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
| //===- SwapByteOrder.h - Generic and optimized byte swaps -------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file declares generic and optimized functions to swap the byte order of
// an integral type.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_SWAPBYTEORDER_H
#define LLVM_SUPPORT_SWAPBYTEORDER_H
#include "llvm/Support/Compiler.h"
#include "llvm/Support/DataTypes.h"
#include <cstddef>
#include <type_traits>
#if defined(_MSC_VER) && !defined(_DEBUG)
#include <stdlib.h>
#endif
#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__)
#include <endian.h>
#elif defined(_AIX)
#include <sys/machine.h>
#elif defined(__sun)
/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
#include <sys/types.h>
#define BIG_ENDIAN 4321
#define LITTLE_ENDIAN 1234
#if defined(_BIG_ENDIAN)
#define BYTE_ORDER BIG_ENDIAN
#else
#define BYTE_ORDER LITTLE_ENDIAN
#endif
#else
#if !defined(BYTE_ORDER) && !defined(_WIN32)
#include <machine/endian.h>
#endif
#endif
namespace llvm {
namespace sys {
#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
constexpr bool IsBigEndianHost = true;
#else
constexpr bool IsBigEndianHost = false;
#endif
static const bool IsLittleEndianHost = !IsBigEndianHost;
/// SwapByteOrder_16 - This function returns a byte-swapped representation of
/// the 16-bit argument.
inline uint16_t SwapByteOrder_16(uint16_t value) {
#if defined(_MSC_VER) && !defined(_DEBUG)
// The DLL version of the runtime lacks these functions (bug!?), but in a
// release build they're replaced with BSWAP instructions anyway.
return _byteswap_ushort(value);
#else
uint16_t Hi = value << 8;
uint16_t Lo = value >> 8;
return Hi | Lo;
#endif
}
/// This function returns a byte-swapped representation of the 32-bit argument.
inline uint32_t SwapByteOrder_32(uint32_t value) {
#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC))
return __builtin_bswap32(value);
#elif defined(_MSC_VER) && !defined(_DEBUG)
return _byteswap_ulong(value);
#else
uint32_t Byte0 = value & 0x000000FF;
uint32_t Byte1 = value & 0x0000FF00;
uint32_t Byte2 = value & 0x00FF0000;
uint32_t Byte3 = value & 0xFF000000;
return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24);
#endif
}
/// This function returns a byte-swapped representation of the 64-bit argument.
inline uint64_t SwapByteOrder_64(uint64_t value) {
#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC))
return __builtin_bswap64(value);
#elif defined(_MSC_VER) && !defined(_DEBUG)
return _byteswap_uint64(value);
#else
uint64_t Hi = SwapByteOrder_32(uint32_t(value));
uint32_t Lo = SwapByteOrder_32(uint32_t(value >> 32));
return (Hi << 32) | Lo;
#endif
}
inline unsigned char getSwappedBytes(unsigned char C) { return C; }
inline signed char getSwappedBytes(signed char C) { return C; }
inline char getSwappedBytes(char C) { return C; }
inline unsigned short getSwappedBytes(unsigned short C) { return SwapByteOrder_16(C); }
inline signed short getSwappedBytes( signed short C) { return SwapByteOrder_16(C); }
inline unsigned int getSwappedBytes(unsigned int C) { return SwapByteOrder_32(C); }
inline signed int getSwappedBytes( signed int C) { return SwapByteOrder_32(C); }
#if __LONG_MAX__ == __INT_MAX__
inline unsigned long getSwappedBytes(unsigned long C) { return SwapByteOrder_32(C); }
inline signed long getSwappedBytes( signed long C) { return SwapByteOrder_32(C); }
#elif __LONG_MAX__ == __LONG_LONG_MAX__
inline unsigned long getSwappedBytes(unsigned long C) { return SwapByteOrder_64(C); }
inline signed long getSwappedBytes( signed long C) { return SwapByteOrder_64(C); }
#else
#error "Unknown long size!"
#endif
inline unsigned long long getSwappedBytes(unsigned long long C) {
return SwapByteOrder_64(C);
}
inline signed long long getSwappedBytes(signed long long C) {
return SwapByteOrder_64(C);
}
inline float getSwappedBytes(float C) {
union {
uint32_t i;
float f;
} in, out;
in.f = C;
out.i = SwapByteOrder_32(in.i);
return out.f;
}
inline double getSwappedBytes(double C) {
union {
uint64_t i;
double d;
} in, out;
in.d = C;
out.i = SwapByteOrder_64(in.i);
return out.d;
}
template <typename T>
inline typename std::enable_if<std::is_enum<T>::value, T>::type
getSwappedBytes(T C) {
return static_cast<T>(
getSwappedBytes(static_cast<typename std::underlying_type<T>::type>(C)));
}
template<typename T>
inline void swapByteOrder(T &Value) {
Value = getSwappedBytes(Value);
}
} // end namespace sys
} // end namespace llvm
#endif
|