about summary refs log tree commit diff
path: root/sysdeps/ieee754/flt-32/s_isinff.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ieee754/flt-32/s_isinff.c')
-rw-r--r--sysdeps/ieee754/flt-32/s_isinff.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/sysdeps/ieee754/flt-32/s_isinff.c b/sysdeps/ieee754/flt-32/s_isinff.c
new file mode 100644
index 0000000000..efc0935251
--- /dev/null
+++ b/sysdeps/ieee754/flt-32/s_isinff.c
@@ -0,0 +1,28 @@
+/*
+ * 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 if x is inf, -1 if x is -inf, else 0;
+ * no branching!
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+int
+__isinff (float x)
+{
+	int32_t ix,t;
+	GET_FLOAT_WORD(ix,x);
+	t = ix & 0x7fffffff;
+	t ^= 0x7f800000;
+	t |= -t;
+	return ~(t >> 31) & (ix >> 30);
+}
+weak_alias (__isinff, isinff)