1 files changed, 30 insertions, 0 deletions
diff --git a/lib/libm/src/s_isinff.c b/lib/libm/src/s_isinff.c
new file mode 100644
index 00000000000..4ff94269740
--- /dev/null
+++ b/lib/libm/src/s_isinff.c
@@ -0,0 +1,30 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: s_isinff.c,v 1.3 1995/05/11 23:20:21 jtc Exp $";
+#endif
+
+/*
+ * isinff(x) returns 1 is x is inf, else 0;
+ * no branching!
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+	int isinff(float x)
+#else
+	int isinff(x)
+	float x;
+#endif
+{
+	int32_t ix;
+	GET_FLOAT_WORD(ix,x);
+	ix &= 0x7fffffff;
+	ix ^= 0x7f800000;
+	return (ix == 0);
+}