1 /* $NetBSD: byte_swap.h,v 1.6 2001/11/29 02:46:55 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #ifndef _I386_BYTE_SWAP_H_ 40 #define _I386_BYTE_SWAP_H_ 41 42 #include <sys/types.h> 43 44 #if defined(_KERNEL_OPT) 45 #include "opt_cputype.h" 46 #endif 47 48 49 static __inline u_int32_t __byte_swap_long_variable(u_int32_t); 50 static __inline u_int16_t __byte_swap_word_variable(u_int16_t); 51 52 static __inline u_int32_t 53 __byte_swap_long_variable(u_int32_t x) 54 { 55 __asm __volatile ( 56 #if defined(_KERNEL) && !defined(_LKM) && !defined(I386_CPU) 57 "bswap %1" 58 #else 59 "rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1" 60 #endif 61 : "=r" (x) : "0" (x)); 62 return (x); 63 } 64 65 static __inline u_int16_t 66 __byte_swap_word_variable(u_int16_t x) 67 { 68 __asm __volatile ("rorw $8, %w1" : "=r" (x) : "0" (x)); 69 return (x); 70 } 71 72 #ifdef __OPTIMIZE__ 73 74 #define __byte_swap_long_constant(x) \ 75 ((((x) & 0xff000000) >> 24) | \ 76 (((x) & 0x00ff0000) >> 8) | \ 77 (((x) & 0x0000ff00) << 8) | \ 78 (((x) & 0x000000ff) << 24)) 79 #define __byte_swap_word_constant(x) \ 80 ((((x) & 0xff00) >> 8) | \ 81 (((x) & 0x00ff) << 8)) 82 #define __byte_swap_long(x) \ 83 (__builtin_constant_p((x)) ? \ 84 __byte_swap_long_constant(x) : __byte_swap_long_variable(x)) 85 #define __byte_swap_word(x) \ 86 (__builtin_constant_p((x)) ? \ 87 __byte_swap_word_constant(x) : __byte_swap_word_variable(x)) 88 89 #else /* __OPTIMIZE__ */ 90 91 #define __byte_swap_long(x) __byte_swap_long_variable(x) 92 #define __byte_swap_word(x) __byte_swap_word_variable(x) 93 94 #endif /* __OPTIMIZE__ */ 95 96 #endif /* !_I386_BYTE_SWAP_H_ */ 97