forked from LadybirdBrowser/ladybird
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathEndian.h
More file actions
131 lines (107 loc) · 3.5 KB
/
Copy pathEndian.h
File metadata and controls
131 lines (107 loc) · 3.5 KB
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
/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Format.h>
#include <AK/Forward.h>
#include <AK/Platform.h>
namespace AK {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
inline constexpr static bool HostIsLittleEndian = true;
#else
inline constexpr static bool HostIsLittleEndian = false;
#endif
enum class Endianness {
Host,
Big,
Little,
};
template<typename T>
ALWAYS_INLINE constexpr T convert_between_host_and_little_endian(T value)
{
if constexpr (HostIsLittleEndian || sizeof(T) == 1)
return value;
else if constexpr (sizeof(T) == 8)
return static_cast<T>(__builtin_bswap64(static_cast<u64>(value)));
else if constexpr (sizeof(T) == 4)
return static_cast<T>(__builtin_bswap32(static_cast<u32>(value)));
else if constexpr (sizeof(T) == 2)
return static_cast<T>(__builtin_bswap16(static_cast<u16>(value)));
else
static_assert(DependentFalse<T>, "Cannot byte-swap values larger than 64-bits");
}
template<typename T>
ALWAYS_INLINE constexpr T convert_between_host_and_big_endian(T value)
{
if constexpr (sizeof(T) == 1 || !HostIsLittleEndian)
return value;
else if constexpr (sizeof(T) == 8)
return static_cast<T>(__builtin_bswap64(static_cast<u64>(value)));
else if constexpr (sizeof(T) == 4)
return static_cast<T>(__builtin_bswap32(static_cast<u32>(value)));
else if constexpr (sizeof(T) == 2)
return static_cast<T>(__builtin_bswap16(static_cast<u16>(value)));
else
static_assert(DependentFalse<T>, "Cannot byte-swap values larger than 64-bits");
}
template<typename T>
ALWAYS_INLINE T convert_between_host_and_network_endian(T value)
{
return convert_between_host_and_big_endian(value);
}
template<typename T>
class [[gnu::packed]] LittleEndian {
public:
constexpr LittleEndian() = default;
constexpr LittleEndian(T value)
: m_value(convert_between_host_and_little_endian(value))
{
}
constexpr operator T() const { return convert_between_host_and_little_endian(m_value); }
private:
T m_value { 0 };
};
template<typename T>
class [[gnu::packed]] BigEndian {
public:
constexpr BigEndian() = default;
constexpr BigEndian(T value)
: m_value(convert_between_host_and_big_endian(value))
{
}
constexpr operator T() const { return convert_between_host_and_big_endian(m_value); }
private:
T m_value { 0 };
};
template<typename T>
using NetworkOrdered = BigEndian<T>;
template<typename T>
requires(HasFormatter<T>) struct Formatter<LittleEndian<T>> : Formatter<T> {
};
template<typename T>
requires(HasFormatter<T>) struct Formatter<BigEndian<T>> : Formatter<T> {
};
template<typename T>
struct Traits<LittleEndian<T>> : public DefaultTraits<LittleEndian<T>> {
static constexpr bool is_trivially_serializable() { return Traits<T>::is_trivially_serializable(); }
};
template<typename T>
struct Traits<BigEndian<T>> : public DefaultTraits<BigEndian<T>> {
static constexpr bool is_trivially_serializable() { return Traits<T>::is_trivially_serializable(); }
};
constexpr u16 bitswap(u16 v)
{
v = ((v >> 1) & 0x5555) | ((v & 0x5555) << 1); // even & odd bits
v = ((v >> 2) & 0x3333) | ((v & 0x3333) << 2); // pairs
v = ((v >> 4) & 0x0F0F) | ((v & 0x0F0F) << 4); // nibbles
return ((v >> 8) & 0x00FF) | ((v & 0x00FF) << 8); // bytes
}
}
#if USING_AK_GLOBALLY
using AK::BigEndian;
using AK::bitswap;
using AK::LittleEndian;
using AK::NetworkOrdered;
#endif