summaryrefslogtreecommitdiff
path: root/src/sim/byteswap.hh
blob: 2c3517f2496c4e88e7ee103bd5b1b9c52e4fa423 (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
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
/*
 * 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.
 *
 * Authors: Gabe Black
 *          Ali Saidi
 *          Nathan Binkert
 */

//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 "base/types.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>
#elif defined (__sun)
#include <sys/isa_defs.h>
#else
#include <machine/endian.h>
#endif

#if defined(__APPLE__)
#include <libkern/OSByteOrder.h>
#endif

//These functions actually perform the swapping for parameters
//of various bit lengths
inline uint64_t
swap_byte64(uint64_t x)
{
#if defined(__linux__)
    return bswap_64(x);
#elif defined(__APPLE__)
    return OSSwapInt64(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
}

inline uint32_t
swap_byte32(uint32_t x)
{
#if defined(__linux__)
    return bswap_32(x);
#elif defined(__APPLE__)
    return OSSwapInt32(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
}

inline uint16_t
swap_byte16(uint16_t x)
{
#if defined(__linux__)
    return bswap_16(x);
#elif defined(__APPLE__)
    return OSSwapInt16(x);
#else
    return (uint16_t)(((uint16_t)(x) & 0xff) << 8 |
                      ((uint16_t)(x) & 0xff00) >> 8);
#endif
}

// This function lets the compiler figure out how to call the
// swap_byte functions above for different data types.  Since the
// sizeof() values are known at compile time, it should inline to a
// direct call to the right swap_byteNN() function.
template <typename T>
inline T swap_byte(T x) {
    if (sizeof(T) == 8)
        return swap_byte64((uint64_t)x);
    else if (sizeof(T) == 4)
        return swap_byte32((uint32_t)x);
    else if (sizeof(T) == 2)
        return swap_byte16((uint16_t)x);
    else if (sizeof(T) == 1)
        return x;
    else
        panic("Can't byte-swap values larger than 64 bits");
}

template <typename T, size_t N>
inline std::array<T, N>
swap_byte(std::array<T, N> a)
{
    for (T &v: a)
        v = swap_byte(v);
    return a;
}

//The conversion functions with fixed endianness on both ends don't need to
//be in a namespace
template <typename T> inline T betole(T value) {return swap_byte(value);}
template <typename T> 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 (defined(_BIG_ENDIAN) || !defined(_LITTLE_ENDIAN)) && BYTE_ORDER == BIG_ENDIAN
const ByteOrder HostByteOrder = BigEndianByteOrder;
template <typename T> inline T htole(T value) {return swap_byte(value);}
template <typename T> inline T letoh(T value) {return swap_byte(value);}
template <typename T> inline T htobe(T value) {return value;}
template <typename T> inline T betoh(T value) {return value;}
#elif defined(_LITTLE_ENDIAN) || BYTE_ORDER == LITTLE_ENDIAN
const ByteOrder HostByteOrder = LittleEndianByteOrder;
template <typename T> inline T htole(T value) {return value;}
template <typename T> inline T letoh(T value) {return value;}
template <typename T> inline T htobe(T value) {return swap_byte(value);}
template <typename T> inline T betoh(T value) {return swap_byte(value);}
#else
        #error Invalid Endianess
#endif

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

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