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43 lines
1.6 KiB
C
43 lines
1.6 KiB
C
/* Macros to swap the order of bytes in 16-bit integer values.
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Copyright (C) 1997-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _BITS_BYTESWAP_H
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# error "Never use <bits/byteswap-16.h> directly; include <byteswap.h> instead."
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#endif
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#if defined __GNUC__ && __GNUC__ >= 2
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# define __bswap_16(x) \
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(__extension__ \
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({ unsigned short int __v, __x = (unsigned short int) (x); \
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if (__builtin_constant_p (x)) \
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__v = __bswap_constant_16 (__x); \
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else \
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__asm__ __volatile__ ("shl %0 = %1, 48 ;;" \
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"mux1 %0 = %0, @rev ;;" \
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: "=r" (__v) \
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: "r" ((unsigned short int) (__x))); \
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__v; }))
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#else
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/* This is better than nothing. */
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static __inline unsigned short int
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__bswap_16 (unsigned short int __bsx)
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{
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return __bswap_constant_16 (__bsx);
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}
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#endif
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