compiler-rt/lib/builtins/int_endianness.h

/* ===-- int_endianness.h - configuration header for compiler-rt ------------===
 *
 *		       The LLVM Compiler Infrastructure
 *
 * This file is dual licensed under the MIT and the University of Illinois Open
 * Source Licenses. See LICENSE.TXT for details.
 *
 * ===----------------------------------------------------------------------===
 *
 * This file is a configuration header for compiler-rt.
 * This file is not part of the interface of this library.
 *
 * ===----------------------------------------------------------------------===
 */

#ifndef INT_ENDIANNESS_H
#define INT_ENDIANNESS_H

#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
    defined(__ORDER_LITTLE_ENDIAN__)

/* Clang and GCC provide built-in endianness definitions. */
#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#define _YUGA_LITTLE_ENDIAN 0
#define _YUGA_BIG_ENDIAN    1
#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define _YUGA_LITTLE_ENDIAN 1
#define _YUGA_BIG_ENDIAN    0
#endif /* __BYTE_ORDER__ */

#else /* Compilers other than Clang or GCC. */

#if defined(__SVR4) && defined(__sun)
#include <sys/byteorder.h>

#if defined(_BIG_ENDIAN)
#define _YUGA_LITTLE_ENDIAN 0
#define _YUGA_BIG_ENDIAN    1
#elif defined(_LITTLE_ENDIAN)
#define _YUGA_LITTLE_ENDIAN 1
#define _YUGA_BIG_ENDIAN    0
#else /* !_LITTLE_ENDIAN */
#error "unknown endianness"
#endif /* !_LITTLE_ENDIAN */

#endif /* Solaris and AuroraUX. */

/* .. */

#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__DragonFly__) ||   \
    defined(__minix)
#include <sys/endian.h>

#if _BYTE_ORDER == _BIG_ENDIAN
#define _YUGA_LITTLE_ENDIAN 0
#define _YUGA_BIG_ENDIAN    1
#elif _BYTE_ORDER == _LITTLE_ENDIAN
#define _YUGA_LITTLE_ENDIAN 1
#define _YUGA_BIG_ENDIAN    0
#endif /* _BYTE_ORDER */

#endif /* *BSD */

#if defined(__OpenBSD__) || defined(__Bitrig__)
#include <machine/endian.h>

#if _BYTE_ORDER == _BIG_ENDIAN
#define _YUGA_LITTLE_ENDIAN 0
#define _YUGA_BIG_ENDIAN    1
#elif _BYTE_ORDER == _LITTLE_ENDIAN
#define _YUGA_LITTLE_ENDIAN 1
#define _YUGA_BIG_ENDIAN    0
#endif /* _BYTE_ORDER */

#endif /* OpenBSD and Bitrig. */

/* .. */

/* Mac OSX has __BIG_ENDIAN__ or __LITTLE_ENDIAN__ automatically set by the
 * compiler (at least with GCC) */
#if defined(__APPLE__) || defined(__ellcc__ )

#ifdef __BIG_ENDIAN__
#if __BIG_ENDIAN__
#define _YUGA_LITTLE_ENDIAN 0
#define _YUGA_BIG_ENDIAN    1
#endif
#endif /* __BIG_ENDIAN__ */

#ifdef __LITTLE_ENDIAN__
#if __LITTLE_ENDIAN__
#define _YUGA_LITTLE_ENDIAN 1
#define _YUGA_BIG_ENDIAN    0
#endif
#endif /* __LITTLE_ENDIAN__ */

#endif /* Mac OSX */

/* .. */

#if defined(_WIN32)

#define _YUGA_LITTLE_ENDIAN 1
#define _YUGA_BIG_ENDIAN    0

#endif /* Windows */

#endif /* Clang or GCC. */

/* . */

#if !defined(_YUGA_LITTLE_ENDIAN) || !defined(_YUGA_BIG_ENDIAN)
#error Unable to determine endian
#endif /* Check we found an endianness correctly. */

#endif /* INT_ENDIANNESS_H */