[src/trunk]: src/sys/sys Add some bitmap operation macros similar to fd_set. ...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/54ca079bc6da
branches:  trunk
changeset: 783009:54ca079bc6da
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Dec 01 15:03:47 2012 +0000

description:
Add some bitmap operation macros similar to fd_set. Unfortunately we cannot
re-use bitstring, because it is userland only.

diffstat:

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

diffs (67 lines):

diff -r f0db7bb48216 -r 54ca079bc6da sys/sys/bitops.h
--- a/sys/sys/bitops.h  Sat Dec 01 13:28:18 2012 +0000
+++ b/sys/sys/bitops.h  Sat Dec 01 15:03:47 2012 +0000
@@ -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 @@
  * 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 @@
        _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 @@
        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_ */