1 files changed, 50 insertions, 0 deletions
diff --git a/contrib/libf2c/libF77/pow_zi.c b/contrib/libf2c/libF77/pow_zi.c
new file mode 100644
index 0000000..214db3d
--- /dev/null
+++ b/contrib/libf2c/libF77/pow_zi.c
@@ -0,0 +1,50 @@
+#include "f2c.h"
+
+extern void z_div (doublecomplex *, doublecomplex *, doublecomplex *);
+void
+pow_zi (doublecomplex * p, doublecomplex * a, integer * b)	/* p = a**b  */
+{
+  integer n;
+  unsigned long u;
+  double t;
+  doublecomplex q, x;
+  static doublecomplex one = { 1.0, 0.0 };
+
+  n = *b;
+  q.r = 1;
+  q.i = 0;
+
+  if (n == 0)
+    goto done;
+  if (n < 0)
+    {
+      n = -n;
+      z_div (&x, &one, a);
+    }
+  else
+    {
+      x.r = a->r;
+      x.i = a->i;
+    }
+
+  for (u = n;;)
+    {
+      if (u & 01)
+	{
+	  t = q.r * x.r - q.i * x.i;
+	  q.i = q.r * x.i + q.i * x.r;
+	  q.r = t;
+	}
+      if (u >>= 1)
+	{
+	  t = x.r * x.r - x.i * x.i;
+	  x.i = 2 * x.r * x.i;
+	  x.r = t;
+	}
+      else
+	break;
+    }
+done:
+  p->i = q.i;
+  p->r = q.r;
+}