/* Macros to swap the order of bytes in integer values. m68k version. Copyright (C) 1997 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 Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #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 __v; \ if (__builtin_constant_p (x)) \ __v = __bswap_constant_32 (x); \ else \ __asm__ __volatile__ ("ror%.w %#8, %0;" \ "swap %0;" \ "ror%.w %#8, %0" \ : "=d" (__v) \ : "0" (x)); \ __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]; } __v, __r; \ __v.__ll = (x); \ __r.__l[0] = __bswap_32 (__v.__l[1]); \ __r.__l[1] = __bswap_32 (__v.__l[0]); \ __r.__ll; }) #endif #endif /* bits/byteswap.h */