| 1 | /* Macros to swap the order of bytes in integer values. |
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| 2 | Copyright (C) 1997, 1998, 2000, 2001, 2002 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, write to the Free |
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| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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| 18 | 02111-1307 USA. */ |
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| 19 | |
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| 20 | #if !defined _BYTESWAP_H && !defined _NETINET_IN_H |
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| 21 | # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead." |
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| 22 | #endif |
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| 23 | |
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| 24 | #ifndef _BITS_BYTESWAP_H |
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| 25 | #define _BITS_BYTESWAP_H 1 |
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| 26 | |
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| 27 | /* Swap bytes in 16 bit value. */ |
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| 28 | #ifdef __GNUC__ |
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| 29 | # define __bswap_16(x) \ |
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| 30 | (__extension__ \ |
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| 31 | ({ unsigned short int __bsx = (x); \ |
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| 32 | ((((__bsx) >> 8) & 0xff) | (((__bsx) & 0xff) << 8)); })) |
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| 33 | #else |
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| 34 | static __inline unsigned short int |
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| 35 | __bswap_16 (unsigned short int __bsx) |
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| 36 | { |
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| 37 | return ((((__bsx) >> 8) & 0xff) | (((__bsx) & 0xff) << 8)); |
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| 38 | } |
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| 39 | #endif |
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| 40 | |
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| 41 | /* Swap bytes in 32 bit value. */ |
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| 42 | #ifdef __GNUC__ |
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| 43 | # define __bswap_32(x) \ |
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| 44 | (__extension__ \ |
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| 45 | ({ unsigned int __bsx = (x); \ |
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| 46 | ((((__bsx) & 0xff000000) >> 24) | (((__bsx) & 0x00ff0000) >> 8) | \ |
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| 47 | (((__bsx) & 0x0000ff00) << 8) | (((__bsx) & 0x000000ff) << 24)); })) |
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| 48 | #else |
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| 49 | static __inline unsigned int |
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| 50 | __bswap_32 (unsigned int __bsx) |
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| 51 | { |
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| 52 | return ((((__bsx) & 0xff000000) >> 24) | (((__bsx) & 0x00ff0000) >> 8) | |
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| 53 | (((__bsx) & 0x0000ff00) << 8) | (((__bsx) & 0x000000ff) << 24)); |
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| 54 | } |
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| 55 | #endif |
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| 56 | |
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| 57 | #if defined __GNUC__ && __GNUC__ >= 2 |
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| 58 | /* Swap bytes in 64 bit value. */ |
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| 59 | # define __bswap_constant_64(x) \ |
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| 60 | ((((x) & 0xff00000000000000ull) >> 56) \ |
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| 61 | | (((x) & 0x00ff000000000000ull) >> 40) \ |
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| 62 | | (((x) & 0x0000ff0000000000ull) >> 24) \ |
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| 63 | | (((x) & 0x000000ff00000000ull) >> 8) \ |
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| 64 | | (((x) & 0x00000000ff000000ull) << 8) \ |
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| 65 | | (((x) & 0x0000000000ff0000ull) << 24) \ |
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| 66 | | (((x) & 0x000000000000ff00ull) << 40) \ |
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| 67 | | (((x) & 0x00000000000000ffull) << 56)) |
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| 68 | |
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| 69 | # define __bswap_64(x) \ |
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| 70 | (__extension__ \ |
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| 71 | ({ union { __extension__ unsigned long long int __ll; \ |
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| 72 | unsigned int __l[2]; } __w, __r; \ |
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| 73 | if (__builtin_constant_p (x)) \ |
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| 74 | __r.__ll = __bswap_constant_64 (x); \ |
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| 75 | else \ |
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| 76 | { \ |
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| 77 | __w.__ll = (x); \ |
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| 78 | __r.__l[0] = __bswap_32 (__w.__l[1]); \ |
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| 79 | __r.__l[1] = __bswap_32 (__w.__l[0]); \ |
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| 80 | } \ |
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| 81 | __r.__ll; })) |
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| 82 | #endif |
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| 83 | |
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| 84 | #endif /* _BITS_BYTESWAP_H */ |
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