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33 //The purpose of this file is to provide endainness conversion utility
34 //functions. Depending on the endianness of the guest system, either
35 //the LittleEndianGuest or BigEndianGuest namespace is used.
37 #ifndef __SIM_BYTE_SWAP_HH__
38 #define __SIM_BYTE_SWAP_HH__
40 #include "base/bigint.hh"
41 #include "base/misc.hh"
42 #include "base/types.hh"
44 // This lets us figure out what the byte order of the host system is
45 #if defined(__linux__)
47 // If this is a linux system, lets used the optimized definitions if they exist.
48 // If one doesn't exist, we pretty much get what is listed below, so it all
52 #include <sys/isa_defs.h>
54 #include <machine/endian.h>
57 #if defined(__APPLE__)
58 #include <libkern/OSByteOrder.h>
61 //These functions actually perform the swapping for parameters
62 //of various bit lengths
64 swap_byte64(uint64_t x)
66 #if defined(__linux__)
68 #elif defined(__APPLE__)
69 return OSSwapInt64(x);
71 return (uint64_t)((((uint64_t)(x) & 0xff) << 56) |
72 ((uint64_t)(x) & 0xff00ULL) << 40 |
73 ((uint64_t)(x) & 0xff0000ULL) << 24 |
74 ((uint64_t)(x) & 0xff000000ULL) << 8 |
75 ((uint64_t)(x) & 0xff00000000ULL) >> 8 |
76 ((uint64_t)(x) & 0xff0000000000ULL) >> 24 |
77 ((uint64_t)(x) & 0xff000000000000ULL) >> 40 |
78 ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ;
83 swap_byte32(uint32_t x)
85 #if defined(__linux__)
87 #elif defined(__APPLE__)
88 return OSSwapInt32(x);
90 return (uint32_t)(((uint32_t)(x) & 0xff) << 24 |
91 ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 |
92 ((uint32_t)(x) & 0xff000000) >> 24);
97 swap_byte16(uint16_t x)
99 #if defined(__linux__)
101 #elif defined(__APPLE__)
102 return OSSwapInt16(x);
104 return (uint16_t)(((uint16_t)(x) & 0xff) << 8 |
105 ((uint16_t)(x) & 0xff00) >> 8);
109 // This function lets the compiler figure out how to call the
110 // swap_byte functions above for different data types. Since the
111 // sizeof() values are known at compile time, it should inline to a
112 // direct call to the right swap_byteNN() function.
113 template <typename T>
114 inline T swap_byte(T x) {
116 return swap_byte64((uint64_t)x);
117 else if (sizeof(T) == 4)
118 return swap_byte32((uint32_t)x);
119 else if (sizeof(T) == 2)
120 return swap_byte16((uint16_t)x);
121 else if (sizeof(T) == 1)
124 panic("Can't byte-swap values larger than 64 bits");
128 inline Twin64_t swap_byte<Twin64_t>(Twin64_t x)
130 x.a = swap_byte(x.a);
131 x.b = swap_byte(x.b);
136 inline Twin32_t swap_byte<Twin32_t>(Twin32_t x)
138 x.a = swap_byte(x.a);
139 x.b = swap_byte(x.b);
143 //The conversion functions with fixed endianness on both ends don't need to
145 template <typename T> inline T betole(T value) {return swap_byte(value);}
146 template <typename T> inline T letobe(T value) {return swap_byte(value);}
148 //For conversions not involving the guest system, we can define the functions
149 //conditionally based on the BYTE_ORDER macro and outside of the namespaces
150 #if (defined(_BIG_ENDIAN) || !defined(_LITTLE_ENDIAN)) && BYTE_ORDER == BIG_ENDIAN
151 const ByteOrder HostByteOrder = BigEndianByteOrder;
152 template <typename T> inline T htole(T value) {return swap_byte(value);}
153 template <typename T> inline T letoh(T value) {return swap_byte(value);}
154 template <typename T> inline T htobe(T value) {return value;}
155 template <typename T> inline T betoh(T value) {return value;}
156 #elif defined(_LITTLE_ENDIAN) || BYTE_ORDER == LITTLE_ENDIAN
157 const ByteOrder HostByteOrder = LittleEndianByteOrder;
158 template <typename T> inline T htole(T value) {return value;}
159 template <typename T> inline T letoh(T value) {return value;}
160 template <typename T> inline T htobe(T value) {return swap_byte(value);}
161 template <typename T> inline T betoh(T value) {return swap_byte(value);}
163 #error Invalid Endianess
166 namespace BigEndianGuest
168 const ByteOrder GuestByteOrder = BigEndianByteOrder;
169 template <typename T>
170 inline T gtole(T value) {return betole(value);}
171 template <typename T>
172 inline T letog(T value) {return letobe(value);}
173 template <typename T>
174 inline T gtobe(T value) {return value;}
175 template <typename T>
176 inline T betog(T value) {return value;}
177 template <typename T>
178 inline T htog(T value) {return htobe(value);}
179 template <typename T>
180 inline T gtoh(T value) {return betoh(value);}
183 namespace LittleEndianGuest
185 const ByteOrder GuestByteOrder = LittleEndianByteOrder;
186 template <typename T>
187 inline T gtole(T value) {return value;}
188 template <typename T>
189 inline T letog(T value) {return value;}
190 template <typename T>
191 inline T gtobe(T value) {return letobe(value);}
192 template <typename T>
193 inline T betog(T value) {return betole(value);}
194 template <typename T>
195 inline T htog(T value) {return htole(value);}
196 template <typename T>
197 inline T gtoh(T value) {return letoh(value);}
199 #endif // __SIM_BYTE_SWAP_HH__