byteswap.hh revision 2956
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#else 51#include <machine/endian.h> 52#endif 53 54#if defined(__APPLE__) 55#include <libkern/OSByteOrder.h> 56#endif 57 58//These functions actually perform the swapping for parameters 59//of various bit lengths 60static inline uint64_t 61swap_byte64(uint64_t x) 62{ 63#if defined(linux) 64 return bswap_64(x); 65#elif defined(__APPLE__) 66 return OSSwapInt64(x); 67#else 68 return (uint64_t)((((uint64_t)(x) & 0xff) << 56) | 69 ((uint64_t)(x) & 0xff00ULL) << 40 | 70 ((uint64_t)(x) & 0xff0000ULL) << 24 | 71 ((uint64_t)(x) & 0xff000000ULL) << 8 | 72 ((uint64_t)(x) & 0xff00000000ULL) >> 8 | 73 ((uint64_t)(x) & 0xff0000000000ULL) >> 24 | 74 ((uint64_t)(x) & 0xff000000000000ULL) >> 40 | 75 ((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ; 76#endif 77} 78 79static inline uint32_t 80swap_byte32(uint32_t x) 81{ 82#if defined(linux) 83 return bswap_32(x); 84#elif defined(__APPLE__) 85 return OSSwapInt32(x); 86#else 87 return (uint32_t)(((uint32_t)(x) & 0xff) << 24 | 88 ((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 | 89 ((uint32_t)(x) & 0xff000000) >> 24); 90#endif 91} 92 93static inline uint16_t 94swap_byte16(uint16_t x) 95{ 96#if defined(linux) 97 return bswap_16(x); 98#elif defined(__APPLE__) 99 return OSSwapInt16(x); 100#else 101 return (uint16_t)(((uint16_t)(x) & 0xff) << 8 | 102 ((uint16_t)(x) & 0xff00) >> 8); 103#endif 104} 105 106// This function lets the compiler figure out how to call the 107// swap_byte functions above for different data types. Since the 108// sizeof() values are known at compiel time, it should inline to a 109// direct call to the right swap_byteNN() function. 110template <typename T> 111static inline T swap_byte(T x) { 112 if (sizeof(T) == 8) 113 return swap_byte64((uint64_t)x); 114 else if (sizeof(T) == 4) 115 return swap_byte32((uint32_t)x); 116 else if (sizeof(T) == 2) 117 return swap_byte16((uint16_t)x); 118 else if (sizeof(T) == 1) 119 return x; 120 else 121 panic("Can't byte-swap values larger than 64 bits"); 122} 123 124//The conversion functions with fixed endianness on both ends don't need to 125//be in a namespace 126template <typename T> static inline T betole(T value) {return swap_byte(value);} 127template <typename T> static inline T letobe(T value) {return swap_byte(value);} 128 129//For conversions not involving the guest system, we can define the functions 130//conditionally based on the BYTE_ORDER macro and outside of the namespaces 131#if BYTE_ORDER == BIG_ENDIAN 132template <typename T> static inline T htole(T value) {return swap_byte(value);} 133template <typename T> static inline T letoh(T value) {return swap_byte(value);} 134template <typename T> static inline T htobe(T value) {return value;} 135template <typename T> static inline T betoh(T value) {return value;} 136#elif BYTE_ORDER == LITTLE_ENDIAN 137template <typename T> static inline T htole(T value) {return value;} 138template <typename T> static inline T letoh(T value) {return value;} 139template <typename T> static inline T htobe(T value) {return swap_byte(value);} 140template <typename T> static inline T betoh(T value) {return swap_byte(value);} 141#else 142 #error Invalid Endianess 143#endif 144 145namespace BigEndianGuest 146{ 147 template <typename T> 148 static inline T gtole(T value) {return betole(value);} 149 template <typename T> 150 static inline T letog(T value) {return letobe(value);} 151 template <typename T> 152 static inline T gtobe(T value) {return value;} 153 template <typename T> 154 static inline T betog(T value) {return value;} 155 template <typename T> 156 static inline T htog(T value) {return htobe(value);} 157 template <typename T> 158 static inline T gtoh(T value) {return betoh(value);} 159} 160 161namespace LittleEndianGuest 162{ 163 template <typename T> 164 static inline T gtole(T value) {return value;} 165 template <typename T> 166 static inline T letog(T value) {return value;} 167 template <typename T> 168 static inline T gtobe(T value) {return letobe(value);} 169 template <typename T> 170 static inline T betog(T value) {return betole(value);} 171 template <typename T> 172 static inline T htog(T value) {return htole(value);} 173 template <typename T> 174 static inline T gtoh(T value) {return letoh(value);} 175} 176#endif // __SIM_BYTE_SWAP_HH__ 177