byteswap.hh revision 2778
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 * Authors: Ali Saidi 29 * Nathan Binkert 30 */ 31 32//The purpose of this file is to provide endainness conversion utility 33//functions. Depending on the endianness of the guest system, either 34//the LittleEndianGuest or BigEndianGuest namespace is used. 35 36#ifndef __SIM_BYTE_SWAP_HH__ 37#define __SIM_BYTE_SWAP_HH__ 38 39#include "sim/host.hh" 40 41// This lets us figure out what the byte order of the host system is 42#if defined(linux) 43#include <endian.h> 44// If this is a linux system, lets used the optimized definitions if they exist. 45// If one doesn't exist, we pretty much get what is listed below, so it all 46// works out 47#include <byteswap.h> 48#else 49#include <machine/endian.h> 50#endif 51 52#if defined(__APPLE__) 53#include <libkern/OSByteOrder.h> 54#endif 55 56//These functions actually perform the swapping for parameters 57//of various bit lengths 58static inline uint64_t 59swap_byte64(uint64_t x) 60{ 61#if defined(linux) 62 return bswap_64(x); 63#elif defined(__APPLE__) 64 return OSSwapInt64(x); 65#else 66 return (uint64_t)((((uint64_t)(x) & 0xff) << 56) | 67 ((uint64_t)(x) & 0xff00ULL) << 40 | 68 ((uint64_t)(x) & 0xff0000ULL) << 24 | 69 ((uint64_t)(x) & 0xff000000ULL) << 8 | 70 ((uint64_t)(x) & 0xff00000000ULL) >> 8 | 71 ((uint64_t)(x) & 0xff0000000000ULL) >> 24 | 72 ((uint64_t)(x) & 0xff000000000000ULL) >> 40 | 73 ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ; 74#endif 75} 76 77static inline uint32_t 78swap_byte32(uint32_t x) 79{ 80#if defined(linux) 81 return bswap_32(x); 82#elif defined(__APPLE__) 83 return OSSwapInt32(x); 84#else 85 return (uint32_t)(((uint32_t)(x) & 0xff) << 24 | 86 ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 | 87 ((uint32_t)(x) & 0xff000000) >> 24); 88#endif 89} 90 91static inline uint16_t 92swap_byte16(uint16_t x) 93{ 94#if defined(linux) 95 return bswap_16(x); 96#elif defined(__APPLE__) 97 return OSSwapInt16(x); 98#else 99 return (uint16_t)(((uint16_t)(x) & 0xff) << 8 | 100 ((uint16_t)(x) & 0xff00) >> 8); 101#endif 102} 103 104// This function lets the compiler figure out how to call the 105// swap_byte functions above for different data types. Since the 106// sizeof() values are known at compiel time, it should inline to a 107// direct call to the right swap_byteNN() function. 108template <typename T> 109static inline T swap_byte(T x) { 110 if (sizeof(T) == 8) 111 return swap_byte64((uint64_t)x); 112 else if (sizeof(T) == 4) 113 return swap_byte32((uint32_t)x); 114 else if (sizeof(T) == 2) 115 return swap_byte16((uint16_t)x); 116 else if (sizeof(T) == 1) 117 return x; 118 else 119 panic("Can't byte-swap values larger than 64 bits"); 120} 121 122//The conversion functions with fixed endianness on both ends don't need to 123//be in a namespace 124template <typename T> static inline T betole(T value) {return swap_byte(value);} 125template <typename T> static inline T letobe(T value) {return swap_byte(value);} 126 127//For conversions not involving the guest system, we can define the functions 128//conditionally based on the BYTE_ORDER macro and outside of the namespaces 129#if BYTE_ORDER == BIG_ENDIAN 130template <typename T> static inline T htole(T value) {return swap_byte(value);} 131template <typename T> static inline T letoh(T value) {return swap_byte(value);} 132template <typename T> static inline T htobe(T value) {return value;} 133template <typename T> static inline T betoh(T value) {return value;} 134#elif BYTE_ORDER == LITTLE_ENDIAN 135template <typename T> static inline T htole(T value) {return value;} 136template <typename T> static inline T letoh(T value) {return value;} 137template <typename T> static inline T htobe(T value) {return swap_byte(value);} 138template <typename T> static inline T betoh(T value) {return swap_byte(value);} 139#else 140 #error Invalid Endianess 141#endif 142 143namespace BigEndianGuest 144{ 145 template <typename T> 146 static inline T gtole(T value) {return betole(value);} 147 template <typename T> 148 static inline T letog(T value) {return letobe(value);} 149 template <typename T> 150 static inline T gtobe(T value) {return value;} 151 template <typename T> 152 static inline T betog(T value) {return value;} 153 template <typename T> 154 static inline T htog(T value) {return htobe(value);} 155 template <typename T> 156 static inline T gtoh(T value) {return betoh(value);} 157} 158 159namespace LittleEndianGuest 160{ 161 template <typename T> 162 static inline T gtole(T value) {return value;} 163 template <typename T> 164 static inline T letog(T value) {return value;} 165 template <typename T> 166 static inline T gtobe(T value) {return letobe(value);} 167 template <typename T> 168 static inline T betog(T value) {return betole(value);} 169 template <typename T> 170 static inline T htog(T value) {return htole(value);} 171 template <typename T> 172 static inline T gtoh(T value) {return letoh(value);} 173} 174#endif // __SIM_BYTE_SWAP_HH__ 175