1#ifndef _LINUX_BYTEORDER_SWABB_H 2#define _LINUX_BYTEORDER_SWABB_H 3 4/* 5 * linux/byteorder/swabb.h 6 * SWAp Bytes Bizarrely 7 * swaHHXX[ps]?(foo) 8 * 9 * Support for obNUXIous pdp-endian and other bizarre architectures. 10 * Will Linux ever run on such ancient beasts? if not, this file 11 * will be but a programming pearl. Still, it's a reminder that we 12 * shouldn't be making too many assumptions when trying to be portable. 13 * 14 */ 15 16/* 17 * Meaning of the names I chose (vaxlinux people feel free to correct them): 18 * swahw32 swap 16-bit half-words in a 32-bit word 19 * swahb32 swap 8-bit halves of each 16-bit half-word in a 32-bit word 20 * 21 * No 64-bit support yet. I don't know NUXI conventions for long longs. 22 * I guarantee it will be a mess when it's there, though :-> 23 * It will be even worse if there are conflicting 64-bit conventions. 24 * Hopefully, no one ever used 64-bit objects on NUXI machines. 25 * 26 */ 27 28#define ___swahw32(x) \ 29({ \ 30 __u32 __x = (x); \ 31 ((__u32)( \ 32 (((__u32)(__x) & (__u32)0x0000ffffUL) << 16) | \ 33 (((__u32)(__x) & (__u32)0xffff0000UL) >> 16) )); \ 34}) 35#define ___swahb32(x) \ 36({ \ 37 __u32 __x = (x); \ 38 ((__u32)( \ 39 (((__u32)(__x) & (__u32)0x00ff00ffUL) << 8) | \ 40 (((__u32)(__x) & (__u32)0xff00ff00UL) >> 8) )); \ 41}) 42 43#define ___constant_swahw32(x) \ 44 ((__u32)( \ 45 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \ 46 (((__u32)(x) & (__u32)0xffff0000UL) >> 16) )) 47#define ___constant_swahb32(x) \ 48 ((__u32)( \ 49 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \ 50 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8) )) 51 52/* 53 * provide defaults when no architecture-specific optimization is detected 54 */ 55#ifndef __arch__swahw32 56# define __arch__swahw32(x) ___swahw32(x) 57#endif 58#ifndef __arch__swahb32 59# define __arch__swahb32(x) ___swahb32(x) 60#endif 61 62#ifndef __arch__swahw32p 63# define __arch__swahw32p(x) __swahw32(*(x)) 64#endif 65#ifndef __arch__swahb32p 66# define __arch__swahb32p(x) __swahb32(*(x)) 67#endif 68 69#ifndef __arch__swahw32s 70# define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0) 71#endif 72#ifndef __arch__swahb32s 73# define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0) 74#endif 75 76 77/* 78 * Allow constant folding 79 */ 80#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__) 81# define __swahw32(x) \ 82(__builtin_constant_p((__u32)(x)) ? \ 83 ___swahw32((x)) : \ 84 __fswahw32((x))) 85# define __swahb32(x) \ 86(__builtin_constant_p((__u32)(x)) ? \ 87 ___swahb32((x)) : \ 88 __fswahb32((x))) 89#else 90# define __swahw32(x) __fswahw32(x) 91# define __swahb32(x) __fswahb32(x) 92#endif /* OPTIMIZE */ 93 94 95static __inline__ __const__ __u32 __fswahw32(__u32 x) 96{ 97 return __arch__swahw32(x); 98} 99static __inline__ __u32 __swahw32p(__u32 *x) 100{ 101 return __arch__swahw32p(x); 102} 103static __inline__ void __swahw32s(__u32 *addr) 104{ 105 __arch__swahw32s(addr); 106} 107 108 109static __inline__ __const__ __u32 __fswahb32(__u32 x) 110{ 111 return __arch__swahb32(x); 112} 113static __inline__ __u32 __swahb32p(__u32 *x) 114{ 115 return __arch__swahb32p(x); 116} 117static __inline__ void __swahb32s(__u32 *addr) 118{ 119 __arch__swahb32s(addr); 120} 121 122#ifdef __BYTEORDER_HAS_U64__ 123/* 124 * Not supported yet 125 */ 126#endif /* __BYTEORDER_HAS_U64__ */ 127 128#if defined(__KERNEL__) 129#define swahw32 __swahw32 130#define swahb32 __swahb32 131#define swahw32p __swahw32p 132#define swahb32p __swahb32p 133#define swahw32s __swahw32s 134#define swahb32s __swahb32s 135#endif 136 137#endif /* _LINUX_BYTEORDER_SWABB_H */ 138