From cd5e10b5a9894a7278e2c692b4b01e975db6b48c Mon Sep 17 00:00:00 2001
From: christos <christos@NetBSD.org>
Date: Sat, 1 Dec 2012 15:03:47 +0000
Subject: [PATCH] Add some bitmap operation macros similar to fd_set.
 Unfortunately we cannot re-use bitstring, because it is userland only.

---
 sys/sys/bitops.h | 41 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/sys/sys/bitops.h b/sys/sys/bitops.h
index 6a086300f524..44bd522db2ca 100644
--- a/sys/sys/bitops.h
+++ b/sys/sys/bitops.h
@@ -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_ */