1 files changed, 41 insertions, 0 deletions
diff --git a/winsup/mingw/mingwex/complex/ctanf.c b/winsup/mingw/mingwex/complex/ctanf.c
new file mode 100755
index 000000000..99699e427
--- /dev/null
+++ b/winsup/mingw/mingwex/complex/ctanf.c
@@ -0,0 +1,41 @@
+/* ctanf.c */
+
+/*
+   Contributed by Danny Smith
+   2004-12-24
+*/
+
+#include <math.h>
+#include <complex.h>
+#include <errno.h>
+
+
+/* ctan (x + I * y) = (sin (2 * x)  +  I * sinh(2 * y))
+		      / (cos (2 * x)  +  cosh (2 * y)) */
+
+float complex ctanf (float complex Z)
+{
+  float complex Res;
+  float two_I = 2.0f * __imag__ Z;
+  float two_R = 2.0f * __real__ Z;
+  float denom = cosf (two_R) + coshf (two_I);
+  if (denom == 0.0f)
+    {
+      errno = ERANGE;
+      __real__ Res = HUGE_VALF;
+      __imag__ Res = HUGE_VALF;
+    }
+  else if (isinf (denom))
+    {
+      errno = ERANGE;
+      __real__ Res = 0.0;
+      __imag__ Res = two_I > 0 ? 1.0f : -1.0f;
+    }
+  else
+    {
+      __real__ Res = sinf (two_R) / denom;
+      __imag__ Res = sinhf (two_I) / denom;
+    }
+  return Res;
+}
+