byteswap.hh revision 2779
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 "base/misc.hh" 40#include "sim/host.hh" 41 42// This lets us figure out what the byte order of the host system is 43#if defined(linux) 44#include <endian.h> 45// If this is a linux system, lets used the optimized definitions if they exist. 46// If one doesn't exist, we pretty much get what is listed below, so it all 47// works out 48#include <byteswap.h> 49#else 50#include <machine/endian.h> 51#endif 52 53#if defined(__APPLE__) 54#include <libkern/OSByteOrder.h> 55#endif 56 57//These functions actually perform the swapping for parameters 58//of various bit lengths 59static inline uint64_t 60swap_byte64(uint64_t x) 61{ 62#if defined(linux) 63 return bswap_64(x); 64#elif defined(__APPLE__) 65 return OSSwapInt64(x); 66#else 67 return (uint64_t)((((uint64_t)(x) & 0xff) << 56) | 68 ((uint64_t)(x) & 0xff00ULL) << 40 | 69 ((uint64_t)(x) & 0xff0000ULL) << 24 | 70 ((uint64_t)(x) & 0xff000000ULL) << 8 | 71 ((uint64_t)(x) & 0xff00000000ULL) >> 8 | 72 ((uint64_t)(x) & 0xff0000000000ULL) >> 24 | 73 ((uint64_t)(x) & 0xff000000000000ULL) >> 40 | 74 ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ; 75#endif 76} 77 78static inline uint32_t 79swap_byte32(uint32_t x) 80{ 81#if defined(linux) 82 return bswap_32(x); 83#elif defined(__APPLE__) 84 return OSSwapInt32(x); 85#else 86 return (uint32_t)(((uint32_t)(x) & 0xff) << 24 | 87 ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 | 88 ((uint32_t)(x) & 0xff000000) >> 24); 89#endif 90} 91 92static inline uint16_t 93swap_byte16(uint16_t x) 94{ 95#if defined(linux) 96 return bswap_16(x); 97#elif defined(__APPLE__) 98 return OSSwapInt16(x); 99#else 100 return (uint16_t)(((uint16_t)(x) & 0xff) << 8 | 101 ((uint16_t)(x) & 0xff00) >> 8); 102#endif 103} 104 105// This function lets the compiler figure out how to call the 106// swap_byte functions above for different data types. Since the 107// sizeof() values are known at compiel time, it should inline to a 108// direct call to the right swap_byteNN() function. 109template <typename T> 110static inline T swap_byte(T x) { 111 if (sizeof(T) == 8) 112 return swap_byte64((uint64_t)x); 113 else if (sizeof(T) == 4) 114 return swap_byte32((uint32_t)x); 115 else if (sizeof(T) == 2) 116 return swap_byte16((uint16_t)x); 117 else if (sizeof(T) == 1) 118 return x; 119 else 120 panic("Can't byte-swap values larger than 64 bits"); 121} 122 123//The conversion functions with fixed endianness on both ends don't need to 124//be in a namespace 125template <typename T> static inline T betole(T value) {return swap_byte(value);} 126template <typename T> static inline T letobe(T value) {return swap_byte(value);} 127 128//For conversions not involving the guest system, we can define the functions 129//conditionally based on the BYTE_ORDER macro and outside of the namespaces 130#if BYTE_ORDER == BIG_ENDIAN 131template <typename T> static inline T htole(T value) {return swap_byte(value);} 132template <typename T> static inline T letoh(T value) {return swap_byte(value);} 133template <typename T> static inline T htobe(T value) {return value;} 134template <typename T> static inline T betoh(T value) {return value;} 135#elif BYTE_ORDER == LITTLE_ENDIAN 136template <typename T> static inline T htole(T value) {return value;} 137template <typename T> static inline T letoh(T value) {return value;} 138template <typename T> static inline T htobe(T value) {return swap_byte(value);} 139template <typename T> static inline T betoh(T value) {return swap_byte(value);} 140#else 141 #error Invalid Endianess 142#endif 143 144namespace BigEndianGuest 145{ 146 template <typename T> 147 static inline T gtole(T value) {return betole(value);} 148 template <typename T> 149 static inline T letog(T value) {return letobe(value);} 150 template <typename T> 151 static inline T gtobe(T value) {return value;} 152 template <typename T> 153 static inline T betog(T value) {return value;} 154 template <typename T> 155 static inline T htog(T value) {return htobe(value);} 156 template <typename T> 157 static inline T gtoh(T value) {return betoh(value);} 158} 159 160namespace LittleEndianGuest 161{ 162 template <typename T> 163 static inline T gtole(T value) {return value;} 164 template <typename T> 165 static inline T letog(T value) {return value;} 166 template <typename T> 167 static inline T gtobe(T value) {return letobe(value);} 168 template <typename T> 169 static inline T betog(T value) {return betole(value);} 170 template <typename T> 171 static inline T htog(T value) {return htole(value);} 172 template <typename T> 173 static inline T gtoh(T value) {return letoh(value);} 174} 175#endif // __SIM_BYTE_SWAP_HH__ 176