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Add some bitmap operation macros similar to fd_set. Unfortunately we cannot 

re-use bitstring, because it is userland only.
This commit is contained in:
christos 2012-12-01 15:03:47 +00:00
parent 6da0cd6163
commit cd5e10b5a9
1 changed files with 36 additions and 5 deletions
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41
sys/sys/bitops.h
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@ -1,4 +1,4 @@
/* $NetBSD: bitops.h,v 1.9 2011/07/30 16:35:58 christos Exp $ */
/* $NetBSD: bitops.h,v 1.10 2012/12/01 15:03:47 christos Exp $ */
/*-
* Copyright (c) 2007, 2010 The NetBSD Foundation, Inc.
@ -188,9 +188,7 @@ fls64(uint64_t _n)
* version written by David Howells.
*/
#define _ilog2_helper(_n, _x) ((_n) & (1ULL << (_x))) ? _x :
#define ilog2(_n) \
( \
__builtin_constant_p(_n) ? ( \
#define _ilog2_const(_n) ( \
_ilog2_helper(_n, 63) \
_ilog2_helper(_n, 62) \
_ilog2_helper(_n, 61) \
@ -255,7 +253,12 @@ fls64(uint64_t _n)
_ilog2_helper(_n, 2) \
_ilog2_helper(_n, 1) \
_ilog2_helper(_n, 0) \
-1) : ((sizeof(_n) > 4 ? fls64(_n) : fls32(_n)) - 1) \
-1)
#define ilog2(_n) \
( \
__builtin_constant_p(_n) ? _ilog2_const(_n) : \
((sizeof(_n) > 4 ? fls64(_n) : fls32(_n)) - 1) \
)
static __inline void
@ -291,4 +294,32 @@ fast_remainder32(uint32_t _v, uint32_t _div, uint32_t _m, uint8_t _s1,
return _v - _div * fast_divide32(_v, _div, _m, _s1, _s2);
}
#define __BITMAP_BITS(__t) (sizeof(__t) * NBBY)
#define __BITMAP_SHIFT(__t) (ilog2(__BITMAP_BITS(__t)))
#define __BITMAP_MASK(__t) (__BITMAP_BITS(__t) - 1)
#define __BITMAP_SIZE(__t, __n) \
(((__n) + (__BITMAP_BITS(__t) - 1)) / __BITMAP_BITS(__t))
#define __BITMAP_BIT(__n, __v) \
(1 << ((__n) & __BITMAP_MASK(*__v)))
#define __BITMAP_WORD(__n, __v) \
((__n) >> __BITMAP_SHIFT(*__v))
#define __BITMAP_SET(__n, __v) \
(__v[__BITMAP_WORD(__n, __v)] |= __BITMAP_BIT(__n, __v))
#define __BITMAP_CLR(__n, __v) \
(__v[__BITMAP_WORD(__n, __v)] &= ~__BITMAP_BIT(__n, __v))
#define __BITMAP_ISSET(__n, __v) \
(__v[__BITMAP_WORD(__n, __v)] & __BITMAP_BIT(__n, __v))
#if __GNUC_PREREQ__(2, 95)
#define __BITMAP_ZERO(__v) \
(void)__builtin_memset((__v), 0, sizeof(__v))
#else
#define __BITMAP_ZERO(__v) do { \
size_t __i; \
for (__i = 0; __i < __arraycount(__v); __i++) \
(__v)[__i] = 0; \
} while (/* CONSTCOND */ 0)
#endif /* GCC 2.95 */
#endif /* _SYS_BITOPS_H_ */