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Direktori : /proc/self/root/proc/thread-self/root/usr/include/bits/ |
Current File : //proc/self/root/proc/thread-self/root/usr/include/bits/byteswap.h |
/* Macros to swap the order of bytes in integer values. Copyright (C) 1997-2012 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, see <http://www.gnu.org/licenses/>. */ #if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead." #endif #ifndef _BITS_BYTESWAP_H #define _BITS_BYTESWAP_H 1 #include <features.h> #include <bits/types.h> #include <bits/wordsize.h> /* Swap bytes in 16 bit value. */ #define __bswap_constant_16(x) \ ((unsigned short int) ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))) /* Get __bswap_16. */ #include <bits/byteswap-16.h> /* Swap bytes in 32 bit value. */ #define __bswap_constant_32(x) \ ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \ (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24)) #ifdef __GNUC__ # if __GNUC_PREREQ (4, 3) static __inline unsigned int __bswap_32 (unsigned int __bsx) { return __builtin_bswap32 (__bsx); } # elif __GNUC__ >= 2 # if __WORDSIZE == 64 || (defined __i486__ || defined __pentium__ \ || defined __pentiumpro__ || defined __pentium4__ \ || defined __k8__ || defined __athlon__ \ || defined __k6__ || defined __nocona__ \ || defined __core2__ || defined __geode__ \ || defined __amdfam10__) /* To swap the bytes in a word the i486 processors and up provide the `bswap' opcode. On i386 we have to use three instructions. */ # define __bswap_32(x) \ (__extension__ \ ({ unsigned int __v, __x = (x); \ if (__builtin_constant_p (__x)) \ __v = __bswap_constant_32 (__x); \ else \ __asm__ ("bswap %0" : "=r" (__v) : "0" (__x)); \ __v; })) # else # define __bswap_32(x) \ (__extension__ \ ({ unsigned int __v, __x = (x); \ if (__builtin_constant_p (__x)) \ __v = __bswap_constant_32 (__x); \ else \ __asm__ ("rorw $8, %w0;" \ "rorl $16, %0;" \ "rorw $8, %w0" \ : "=r" (__v) \ : "0" (__x) \ : "cc"); \ __v; })) # endif # else # define __bswap_32(x) \ (__extension__ \ ({ unsigned int __x = (x); __bswap_constant_32 (__x); })) # endif #else static __inline unsigned int __bswap_32 (unsigned int __bsx) { return __bswap_constant_32 (__bsx); } #endif #if __GNUC_PREREQ (2, 0) /* Swap bytes in 64 bit value. */ # define __bswap_constant_64(x) \ (__extension__ ((((x) & 0xff00000000000000ull) >> 56) \ | (((x) & 0x00ff000000000000ull) >> 40) \ | (((x) & 0x0000ff0000000000ull) >> 24) \ | (((x) & 0x000000ff00000000ull) >> 8) \ | (((x) & 0x00000000ff000000ull) << 8) \ | (((x) & 0x0000000000ff0000ull) << 24) \ | (((x) & 0x000000000000ff00ull) << 40) \ | (((x) & 0x00000000000000ffull) << 56))) # if __GNUC_PREREQ (4, 3) static __inline __uint64_t __bswap_64 (__uint64_t __bsx) { return __builtin_bswap64 (__bsx); } # elif __WORDSIZE == 64 # define __bswap_64(x) \ (__extension__ \ ({ __uint64_t __v, __x = (x); \ if (__builtin_constant_p (__x)) \ __v = __bswap_constant_64 (__x); \ else \ __asm__ ("bswap %q0" : "=r" (__v) : "0" (__x)); \ __v; })) # else # define __bswap_64(x) \ (__extension__ \ ({ union { __extension__ __uint64_t __ll; \ unsigned int __l[2]; } __w, __r; \ if (__builtin_constant_p (x)) \ __r.__ll = __bswap_constant_64 (x); \ else \ { \ __w.__ll = (x); \ __r.__l[0] = __bswap_32 (__w.__l[1]); \ __r.__l[1] = __bswap_32 (__w.__l[0]); \ } \ __r.__ll; })) # endif #elif __GLIBC_HAVE_LONG_LONG # define __bswap_constant_64(x) \ ((((x) & 0xff00000000000000ull) >> 56) \ | (((x) & 0x00ff000000000000ull) >> 40) \ | (((x) & 0x0000ff0000000000ull) >> 24) \ | (((x) & 0x000000ff00000000ull) >> 8) \ | (((x) & 0x00000000ff000000ull) << 8) \ | (((x) & 0x0000000000ff0000ull) << 24) \ | (((x) & 0x000000000000ff00ull) << 40) \ | (((x) & 0x00000000000000ffull) << 56)) static __inline __uint64_t __bswap_64 (__uint64_t __bsx) { return __bswap_constant_64 (__bsx); } #endif #endif /* _BITS_BYTESWAP_H */