byteswap.hh revision 3799
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: Gabe Black 29 * Ali Saidi 30 * Nathan Binkert 31 */ 32 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. 36 37#ifndef __SIM_BYTE_SWAP_HH__ 38#define __SIM_BYTE_SWAP_HH__ 39 40#include "base/misc.hh" 41#include "sim/host.hh" 42 43// This lets us figure out what the byte order of the host system is 44#if defined(linux) 45#include <endian.h> 46// If this is a linux system, lets used the optimized definitions if they exist. 47// If one doesn't exist, we pretty much get what is listed below, so it all 48// works out 49#include <byteswap.h> 50#elif defined (__sun__) 51#include <sys/isa_defs.h> 52#else 53#include <machine/endian.h> 54#endif 55 56#if defined(__APPLE__) 57#include <libkern/OSByteOrder.h> 58#endif 59 60enum ByteOrder {BigEndianByteOrder, LittleEndianByteOrder}; 61 62//These functions actually perform the swapping for parameters 63//of various bit lengths 64static inline uint64_t 65swap_byte64(uint64_t x) 66{ 67#if defined(linux) 68 return bswap_64(x); 69#elif defined(__APPLE__) 70 return OSSwapInt64(x); 71#else 72 return (uint64_t)((((uint64_t)(x) & 0xff) << 56) | 73 ((uint64_t)(x) & 0xff00ULL) << 40 | 74 ((uint64_t)(x) & 0xff0000ULL) << 24 | 75 ((uint64_t)(x) & 0xff000000ULL) << 8 | 76 ((uint64_t)(x) & 0xff00000000ULL) >> 8 | 77 ((uint64_t)(x) & 0xff0000000000ULL) >> 24 | 78 ((uint64_t)(x) & 0xff000000000000ULL) >> 40 | 79 ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ; 80#endif 81} 82 83static inline uint32_t 84swap_byte32(uint32_t x) 85{ 86#if defined(linux) 87 return bswap_32(x); 88#elif defined(__APPLE__) 89 return OSSwapInt32(x); 90#else 91 return (uint32_t)(((uint32_t)(x) & 0xff) << 24 | 92 ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 | 93 ((uint32_t)(x) & 0xff000000) >> 24); 94#endif 95} 96 97static inline uint16_t 98swap_byte16(uint16_t x) 99{ 100#if defined(linux) 101 return bswap_16(x); 102#elif defined(__APPLE__) 103 return OSSwapInt16(x); 104#else 105 return (uint16_t)(((uint16_t)(x) & 0xff) << 8 | 106 ((uint16_t)(x) & 0xff00) >> 8); 107#endif 108} 109 110// This function lets the compiler figure out how to call the 111// swap_byte functions above for different data types. Since the 112// sizeof() values are known at compiel time, it should inline to a 113// direct call to the right swap_byteNN() function. 114template <typename T> 115static inline T swap_byte(T x) { 116 if (sizeof(T) == 8) 117 return swap_byte64((uint64_t)x); 118 else if (sizeof(T) == 4) 119 return swap_byte32((uint32_t)x); 120 else if (sizeof(T) == 2) 121 return swap_byte16((uint16_t)x); 122 else if (sizeof(T) == 1) 123 return x; 124 else 125 panic("Can't byte-swap values larger than 64 bits"); 126} 127 128//The conversion functions with fixed endianness on both ends don't need to 129//be in a namespace 130template <typename T> static inline T betole(T value) {return swap_byte(value);} 131template <typename T> static inline T letobe(T value) {return swap_byte(value);} 132 133//For conversions not involving the guest system, we can define the functions 134//conditionally based on the BYTE_ORDER macro and outside of the namespaces 135#if defined(_BIG_ENDIAN) || BYTE_ORDER == BIG_ENDIAN 136const ByteOrder HostByteOrder = BigEndianByteOrder; 137template <typename T> static inline T htole(T value) {return swap_byte(value);} 138template <typename T> static inline T letoh(T value) {return swap_byte(value);} 139template <typename T> static inline T htobe(T value) {return value;} 140template <typename T> static inline T betoh(T value) {return value;} 141#elif defined(_LITTLE_ENDIAN) || BYTE_ORDER == LITTLE_ENDIAN 142const ByteOrder HostByteOrder = LittleEndianByteOrder; 143template <typename T> static inline T htole(T value) {return value;} 144template <typename T> static inline T letoh(T value) {return value;} 145template <typename T> static inline T htobe(T value) {return swap_byte(value);} 146template <typename T> static inline T betoh(T value) {return swap_byte(value);} 147#else 148 #error Invalid Endianess 149#endif 150 151namespace BigEndianGuest 152{ 153 const bool ByteOrderDiffers = (HostByteOrder != BigEndianByteOrder); 154 template <typename T> 155 static inline T gtole(T value) {return betole(value);} 156 template <typename T> 157 static inline T letog(T value) {return letobe(value);} 158 template <typename T> 159 static inline T gtobe(T value) {return value;} 160 template <typename T> 161 static inline T betog(T value) {return value;} 162 template <typename T> 163 static inline T htog(T value) {return htobe(value);} 164 template <typename T> 165 static inline T gtoh(T value) {return betoh(value);} 166} 167 168namespace LittleEndianGuest 169{ 170 const bool ByteOrderDiffers = (HostByteOrder != LittleEndianByteOrder); 171 template <typename T> 172 static inline T gtole(T value) {return value;} 173 template <typename T> 174 static inline T letog(T value) {return value;} 175 template <typename T> 176 static inline T gtobe(T value) {return letobe(value);} 177 template <typename T> 178 static inline T betog(T value) {return betole(value);} 179 template <typename T> 180 static inline T htog(T value) {return htole(value);} 181 template <typename T> 182 static inline T gtoh(T value) {return letoh(value);} 183} 184#endif // __SIM_BYTE_SWAP_HH__ 185