sim/byteswap.hh

   1 /*
   2  * Copyright (c) 2004 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 //The purpose of this file is to provide endainness conversion utility
  30 //functions. Depending on the endianness of the guest system, either
  31 //the LittleEndianGuest or BigEndianGuest namespace is used.
  32
  33 #ifndef __SIM_BYTE_SWAP_HH__
  34 #define __SIM_BYTE_SWAP_HH__
  35
  36 #include "sim/host.hh"
  37
  38 // This lets us figure out what the byte order of the host system is
  39 #if defined(linux)
  40 #include <endian.h>
  41 #else
  42 #include <machine/endian.h>
  43 #endif
  44
  45 //These functions actually perform the swapping for parameters
  46 //of various bit lengths
  47 static inline uint64_t
  48 swap_byte64(uint64_t x)
  49 {
  50     return  (uint64_t)((((uint64_t)(x) & 0xff) << 56) |
  51             ((uint64_t)(x) & 0xff00ULL) << 40 |
  52             ((uint64_t)(x) & 0xff0000ULL) << 24 |
  53             ((uint64_t)(x) & 0xff000000ULL) << 8 |
  54             ((uint64_t)(x) & 0xff00000000ULL) >> 8 |
  55             ((uint64_t)(x) & 0xff0000000000ULL) >> 24 |
  56             ((uint64_t)(x) & 0xff000000000000ULL) >> 40 |
  57             ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ;
  58 }
  59
  60 static inline uint32_t
  61 swap_byte32(uint32_t x)
  62 {
  63     return  (uint32_t)(((uint32_t)(x) & 0xff) << 24 |
  64             ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 |
  65             ((uint32_t)(x) & 0xff000000) >> 24);
  66
  67 }
  68
  69 static inline uint16_t
  70 swap_byte16(uint16_t x)
  71 {
  72     return (uint16_t)(((uint16_t)(x) & 0xff) << 8 |
  73                       ((uint16_t)(x) & 0xff00) >> 8);
  74 }
  75
  76 //This lets the compiler figure out how to call the swap_byte functions above
  77 //for different data types.
  78 static inline uint64_t swap_byte(uint64_t x) {return swap_byte64(x);}
  79 static inline int64_t swap_byte(int64_t x) {return swap_byte64((uint64_t)x);}
  80 static inline uint32_t swap_byte(uint32_t x) {return swap_byte32(x);}
  81 static inline int32_t swap_byte(int32_t x) {return swap_byte32((uint32_t)x);}
  82 #if defined(__APPLE__)
  83 static inline long swap_byte(long x) {return swap_byte32((long)x);}
  84 static inline unsigned long swap_byte(unsigned long x)
  85                                 { return swap_byte32((unsigned long)x);}
  86 #endif
  87 static inline uint16_t swap_byte(uint16_t x) {return swap_byte32(x);}
  88 static inline int16_t swap_byte(int16_t x) {return swap_byte16((uint16_t)x);}
  89 static inline uint8_t swap_byte(uint8_t x) {return x;}
  90 static inline int8_t swap_byte(int8_t x) {return x;}
  91 static inline double swap_byte(double x) {return swap_byte64((uint64_t)x);}
  92 static inline float swap_byte(float x) {return swap_byte32((uint32_t)x);}
  93
  94 //The conversion functions with fixed endianness on both ends don't need to
  95 //be in a namespace
  96 template <typename T> static inline T betole(T value) {return swap_byte(value);}
  97 template <typename T> static inline T letobe(T value) {return swap_byte(value);}
  98
  99 //For conversions not involving the guest system, we can define the functions
 100 //conditionally based on the BYTE_ORDER macro and outside of the namespaces
 101 #if BYTE_ORDER == BIG_ENDIAN
 102 template <typename T> static inline T htole(T value) {return swap_byte(value);}
 103 template <typename T> static inline T letoh(T value) {return swap_byte(value);}
 104 template <typename T> static inline T htobe(T value) {return value;}
 105 template <typename T> static inline T betoh(T value) {return value;}
 106 #elif BYTE_ORDER == LITTLE_ENDIAN
 107 template <typename T> static inline T htole(T value) {return value;}
 108 template <typename T> static inline T letoh(T value) {return value;}
 109 template <typename T> static inline T htobe(T value) {return swap_byte(value);}
 110 template <typename T> static inline T betoh(T value) {return swap_byte(value);}
 111 #else
 112         #error Invalid Endianess
 113 #endif
 114
 115 namespace BigEndianGuest
 116 {
 117         template <typename T>
 118         static inline T gtole(T value) {return betole(value);}
 119         template <typename T>
 120         static inline T letog(T value) {return letobe(value);}
 121         template <typename T>
 122         static inline T gtobe(T value) {return value;}
 123         template <typename T>
 124         static inline T betog(T value) {return value;}
 125         template <typename T>
 126         static inline T htog(T value) {return htobe(value);}
 127         template <typename T>
 128         static inline T gtoh(T value) {return betoh(value);}
 129 }
 130
 131 namespace LittleEndianGuest
 132 {
 133         template <typename T>
 134         static inline T gtole(T value) {return value;}
 135         template <typename T>
 136         static inline T letog(T value) {return value;}
 137         template <typename T>
 138         static inline T gtobe(T value) {return letobe(value);}
 139         template <typename T>
 140         static inline T betog(T value) {return betole(value);}
 141         template <typename T>
 142         static inline T htog(T value) {return htole(value);}
 143         template <typename T>
 144         static inline T gtoh(T value) {return letoh(value);}
 145 }
 146 #endif // __SIM_BYTE_SWAP_HH__