1 /*- 2 * Copyright (c) 1987, 1991 Regents of the University of California. 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 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)endian.h 7.8 (Berkeley) 4/3/91 30 * $FreeBSD$ 31 */ 32 33 #ifndef _MACHINE_ENDIAN_H_ 34 #define _MACHINE_ENDIAN_H_ 35 36 #include <sys/cdefs.h> 37 #include <sys/_types.h> 38 39 /* 40 * Define the order of 32-bit words in 64-bit words. 41 */ 42 #define _QUAD_HIGHWORD 1 43 #define _QUAD_LOWWORD 0 44 45 /* 46 * Definitions for byte order, according to byte significance from low 47 * address to high. 48 */ 49 #define _LITTLE_ENDIAN 1234 /* LSB first: i386, vax */ 50 #define _BIG_ENDIAN 4321 /* MSB first: 68000, ibm, net */ 51 #define _PDP_ENDIAN 3412 /* LSB first in word, MSW first in long */ 52 53 #define _BYTE_ORDER _LITTLE_ENDIAN 54 55 /* 56 * Deprecated variants that don't have enough underscores to be useful in more 57 * strict namespaces. 58 */ 59 #if __BSD_VISIBLE 60 #define LITTLE_ENDIAN _LITTLE_ENDIAN 61 #define BIG_ENDIAN _BIG_ENDIAN 62 #define PDP_ENDIAN _PDP_ENDIAN 63 #define BYTE_ORDER _BYTE_ORDER 64 #endif 65 66 #define __bswap16_gen(x) (__uint16_t)((x) << 8 | (x) >> 8) 67 #define __bswap32_gen(x) \ 68 (((__uint32_t)__bswap16((x) & 0xffff) << 16) | __bswap16((x) >> 16)) 69 #define __bswap64_gen(x) \ 70 (((__uint64_t)__bswap32((x) & 0xffffffff) << 32) | __bswap32((x) >> 32)) 71 72 #ifdef __GNUCLIKE_BUILTIN_CONSTANT_P 73 #define __bswap16(x) \ 74 ((__uint16_t)(__builtin_constant_p(x) ? \ 75 __bswap16_gen((__uint16_t)(x)) : __bswap16_var(x))) 76 #define __bswap32(x) \ 77 (__builtin_constant_p(x) ? \ 78 __bswap32_gen((__uint32_t)(x)) : __bswap32_var(x)) 79 #define __bswap64(x) \ 80 (__builtin_constant_p(x) ? \ 81 __bswap64_gen((__uint64_t)(x)) : __bswap64_var(x)) 82 #else 83 /* XXX these are broken for use in static initializers. */ 84 #define __bswap16(x) __bswap16_var(x) 85 #define __bswap32(x) __bswap32_var(x) 86 #define __bswap64(x) __bswap64_var(x) 87 #endif 88 89 /* These are defined as functions to avoid multiple evaluation of x. */ 90 91 static __inline __uint16_t 92 __bswap16_var(__uint16_t _x) 93 { 94 95 return (__bswap16_gen(_x)); 96 } 97 98 static __inline __uint32_t 99 __bswap32_var(__uint32_t _x) 100 { 101 102 #ifdef __GNUCLIKE_ASM 103 __asm("bswap %0" : "+r" (_x)); 104 return (_x); 105 #else 106 return (__bswap32_gen(_x)); 107 #endif 108 } 109 110 static __inline __uint64_t 111 __bswap64_var(__uint64_t _x) 112 { 113 114 #if defined(__amd64__) && defined(__GNUCLIKE_ASM) 115 __asm("bswap %0" : "+r" (_x)); 116 return (_x); 117 #else 118 /* 119 * It is important for the optimizations that the following is not 120 * really generic, but expands to 2 __bswap32_var()'s. 121 */ 122 return (__bswap64_gen(_x)); 123 #endif 124 } 125 126 #define __htonl(x) __bswap32(x) 127 #define __htons(x) __bswap16(x) 128 #define __ntohl(x) __bswap32(x) 129 #define __ntohs(x) __bswap16(x) 130 131 #endif /* !_MACHINE_ENDIAN_H_ */ 132