LLVM 17.0.0git
SwapByteOrder.h
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1//===- SwapByteOrder.h - Generic and optimized byte swaps -------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file declares generic and optimized functions to swap the byte order of
10// an integral type.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_SWAPBYTEORDER_H
15#define LLVM_SUPPORT_SWAPBYTEORDER_H
16
17#include "llvm/ADT/bit.h"
18#include <cstddef>
19#include <cstdint>
20#include <type_traits>
21
22#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__) || \
23 defined(__Fuchsia__) || defined(__EMSCRIPTEN__)
24#include <endian.h>
25#elif defined(_AIX)
26#include <sys/machine.h>
27#elif defined(__sun)
28/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
29#include <sys/types.h>
30#define BIG_ENDIAN 4321
31#define LITTLE_ENDIAN 1234
32#if defined(_BIG_ENDIAN)
33#define BYTE_ORDER BIG_ENDIAN
34#else
35#define BYTE_ORDER LITTLE_ENDIAN
36#endif
37#elif defined(__MVS__)
38#define BIG_ENDIAN 4321
39#define LITTLE_ENDIAN 1234
40#define BYTE_ORDER BIG_ENDIAN
41#else
42#if !defined(BYTE_ORDER) && !defined(_WIN32)
43#include <machine/endian.h>
44#endif
45#endif
46
47namespace llvm {
48
49/// ByteSwap_16 - This function returns a byte-swapped representation of
50/// the 16-bit argument.
52
53/// This function returns a byte-swapped representation of the 32-bit argument.
55
56/// This function returns a byte-swapped representation of the 64-bit argument.
58
59namespace sys {
60
61#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
62constexpr bool IsBigEndianHost = true;
63#else
64constexpr bool IsBigEndianHost = false;
65#endif
66
68
69inline unsigned char getSwappedBytes(unsigned char C) { return llvm::byteswap(C); }
70inline signed char getSwappedBytes( signed char C) { return llvm::byteswap(C); }
71inline char getSwappedBytes( char C) { return llvm::byteswap(C); }
72
73inline unsigned short getSwappedBytes(unsigned short C) { return llvm::byteswap(C); }
74inline signed short getSwappedBytes( signed short C) { return llvm::byteswap(C); }
75
76inline unsigned int getSwappedBytes(unsigned int C) { return llvm::byteswap(C); }
77inline signed int getSwappedBytes( signed int C) { return llvm::byteswap(C); }
78
79inline unsigned long getSwappedBytes(unsigned long C) { return llvm::byteswap(C); }
80inline signed long getSwappedBytes( signed long C) { return llvm::byteswap(C); }
81
82inline unsigned long long getSwappedBytes(unsigned long long C) { return llvm::byteswap(C); }
83inline signed long long getSwappedBytes( signed long long C) { return llvm::byteswap(C); }
84
85inline float getSwappedBytes(float C) {
86 union {
87 uint32_t i;
88 float f;
89 } in, out;
90 in.f = C;
91 out.i = llvm::byteswap(in.i);
92 return out.f;
93}
94
95inline double getSwappedBytes(double C) {
96 union {
97 uint64_t i;
98 double d;
99 } in, out;
100 in.d = C;
101 out.i = llvm::byteswap(in.i);
102 return out.d;
103}
104
105template <typename T>
106inline std::enable_if_t<std::is_enum<T>::value, T> getSwappedBytes(T C) {
107 return static_cast<T>(
108 llvm::byteswap(static_cast<std::underlying_type_t<T>>(C)));
109}
110
111template<typename T>
112inline void swapByteOrder(T &Value) {
114}
115
116} // end namespace sys
117} // end namespace llvm
118
119#endif
Given that RA is a live value
This file implements the C++20 <bit> header.
LLVM Value Representation.
Definition: Value.h:74
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
static const bool IsLittleEndianHost
Definition: SwapByteOrder.h:67
unsigned char getSwappedBytes(unsigned char C)
Definition: SwapByteOrder.h:69
constexpr bool IsBigEndianHost
Definition: SwapByteOrder.h:64
void swapByteOrder(T &Value)
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
uint64_t ByteSwap_64(uint64_t value)
This function returns a byte-swapped representation of the 64-bit argument.
Definition: SwapByteOrder.h:57
constexpr T byteswap(T V) noexcept
Reverses the bytes in the given integer value V.
Definition: bit.h:65
uint32_t ByteSwap_32(uint32_t value)
This function returns a byte-swapped representation of the 32-bit argument.
Definition: SwapByteOrder.h:54
uint16_t ByteSwap_16(uint16_t value)
ByteSwap_16 - This function returns a byte-swapped representation of the 16-bit argument.
Definition: SwapByteOrder.h:51