?? swab.h
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#ifndef _LINUX_BYTEORDER_SWAB_H#define _LINUX_BYTEORDER_SWAB_H/* * linux/byteorder/swab.h * Byte-swapping, independently from CPU endianness * swabXX[ps]?(foo) * * Francois-Rene Rideau <fare@tunes.org> 19971205 * separated swab functions from cpu_to_XX, * to clean up support for bizarre-endian architectures. * * See asm-i386/byteorder.h and suches for examples of how to provide * architecture-dependent optimized versions * *//* casts are necessary for constants, because we never know how for sure * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. */#define ___swab16(x) \ ((__u16)( \ (((__u16)(x) & (__u16)0x00ffU) << 8) | \ (((__u16)(x) & (__u16)0xff00U) >> 8) ))#define ___swab32(x) \ ((__u32)( \ (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ (((__u32)(x) & (__u32)0xff000000UL) >> 24) ))#define ___swab64(x) \ ((__u64)( \ (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) ))/* * provide defaults when no architecture-specific optimization is detected */#ifndef __arch__swab16# define __arch__swab16(x) ___swab16(x)#endif#ifndef __arch__swab32# define __arch__swab32(x) ___swab32(x)#endif#ifndef __arch__swab64# define __arch__swab64(x) ___swab64(x)#endif#ifndef __arch__swab16p# define __arch__swab16p(x) __swab16(*(x))#endif#ifndef __arch__swab32p# define __arch__swab32p(x) __swab32(*(x))#endif#ifndef __arch__swab64p# define __arch__swab64p(x) __swab64(*(x))#endif#ifndef __arch__swab16s# define __arch__swab16s(x) do { *(x) = __swab16p((x)); } while (0)#endif#ifndef __arch__swab32s# define __arch__swab32s(x) do { *(x) = __swab32p((x)); } while (0)#endif#ifndef __arch__swab64s# define __arch__swab64s(x) do { *(x) = __swab64p((x)); } while (0)#endif/* * Allow constant folding */#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)# define __swab16(x) \(__builtin_constant_p((__u16)(x)) ? \ ___swab16((x)) : \ __fswab16((x)))# define __swab32(x) \(__builtin_constant_p((__u32)(x)) ? \ ___swab32((x)) : \ __fswab32((x)))# define __swab64(x) \(__builtin_constant_p((__u64)(x)) ? \ ___swab64((x)) : \ __fswab64((x)))#else# define __swab16(x) __fswab16(x)# define __swab32(x) __fswab32(x)# define __swab64(x) __fswab64(x)#endif /* OPTIMIZE */static __inline__ __attribute__((const)) __u16 __fswab16(__u16 x){ return __arch__swab16(x);}static __inline__ __u16 __swab16p(__u16 *x){ return __arch__swab16p(x);}static __inline__ void __swab16s(__u16 *addr){ __arch__swab16s(addr);}static __inline__ __attribute__((const)) __u32 __fswab32(__u32 x){ return __arch__swab32(x);}static __inline__ __u32 __swab32p(__u32 *x){ return __arch__swab32p(x);}static __inline__ void __swab32s(__u32 *addr){ __arch__swab32s(addr);}#ifdef __BYTEORDER_HAS_U64__static __inline__ __attribute__((const)) __u64 __fswab64(__u64 x){# ifdef __SWAB_64_THRU_32__ __u32 h = x >> 32; __u32 l = x & ((1ULL<<32)-1); return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h)));# else return __arch__swab64(x);# endif}static __inline__ __u64 __swab64p(__u64 *x){ return __arch__swab64p(x);}static __inline__ void __swab64s(__u64 *addr){ __arch__swab64s(addr);}#endif /* __BYTEORDER_HAS_U64__ */#if defined(__KERNEL__)#define swab16 __swab16#define swab32 __swab32#define swab64 __swab64#define swab16p __swab16p#define swab32p __swab32p#define swab64p __swab64p#define swab16s __swab16s#define swab32s __swab32s#define swab64s __swab64s#endif#endif /* _LINUX_BYTEORDER_SWAB_H */
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