136 строки
3.0 KiB
C
136 строки
3.0 KiB
C
#ifndef _LINUX_BYTEORDER_SWABB_H
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#define _LINUX_BYTEORDER_SWABB_H
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/*
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* linux/byteorder/swabb.h
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* SWAp Bytes Bizarrely
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* swaHHXX[ps]?(foo)
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*
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* Support for obNUXIous pdp-endian and other bizarre architectures.
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* Will Linux ever run on such ancient beasts? if not, this file
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* will be but a programming pearl. Still, it's a reminder that we
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* shouldn't be making too many assumptions when trying to be portable.
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*
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*/
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/*
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* Meaning of the names I chose (vaxlinux people feel free to correct them):
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* swahw32 swap 16-bit half-words in a 32-bit word
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* swahb32 swap 8-bit halves of each 16-bit half-word in a 32-bit word
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*
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* No 64-bit support yet. I don't know NUXI conventions for long longs.
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* I guarantee it will be a mess when it's there, though :->
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* It will be even worse if there are conflicting 64-bit conventions.
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* Hopefully, no one ever used 64-bit objects on NUXI machines.
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*
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*/
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#include <linux/types.h>
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#define ___swahw32(x) \
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({ \
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__u32 __x = (x); \
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((__u32)( \
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(((__u32)(__x) & (__u32)0x0000ffffUL) << 16) | \
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(((__u32)(__x) & (__u32)0xffff0000UL) >> 16) )); \
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})
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#define ___swahb32(x) \
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({ \
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__u32 __x = (x); \
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((__u32)( \
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(((__u32)(__x) & (__u32)0x00ff00ffUL) << 8) | \
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(((__u32)(__x) & (__u32)0xff00ff00UL) >> 8) )); \
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})
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#define ___constant_swahw32(x) \
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((__u32)( \
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(((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
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(((__u32)(x) & (__u32)0xffff0000UL) >> 16) ))
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#define ___constant_swahb32(x) \
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((__u32)( \
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(((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \
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(((__u32)(x) & (__u32)0xff00ff00UL) >> 8) ))
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/*
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* provide defaults when no architecture-specific optimization is detected
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*/
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#ifndef __arch__swahw32
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# define __arch__swahw32(x) ___swahw32(x)
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#endif
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#ifndef __arch__swahb32
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# define __arch__swahb32(x) ___swahb32(x)
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#endif
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#ifndef __arch__swahw32p
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# define __arch__swahw32p(x) __swahw32(*(x))
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#endif
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#ifndef __arch__swahb32p
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# define __arch__swahb32p(x) __swahb32(*(x))
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#endif
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#ifndef __arch__swahw32s
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# define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0)
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#endif
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#ifndef __arch__swahb32s
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# define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0)
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#endif
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/*
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* Allow constant folding
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*/
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#define __swahw32(x) \
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(__builtin_constant_p((__u32)(x)) ? \
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___swahw32((x)) : \
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__fswahw32((x)))
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#define __swahb32(x) \
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(__builtin_constant_p((__u32)(x)) ? \
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___swahb32((x)) : \
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__fswahb32((x)))
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static inline __u32 __fswahw32(__u32 x)
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{
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return __arch__swahw32(x);
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}
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static inline __u32 __swahw32p(__u32 *x)
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{
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return __arch__swahw32p(x);
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}
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static inline void __swahw32s(__u32 *addr)
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{
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__arch__swahw32s(addr);
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}
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static inline __u32 __fswahb32(__u32 x)
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{
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return __arch__swahb32(x);
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}
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static inline __u32 __swahb32p(__u32 *x)
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{
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return __arch__swahb32p(x);
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}
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static inline void __swahb32s(__u32 *addr)
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{
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__arch__swahb32s(addr);
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}
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#ifdef __BYTEORDER_HAS_U64__
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/*
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* Not supported yet
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*/
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#endif /* __BYTEORDER_HAS_U64__ */
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#define swahw32 __swahw32
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#define swahb32 __swahb32
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#define swahw32p __swahw32p
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#define swahb32p __swahb32p
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#define swahw32s __swahw32s
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#define swahb32s __swahb32s
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#endif /* _LINUX_BYTEORDER_SWABB_H */
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