Optimize use of isnan, isinf, finite

1 files changed, 20 insertions, 0 deletions

diff --git a/sysdeps/ieee754/flt-32/s_isinf_nsf.c b/sysdeps/ieee754/flt-32/s_isinf_nsf.c
new file mode 100644
index 0000000000..bc37785168
--- /dev/null
+++ b/sysdeps/ieee754/flt-32/s_isinf_nsf.c
@@ -0,0 +1,20 @@
+/*
+ * Written by Ulrich Drepper <drepper@gmail.com>.
+ */
+
+/*
+ * __isinf_nsf(x) returns != 0 if x is ±inf, else 0;
+ * no branching!
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#undef __isinf_nsf
+int
+__isinf_nsf (float x)
+{
+	int32_t ix,t;
+	GET_FLOAT_WORD(ix,x);
+	return (ix & 0x7fffffff) == 0x7f800000;
+}