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/*
*
* Reverse bytes in 2, 4 and 8 byte objects
*
* Copyright 2000 Saikat DebRoy
* 2011 R Development Core Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, a copy is available at
* http://www.r-project.org/Licenses/
*/
#ifndef SWAP_BYTES_H
#define SWAP_BYTES_H
#define swap_bytes_16(from, to) \
do { \
unsigned short __from16 = (from); \
(to) = (unsigned short) ((((__from16) >> 8) & 0xff) | (((__from16) & 0xff) << 8)); \
} while (0)
#define swap_bytes_32(from, to) \
do { \
unsigned int __from32 = (from); \
(to) = (((__from32 & 0xff000000) >> 24) | \
((__from32 & 0x00ff0000) >> 8) | \
((__from32 & 0x0000ff00) << 8) | \
((__from32 & 0x000000ff) << 24)); \
} while (0)
#define swap_bytes_double(from, to) \
do { \
union { \
unsigned int u32[2]; \
double d; \
} __from, __to; \
__from.d = (from); \
swap_bytes_32(__from.u32[1], __to.u32[0]); \
swap_bytes_32(__from.u32[0], __to.u32[1]); \
(to) = __to.d; \
} while (0)
#define swap_bytes_ushort(from, to) swap_bytes_16(from, to)
#define reverse_ushort(x) swap_bytes_16(x, x)
#define swap_bytes_short(from, to) \
do { \
union { \
unsigned short u16; \
short s16; \
} __from, __to; \
__from.s16 = (from); \
swap_bytes_16(__from.u16, __to.u16); \
(to) = __to.s16; \
} while (0)
#define reverse_short(x) \
do { \
union { \
unsigned short u16; \
short s16; \
} __from, __to; \
__from.s16 = (x); \
swap_bytes_16(__from.u16, __to.u16); \
(x) = __to.s16; \
} while(0)
#define swap_bytes_uint(from, to) swap_bytes_32(from, to)
#define reverse_uint(x) swap_bytes_32(x, x)
#define swap_bytes_int(from, to) \
do { \
union { \
unsigned int u32; \
int s32; \
} __from, __to; \
__from.s32 = (from); \
swap_bytes_32(__from.u32, __to.u32); \
(to) = __to.s32; \
} while(0)
#define reverse_int(x) \
do { \
union { \
unsigned int u32; \
int s32; \
} __from, __to; \
__from.s32 = (x); \
swap_bytes_32(__from.u32, __to.u32); \
(x) = __to.s32; \
} while(0)
#define swap_bytes_float(from, to) \
do { \
union { \
unsigned int u32; \
float f; \
} __from, __to; \
__from.f = (from); \
swap_bytes_32(__from.u32, __to.u32); \
(to) = __to.f; \
} while(0)
#define reverse_float(x) \
do { \
union { \
unsigned int u32; \
float f; \
} __from, __to; \
__from.f = (x); \
swap_bytes_32(__from.u32, __to.u32); \
(x) = __to.f; \
} while(0)
#define reverse_double(x) swap_bytes_double(x, x)
#endif /* SWAP_BYTES_H */
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