int is big enough to fully represent exponents of all supported fp

formats.  which even for 80-bit & 128-bit long doubles is only 15
bits.  therefore, scalbln, scalblnf, scalblnl are essentially the
same as scalbn, scalbnf, scalbnl with bounds checking so that
LONG_MIN..INT_MIN, and INT_MAX..LONG_MAX ranges properly raise
exceptions & yield correct values.  looks good to millert@

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/libm/noieee_src/n_scalbln.c b/lib/libm/noieee_src/n_scalbln.c
new file mode 100644
index 00000000000..c1fd86a4682
--- /dev/null
+++ b/lib/libm/noieee_src/n_scalbln.c
@@ -0,0 +1,31 @@
+/*	$OpenBSD: n_scalbln.c,v 1.1 2009/07/25 11:38:10 martynas Exp $	*/
+
+/*
+ * Written by Martynas Venckus.  Public domain
+ */
+
+#include <limits.h>
+#include <math.h>
+
+double
+scalbln(double x, long n)
+{
+	if (n < INT_MIN)
+		return scalbn(x, INT_MIN);
+	else if (n > INT_MAX)
+		return scalbn(x, INT_MAX);
+	else
+		return scalbn(x, (int)n);
+}
+
+long double
+scalblnl(long double x, long n)
+{
+	if (n < INT_MIN)
+		return scalbnl(x, INT_MIN);
+	else if (n > INT_MAX)
+		return scalbnl(x, INT_MAX);
+	else
+		return scalbnl(x, (int)n);
+}
+