1 files changed, 48 insertions, 0 deletions
diff --git a/winsup/mingw/mingwex/complex/cpow.c b/winsup/mingw/mingwex/complex/cpow.c
new file mode 100644
index 000000000..c12b12fc0
--- /dev/null
+++ b/winsup/mingw/mingwex/complex/cpow.c
@@ -0,0 +1,48 @@
+/*  cpow.c */
+/*
+   Contributed by Danny Smith
+   2003-10-20
+*/
+
+/* cpow(X, Y) = cexp(X * clog(Y)) */
+
+#include <math.h>
+#include <complex.h>
+
+/* Use dll version of pow */
+extern double  (*_imp__pow) (double, double);
+#define pow (*_imp__pow)
+
+double complex cpow (double complex X, double complex Y)
+{
+  double complex Res;
+  double i;
+  double r = hypot (__real__ X, __imag__ X);
+  if (r == 0.0)
+    {
+       __real__ Res = __imag__ Res = 0.0;
+    }
+  else
+    {
+      double rho;
+      double theta;
+      i = carg (X);
+      theta = i * __real__ Y;
+ 
+      if (__imag__ Y == 0.0)
+	/* This gives slightly more accurate results in these cases. */
+   	rho = pow (r, __real__ Y);
+      else
+	{
+          r = log (r);
+	  /* rearrangement of cexp(X * clog(Y)) */
+	  theta += r * __imag__ Y;
+	  rho = exp (r * __real__ Y - i * __imag__ Y);
+	}
+
+      __real__ Res = rho * cos (theta);
+      __imag__ Res = rho * sin (theta);
+    }
+  return  Res;
+}
+