byteswap.hh revision 12383
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/bigint.hh" 41#include "base/types.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 60//These functions actually perform the swapping for parameters 61//of various bit lengths 62inline uint64_t 63swap_byte64(uint64_t x) 64{ 65#if defined(__linux__) 66 return bswap_64(x); 67#elif defined(__APPLE__) 68 return OSSwapInt64(x); 69#else 70 return (uint64_t)((((uint64_t)(x) & 0xff) << 56) | 71 ((uint64_t)(x) & 0xff00ULL) << 40 | 72 ((uint64_t)(x) & 0xff0000ULL) << 24 | 73 ((uint64_t)(x) & 0xff000000ULL) << 8 | 74 ((uint64_t)(x) & 0xff00000000ULL) >> 8 | 75 ((uint64_t)(x) & 0xff0000000000ULL) >> 24 | 76 ((uint64_t)(x) & 0xff000000000000ULL) >> 40 | 77 ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ; 78#endif 79} 80 81inline uint32_t 82swap_byte32(uint32_t x) 83{ 84#if defined(__linux__) 85 return bswap_32(x); 86#elif defined(__APPLE__) 87 return OSSwapInt32(x); 88#else 89 return (uint32_t)(((uint32_t)(x) & 0xff) << 24 | 90 ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 | 91 ((uint32_t)(x) & 0xff000000) >> 24); 92#endif 93} 94 95inline uint16_t 96swap_byte16(uint16_t x) 97{ 98#if defined(__linux__) 99 return bswap_16(x); 100#elif defined(__APPLE__) 101 return OSSwapInt16(x); 102#else 103 return (uint16_t)(((uint16_t)(x) & 0xff) << 8 | 104 ((uint16_t)(x) & 0xff00) >> 8); 105#endif 106} 107 108// This function lets the compiler figure out how to call the 109// swap_byte functions above for different data types. Since the 110// sizeof() values are known at compile time, it should inline to a 111// direct call to the right swap_byteNN() function. 112template <typename T> 113inline T swap_byte(T x) { 114 if (sizeof(T) == 8) 115 return swap_byte64((uint64_t)x); 116 else if (sizeof(T) == 4) 117 return swap_byte32((uint32_t)x); 118 else if (sizeof(T) == 2) 119 return swap_byte16((uint16_t)x); 120 else if (sizeof(T) == 1) 121 return x; 122 else 123 panic("Can't byte-swap values larger than 64 bits"); 124} 125 126template<> 127inline Twin64_t swap_byte<Twin64_t>(Twin64_t x) 128{ 129 x.a = swap_byte(x.a); 130 x.b = swap_byte(x.b); 131 return x; 132} 133 134template<> 135inline Twin32_t swap_byte<Twin32_t>(Twin32_t x) 136{ 137 x.a = swap_byte(x.a); 138 x.b = swap_byte(x.b); 139 return x; 140} 141 142template <typename T, size_t N> 143inline std::array<T, N> 144swap_byte(std::array<T, N> a) 145{ 146 for (T &v: a) 147 v = swap_byte(v); 148 return a; 149} 150 151//The conversion functions with fixed endianness on both ends don't need to 152//be in a namespace 153template <typename T> inline T betole(T value) {return swap_byte(value);} 154template <typename T> inline T letobe(T value) {return swap_byte(value);} 155 156//For conversions not involving the guest system, we can define the functions 157//conditionally based on the BYTE_ORDER macro and outside of the namespaces 158#if (defined(_BIG_ENDIAN) || !defined(_LITTLE_ENDIAN)) && BYTE_ORDER == BIG_ENDIAN 159const ByteOrder HostByteOrder = BigEndianByteOrder; 160template <typename T> inline T htole(T value) {return swap_byte(value);} 161template <typename T> inline T letoh(T value) {return swap_byte(value);} 162template <typename T> inline T htobe(T value) {return value;} 163template <typename T> inline T betoh(T value) {return value;} 164#elif defined(_LITTLE_ENDIAN) || BYTE_ORDER == LITTLE_ENDIAN 165const ByteOrder HostByteOrder = LittleEndianByteOrder; 166template <typename T> inline T htole(T value) {return value;} 167template <typename T> inline T letoh(T value) {return value;} 168template <typename T> inline T htobe(T value) {return swap_byte(value);} 169template <typename T> inline T betoh(T value) {return swap_byte(value);} 170#else 171 #error Invalid Endianess 172#endif 173 174namespace BigEndianGuest 175{ 176 const ByteOrder GuestByteOrder = BigEndianByteOrder; 177 template <typename T> 178 inline T gtole(T value) {return betole(value);} 179 template <typename T> 180 inline T letog(T value) {return letobe(value);} 181 template <typename T> 182 inline T gtobe(T value) {return value;} 183 template <typename T> 184 inline T betog(T value) {return value;} 185 template <typename T> 186 inline T htog(T value) {return htobe(value);} 187 template <typename T> 188 inline T gtoh(T value) {return betoh(value);} 189} 190 191namespace LittleEndianGuest 192{ 193 const ByteOrder GuestByteOrder = LittleEndianByteOrder; 194 template <typename T> 195 inline T gtole(T value) {return value;} 196 template <typename T> 197 inline T letog(T value) {return value;} 198 template <typename T> 199 inline T gtobe(T value) {return letobe(value);} 200 template <typename T> 201 inline T betog(T value) {return betole(value);} 202 template <typename T> 203 inline T htog(T value) {return htole(value);} 204 template <typename T> 205 inline T gtoh(T value) {return letoh(value);} 206} 207#endif // __SIM_BYTE_SWAP_HH__ 208