endswap.h

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/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2012-2016  Xiph.org Foundation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* It is assumed that this header will be included after "config.h". */

#if HAVE_BSWAP32            /* GCC and Clang */

/* GCC prior to 4.8 didn't provide bswap16 on x86_64 */
#if ! HAVE_BSWAP16
static inline unsigned short __builtin_bswap16(unsigned short a)
{
    return (a<<8)|(a>>8);
}
#endif

#define ENDSWAP_16(x)       (__builtin_bswap16 (x))
#define ENDSWAP_32(x)       (__builtin_bswap32 (x))
#define ENDSWAP_64(x)       (__builtin_bswap64 (x))

#elif defined _MSC_VER      /* Windows */

#include <stdlib.h>

#define ENDSWAP_16(x)       (_byteswap_ushort (x))
#define ENDSWAP_32(x)       (_byteswap_ulong (x))
#define ENDSWAP_64(x)       (_byteswap_uint64 (x))

#elif defined HAVE_BYTESWAP_H       /* Linux */

#include <byteswap.h>

#define ENDSWAP_16(x)       (bswap_16 (x))
#define ENDSWAP_32(x)       (bswap_32 (x))
#define ENDSWAP_64(x)       (bswap_64 (x))

#else

#define ENDSWAP_16(x)       ((((x) >> 8) & 0xFF) | (((x) & 0xFF) << 8))
#define ENDSWAP_32(x)       ((((x) >> 24) & 0xFF) | (((x) >> 8) & 0xFF00) | (((x) & 0xFF00) << 8) | (((x) & 0xFF) << 24))
#define ENDSWAP_64(x)       ((ENDSWAP_32(((x) >> 32) & 0xFFFFFFFF)) | (ENDSWAP_32((x) & 0xFFFFFFFF) << 32))

#endif


/* Host to little-endian byte swapping (for MD5 calculation) */
#if CPU_IS_BIG_ENDIAN

#define H2LE_16(x)      ENDSWAP_16 (x)
#define H2LE_32(x)      ENDSWAP_32 (x)

#else

#define H2LE_16(x)      (x)
#define H2LE_32(x)      (x)

#endif