1 files changed, 55 insertions, 0 deletions
diff --git a/winsup/mingw/mingwex/complex/csqrt.c b/winsup/mingw/mingwex/complex/csqrt.c
new file mode 100644
index 000000000..3717939f4
--- /dev/null
+++ b/winsup/mingw/mingwex/complex/csqrt.c
@@ -0,0 +1,55 @@
+/*
+   csqrt.c
+   Contributed by Danny Smith
+   2003-10-20
+*/
+
+#include <math.h>
+#include <complex.h>
+
+double complex  csqrt (double complex Z)
+{
+  double complex Res;
+  double t;
+  double x = __real__ Z;
+  double y = __imag__ Z;
+
+  if (y == 0.0)
+    {
+      if (x < 0.0)
+        {
+ 	  __real__ Res = 0.0;
+	  __imag__ Res = sqrt (-x);
+        }
+      else
+        {
+ 	  __real__ Res = sqrt (x);
+	  __imag__ Res = 0.0;
+        }
+    }
+
+  else if (x == 0.0)
+    {
+      t = sqrt(0.5 * fabs (y));
+      __real__ Res = y > 0 ? t : -t;
+      __imag__ Res = t;
+    }
+
+  else
+    {
+      t = sqrt (2.0  * (_hypot (x, y) + fabs (x)));
+      if ( x > 0.0)
+        {	
+          __real__ Res = 0.5 * t;
+          __imag__ Res = y / t;
+        }
+      else
+        {
+	  __real__ Res = fabs ( y / t);
+	  __imag__ Res = (y < 0.0 ? -0.5 : 0.5) * t;
+        }
+    }
+
+  return Res;
+}
+