summaryrefslogtreecommitdiff
path: root/src/sim/byteswap.hh
blob: a8c5da9d7661f679a8a7a2455abb82a138d636a1 (plain)
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
/*
 * Copyright (c) 2004 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

//The purpose of this file is to provide endainness conversion utility
//functions. Depending on the endianness of the guest system, either
//the LittleEndianGuest or BigEndianGuest namespace is used.

#ifndef __SIM_BYTE_SWAP_HH__
#define __SIM_BYTE_SWAP_HH__

#include "sim/host.hh"

// This lets us figure out what the byte order of the host system is
#if defined(linux)
#include <endian.h>
// If this is a linux system, lets used the optimized definitions if they exist.
// If one doesn't exist, we pretty much get what is listed below, so it all
// works out
#include <byteswap.h>
#else
#include <machine/endian.h>
#endif

//These functions actually perform the swapping for parameters
//of various bit lengths
static inline uint64_t
swap_byte64(uint64_t x)
{
#if defined(linux)
    return bswap_64(x);
#else
    return  (uint64_t)((((uint64_t)(x) & 0xff) << 56) |
            ((uint64_t)(x) & 0xff00ULL) << 40 |
            ((uint64_t)(x) & 0xff0000ULL) << 24 |
            ((uint64_t)(x) & 0xff000000ULL) << 8 |
            ((uint64_t)(x) & 0xff00000000ULL) >> 8 |
            ((uint64_t)(x) & 0xff0000000000ULL) >> 24 |
            ((uint64_t)(x) & 0xff000000000000ULL) >> 40 |
            ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ;
#endif
}

static inline uint32_t
swap_byte32(uint32_t x)
{
#if defined(linux)
    return bswap_32(x);
#else
    return  (uint32_t)(((uint32_t)(x) & 0xff) << 24 |
            ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 |
            ((uint32_t)(x) & 0xff000000) >> 24);
#endif
}

static inline uint16_t
swap_byte16(uint16_t x)
{
#if defined(linux)
    return bswap_16(x);
#else
    return (uint16_t)(((uint16_t)(x) & 0xff) << 8 |
                      ((uint16_t)(x) & 0xff00) >> 8);
#endif
}

//This lets the compiler figure out how to call the swap_byte functions above
//for different data types.
static inline uint64_t swap_byte(uint64_t x) {return swap_byte64(x);}
static inline int64_t swap_byte(int64_t x) {return swap_byte64((uint64_t)x);}
static inline uint32_t swap_byte(uint32_t x) {return swap_byte32(x);}
static inline int32_t swap_byte(int32_t x) {return swap_byte32((uint32_t)x);}
//This is to prevent the following two functions from compiling on
//64bit machines. It won't detect everything, so it should be changed.
#ifndef __x86_64__
static inline long swap_byte(long x) {return swap_byte32((long)x);}
static inline unsigned long swap_byte(unsigned long x)
                                { return swap_byte32((unsigned long)x);}
#endif
static inline uint16_t swap_byte(uint16_t x) {return swap_byte32(x);}
static inline int16_t swap_byte(int16_t x) {return swap_byte16((uint16_t)x);}
static inline uint8_t swap_byte(uint8_t x) {return x;}
static inline int8_t swap_byte(int8_t x) {return x;}
static inline double swap_byte(double x) {return swap_byte64((uint64_t)x);}
static inline float swap_byte(float x) {return swap_byte32((uint32_t)x);}

//The conversion functions with fixed endianness on both ends don't need to
//be in a namespace
template <typename T> static inline T betole(T value) {return swap_byte(value);}
template <typename T> static inline T letobe(T value) {return swap_byte(value);}

//For conversions not involving the guest system, we can define the functions
//conditionally based on the BYTE_ORDER macro and outside of the namespaces
#if BYTE_ORDER == BIG_ENDIAN
template <typename T> static inline T htole(T value) {return swap_byte(value);}
template <typename T> static inline T letoh(T value) {return swap_byte(value);}
template <typename T> static inline T htobe(T value) {return value;}
template <typename T> static inline T betoh(T value) {return value;}
#elif BYTE_ORDER == LITTLE_ENDIAN
template <typename T> static inline T htole(T value) {return value;}
template <typename T> static inline T letoh(T value) {return value;}
template <typename T> static inline T htobe(T value) {return swap_byte(value);}
template <typename T> static inline T betoh(T value) {return swap_byte(value);}
#else
        #error Invalid Endianess
#endif

namespace BigEndianGuest
{
        template <typename T>
        static inline T gtole(T value) {return betole(value);}
        template <typename T>
        static inline T letog(T value) {return letobe(value);}
        template <typename T>
        static inline T gtobe(T value) {return value;}
        template <typename T>
        static inline T betog(T value) {return value;}
        template <typename T>
        static inline T htog(T value) {return htobe(value);}
        template <typename T>
        static inline T gtoh(T value) {return betoh(value);}
}

namespace LittleEndianGuest
{
        template <typename T>
        static inline T gtole(T value) {return value;}
        template <typename T>
        static inline T letog(T value) {return value;}
        template <typename T>
        static inline T gtobe(T value) {return letobe(value);}
        template <typename T>
        static inline T betog(T value) {return betole(value);}
        template <typename T>
        static inline T htog(T value) {return htole(value);}
        template <typename T>
        static inline T gtoh(T value) {return letoh(value);}
}
#endif // __SIM_BYTE_SWAP_HH__