/*-------------------------------------------------------------------------
 *
 * pg_bswap.h
 *	  Byte swapping.
 *
 * Macros for reversing the byte order of 32-bit and 64-bit unsigned integers.
 * For example, 0xAABBCCDD becomes 0xDDCCBBAA.  These are just wrappers for
 * built-in functions provided by the compiler where support exists.
 *
 * Note that the GCC built-in functions __builtin_bswap32() and
 * __builtin_bswap64() are documented as accepting single arguments of type
 * uint32_t and uint64_t respectively (these are also the respective return
 * types).  Use caution when using these wrapper macros with signed integers.
 *
 * Copyright (c) 2015, PostgreSQL Global Development Group
 *
 * src/include/port/pg_bswap.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_BSWAP_H
#define PG_BSWAP_H

#ifdef HAVE__BUILTIN_BSWAP32
#define BSWAP32(x) __builtin_bswap32(x)
#else
#define BSWAP32(x) (((x << 24) & 0xff000000) | \
					((x << 8) & 0x00ff0000) | \
					((x >> 8) & 0x0000ff00) | \
					((x >> 24) & 0x000000ff))
#endif	/* HAVE__BUILTIN_BSWAP32 */

#ifdef HAVE__BUILTIN_BSWAP64
#define BSWAP64(x) __builtin_bswap64(x)
#else
#define BSWAP64(x) (((x << 56) & 0xff00000000000000UL) | \
					((x << 40) & 0x00ff000000000000UL) | \
					((x << 24) & 0x0000ff0000000000UL) | \
					((x << 8) & 0x000000ff00000000UL) | \
					((x >> 8) & 0x00000000ff000000UL) | \
					((x >> 24) & 0x0000000000ff0000UL) | \
					((x >> 40) & 0x000000000000ff00UL) | \
					((x >> 56) & 0x00000000000000ffUL))
#endif	/* HAVE__BUILTIN_BSWAP64 */

#endif   /* PG_BSWAP_H */