1/*      $NetBSD: bswap.h,v 1.19 2015/03/12 15:28:16 christos Exp $      */
 2
 3/* Written by Manuel Bouyer. Public domain */
 4
 5#ifndef _SYS_BSWAP_H_
 6#define _SYS_BSWAP_H_
 7
 8#ifndef _LOCORE
 9#include <sys/stdint.h>
10
11#include <machine/bswap.h>
12
13__BEGIN_DECLS
14/* Always declare the functions in case their address is taken (etc) */
15#if defined(_KERNEL) || defined(_STANDALONE) || !defined(__BSWAP_RENAME)
16uint16_t bswap16(uint16_t) __constfunc;
17uint32_t bswap32(uint32_t) __constfunc;
18#else
19uint16_t bswap16(uint16_t) __RENAME(__bswap16) __constfunc;
20uint32_t bswap32(uint32_t) __RENAME(__bswap32) __constfunc;
21#endif
22uint64_t bswap64(uint64_t) __constfunc;
23__END_DECLS
24
25#if defined(__GNUC__) && !defined(__lint__)
26
27/* machine/byte_swap.h might have defined inline versions */
28#ifndef __BYTE_SWAP_U64_VARIABLE
29#define	__BYTE_SWAP_U64_VARIABLE bswap64
30#endif
31
32#ifndef __BYTE_SWAP_U32_VARIABLE
33#define	__BYTE_SWAP_U32_VARIABLE bswap32
34#endif
35
36#ifndef __BYTE_SWAP_U16_VARIABLE
37#define	__BYTE_SWAP_U16_VARIABLE bswap16
38#endif
39
40#define	__byte_swap_u64_constant(x) \
41	(__CAST(uint64_t, \
42	 ((((x) & 0xff00000000000000ull) >> 56) | \
43	  (((x) & 0x00ff000000000000ull) >> 40) | \
44	  (((x) & 0x0000ff0000000000ull) >> 24) | \
45	  (((x) & 0x000000ff00000000ull) >>  8) | \
46	  (((x) & 0x00000000ff000000ull) <<  8) | \
47	  (((x) & 0x0000000000ff0000ull) << 24) | \
48	  (((x) & 0x000000000000ff00ull) << 40) | \
49	  (((x) & 0x00000000000000ffull) << 56))))
50
51#define	__byte_swap_u32_constant(x) \
52	(__CAST(uint32_t, \
53	((((x) & 0xff000000) >> 24) | \
54	 (((x) & 0x00ff0000) >>  8) | \
55	 (((x) & 0x0000ff00) <<  8) | \
56	 (((x) & 0x000000ff) << 24))))
57
58#define	__byte_swap_u16_constant(x) \
59	(__CAST(uint16_t, \
60	((((x) & 0xff00) >> 8) | \
61	 (((x) & 0x00ff) << 8))))
62
63#define	bswap64(x) \
64	__CAST(uint64_t, __builtin_constant_p((x)) ? \
65	 __byte_swap_u64_constant(x) : __BYTE_SWAP_U64_VARIABLE(x))
66
67#define	bswap32(x) \
68	__CAST(uint32_t, __builtin_constant_p((x)) ? \
69	 __byte_swap_u32_constant(x) : __BYTE_SWAP_U32_VARIABLE(x))
70
71#define	bswap16(x) \
72	__CAST(uint16_t, __builtin_constant_p((x)) ? \
73	 __byte_swap_u16_constant(x) : __BYTE_SWAP_U16_VARIABLE(x))
74
75#endif /* __GNUC__ && !__lint__ */
76#endif /* !_LOCORE */
77
78#endif /* !_SYS_BSWAP_H_ */