--- /dev/null
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double complex cacosl(long double complex z)
+{
+ return cacos(z);
+}
+#else
+// FIXME
+#define PI_2 1.57079632679489661923132169163975144L
+long double complex cacosl(long double complex z)
+{
+ z = casinl(z);
+ return cpackl(PI_2 - creall(z), -cimagl(z));
+}
+#endif