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authorchristos <christos@NetBSD.org>2012-03-13 21:07:28 +0000
committerchristos <christos@NetBSD.org>2012-03-13 21:07:28 +0000
commitdc654a7d2d7cf5bb66c22d38f400a8cb6d03a45a (patch)
tree66f09bbf188f893f1aa746df90f76dc7ba6f3933
parentce4cd1027e818e6aa4e5529170d41b6a64b3abb0 (diff)
Type macros providing min and max values for the given type, plus one that
returns if a value can be represented in a given type.
-rw-r--r--sys/sys/cdefs.h30
1 files changed, 29 insertions, 1 deletions
diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index 2bf94f145a9..60082609e24 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -1,4 +1,4 @@
-/* $NetBSD: cdefs.h,v 1.92 2012/02/22 17:52:58 martin Exp $ */
+/* $NetBSD: cdefs.h,v 1.93 2012/03/13 21:07:28 christos Exp $ */
/*
* Copyright (c) 1991, 1993
@@ -530,4 +530,32 @@
#define __CAST(__dt, __st) ((__dt)(__st))
#endif
+#define __type_mask(t) (/*LINTED*/sizeof(t) < sizeof(intmax_t) ? \
+ (~((1ULL << (sizeof(t) * NBBY)) - 1)) : 0ULL)
+
+static inline long long __zero(void) { return 0; }
+static __inline int __negative(double x) { return x < 0; }
+
+#define __type_min_s(t) ((t)((1ULL << (sizeof(t) * NBBY - 1))))
+#define __type_max_s(t) ((t)~((1ULL << (sizeof(t) * NBBY - 1))))
+#define __type_min_u(t) ((t)0ULL)
+#define __type_max_u(t) ((t)~0ULL)
+#define __type_is_signed(t) (/*LINTED*/__type_min_s(t) + (t)1 < (t)1)
+#define __type_min(t) (__type_is_signed(t) ? __type_min_s(t) : __type_min_u(t))
+#define __type_max(t) (__type_is_signed(t) ? __type_max_s(t) : __type_max_u(t))
+
+
+#define __type_fit_u(t, a) (/*LINTED*/sizeof(t) < sizeof(intmax_t) ? \
+ (((a) & __type_mask(t)) == 0) : !__negative(a))
+
+#define __type_fit_s(t, a) (/*LINTED*/__negative(a) ? \
+ ((intmax_t)((a) + __zero()) >= (intmax_t)__type_min_s(t)) : \
+ ((intmax_t)((a) + __zero()) <= (intmax_t)__type_max_s(t)))
+
+/*
+ * return true if value 'a' fits in type 't'
+ */
+#define __type_fit(t, a) (__type_is_signed(t) ? \
+ __type_fit_s(t, a) : __type_fit_u(t, a))
+
#endif /* !_SYS_CDEFS_H_ */