1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1987, 1991 Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)endian.h 7.8 (Berkeley) 4/3/91 32 * $FreeBSD$ 33 */ 34 35 #ifndef _MACHINE_ENDIAN_H_ 36 #define _MACHINE_ENDIAN_H_ 37 38 #include <sys/cdefs.h> 39 #include <sys/_types.h> 40 41 /* 42 * Define the order of 32-bit words in 64-bit words. 43 */ 44 #define _QUAD_HIGHWORD 1 45 #define _QUAD_LOWWORD 0 46 47 /* 48 * Definitions for byte order, according to byte significance from low 49 * address to high. 50 */ 51 #define _LITTLE_ENDIAN 1234 /* LSB first: i386, vax */ 52 #define _BIG_ENDIAN 4321 /* MSB first: 68000, ibm, net */ 53 #define _PDP_ENDIAN 3412 /* LSB first in word, MSW first in long */ 54 55 #define _BYTE_ORDER _LITTLE_ENDIAN 56 57 /* 58 * Deprecated variants that don't have enough underscores to be useful in more 59 * strict namespaces. 60 */ 61 #if __BSD_VISIBLE 62 #define LITTLE_ENDIAN _LITTLE_ENDIAN 63 #define BIG_ENDIAN _BIG_ENDIAN 64 #define PDP_ENDIAN _PDP_ENDIAN 65 #define BYTE_ORDER _BYTE_ORDER 66 #endif 67 68 #define __bswap16_gen(x) (__uint16_t)((x) << 8 | (x) >> 8) 69 #define __bswap32_gen(x) \ 70 (((__uint32_t)__bswap16((x) & 0xffff) << 16) | __bswap16((x) >> 16)) 71 #define __bswap64_gen(x) \ 72 (((__uint64_t)__bswap32((x) & 0xffffffff) << 32) | __bswap32((x) >> 32)) 73 74 #ifdef __GNUCLIKE_BUILTIN_CONSTANT_P 75 #define __bswap16(x) \ 76 ((__uint16_t)(__builtin_constant_p(x) ? \ 77 __bswap16_gen((__uint16_t)(x)) : __bswap16_var(x))) 78 #define __bswap32(x) \ 79 (__builtin_constant_p(x) ? \ 80 __bswap32_gen((__uint32_t)(x)) : __bswap32_var(x)) 81 #define __bswap64(x) \ 82 (__builtin_constant_p(x) ? \ 83 __bswap64_gen((__uint64_t)(x)) : __bswap64_var(x)) 84 #else 85 /* XXX these are broken for use in static initializers. */ 86 #define __bswap16(x) __bswap16_var(x) 87 #define __bswap32(x) __bswap32_var(x) 88 #define __bswap64(x) __bswap64_var(x) 89 #endif 90 91 /* These are defined as functions to avoid multiple evaluation of x. */ 92 93 static __inline __uint16_t 94 __bswap16_var(__uint16_t _x) 95 { 96 97 return (__bswap16_gen(_x)); 98 } 99 100 static __inline __uint32_t 101 __bswap32_var(__uint32_t _x) 102 { 103 104 #ifdef __GNUCLIKE_ASM 105 __asm("bswap %0" : "+r" (_x)); 106 return (_x); 107 #else 108 return (__bswap32_gen(_x)); 109 #endif 110 } 111 112 static __inline __uint64_t 113 __bswap64_var(__uint64_t _x) 114 { 115 116 #if defined(__amd64__) && defined(__GNUCLIKE_ASM) 117 __asm("bswap %0" : "+r" (_x)); 118 return (_x); 119 #else 120 /* 121 * It is important for the optimizations that the following is not 122 * really generic, but expands to 2 __bswap32_var()'s. 123 */ 124 return (__bswap64_gen(_x)); 125 #endif 126 } 127 128 #define __htonl(x) __bswap32(x) 129 #define __htons(x) __bswap16(x) 130 #define __ntohl(x) __bswap32(x) 131 #define __ntohs(x) __bswap16(x) 132 133 #endif /* !_MACHINE_ENDIAN_H_ */ 134