/* Macros to swap the order of bytes in integer values. m68k version. Copyright (C) 1997, 2002 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #if !defined _BYTESWAP_H && !defined _NETINET_IN_H # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead." #endif #ifndef _BITS_BYTESWAP_H #define _BITS_BYTESWAP_H 1 /* Swap bytes in 16 bit value. We don't provide an assembler version because GCC is smart enough to generate optimal assembler output, and this allows for better cse. */ #define __bswap_16(x) \ ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8)) /* Swap bytes in 32 bit value. */ #define __bswap_constant_32(x) \ ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \ (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24)) #if defined __GNUC__ && __GNUC__ >= 2 # define __bswap_32(x) \ __extension__ \ ({ unsigned int __bswap_32_v; \ if (__builtin_constant_p (x)) \ __bswap_32_v = __bswap_constant_32 (x); \ else \ __asm__ __volatile__ ("ror%.w %#8, %0;" \ "swap %0;" \ "ror%.w %#8, %0" \ : "=d" (__bswap_32_v) \ : "0" ((unsigned int) (x))); \ __bswap_32_v; }) #else # define __bswap_32(x) __bswap_constant_32 (x) #endif #if defined __GNUC__ && __GNUC__ >= 2 /* Swap bytes in 64 bit value. */ # define __bswap_64(x) \ __extension__ \ ({ union { unsigned long long int __ll; \ unsigned long int __l[2]; } __bswap_64_v, __bswap_64_r; \ __bswap_64_v.__ll = (x); \ __bswap_64_r.__l[0] = __bswap_32 (__bswap_64_v.__l[1]); \ __bswap_64_r.__l[1] = __bswap_32 (__bswap_64_v.__l[0]); \ __bswap_64_r.__ll; }) #endif #endif /* _BITS_BYTESWAP_H */