Optimize use of isnan, isinf, finite

1 files changed, 19 insertions, 0 deletions

diff --git a/sysdeps/ieee754/ldbl-128/s_isinf_nsl.c b/sysdeps/ieee754/ldbl-128/s_isinf_nsl.c
new file mode 100644
index 0000000000..1ebc1accbc
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_isinf_nsl.c
@@ -0,0 +1,19 @@
+/*
+ * Written by Ulrich Drepper <drepper@gmail.com>
+ */
+
+/*
+ * __isinf_nsl(x) returns != 0 if x is ±inf, else 0;
+ * no branching!
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+int
+__isinf_nsl (long double x)
+{
+	int64_t hx,lx;
+	GET_LDOUBLE_WORDS64(hx,lx,x);
+	return !(lx | ((hx & 0x7fffffffffffffffLL) ^ 0x7fff000000000000LL));
+}