1 files changed, 34 insertions, 0 deletions
diff --git a/lib/libm/catanl.c b/lib/libm/catanl.c
new file mode 100644
index 00000000..949dc3d9
--- /dev/null
+++ b/lib/libm/catanl.c
@@ -0,0 +1,34 @@
+#include <float.h>
+#include "__complex.h"
+
+long double complex catanl(long double complex z)
+{
+	long double complex w;
+	long double a, t, x, x2, y;
+
+	x = creall(z);
+	y = cimagl(z);
+
+	if ((x == 0.0L) && (y > 1.0L))
+		goto overflow;
+
+	x2 = x * x;
+	a = 1.0L - x2 - (y * y);
+	if (a == 0.0)
+		goto overflow;
+
+	t = 0.5L * atan2l(2.0L * x, a);
+	w = redupil(t);
+
+	t = y - 1.0L;
+	a = x2 + (t * t);
+	if (a == 0.0L)
+		goto overflow;
+
+	t = y + 1.0L;
+	a = (x2 + (t * t)) / a;
+	return w + (0.25L * logl(a)) * I;
+
+overflow:
+	return LDBL_MAX + LDBL_MAX * I;
+}