aligned_big16_t;
typedef detail::packed_endian_specific_integral
<int32_t, big, aligned> aligned_big32_t;
typedef detail::packed_endian_specific_integral
<int64_t, big, aligned> aligned_big64_t;
typedef detail::packed_endian_specific_integral
<uint16_t, native, unaligned> unaligned_uint16_t;
typedef detail::packed_endian_specific_integral
<uint32_t, native, unaligned> unaligned_uint32_t;
typedef detail::packed_endian_specific_integral
<uint64_t, native, unaligned> unaligned_uint64_t;
typedef detail::packed_endian_specific_integral
<int16_t, native, unaligned> unaligned_int16_t;
typedef detail::packed_endian_specific_integral
<int32_t, native, unaligned> unaligned_int32_t;
typedef detail::packed_endian_specific_integral
<int64_t, native, unaligned> unaligned_int64_t;
} // end namespace llvm
} // end namespace support
#endif
|
