Porting cpowl.c from NetBSD

[Aditya Upadhyay <aadit0402 at gmail dot com>]

Hello Developers,

This is the patch for cpowl.c ported from NetBSD. I am requesting you
to please review the same and suggest the changes.

Thanks & Regards,
Aditya Upadhyay

From d9a3395eda6b3dc842cbcebfd731ad0a324d2f3b Mon Sep 17 00:00:00 2001
From: Aditya Upadhyay <aadit0402@gmail.com>
Date: Wed, 28 Jun 2017 18:29:10 +0530
Subject: [PATCH 10/10] Importing cpowl.c from NetBSD.

---
 newlib/libm/complex/Makefile.am |  2 +-
 newlib/libm/complex/cpowl.c     | 56 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 newlib/libm/complex/cpowl.c

diff --git a/newlib/libm/complex/Makefile.am b/newlib/libm/complex/Makefile.am
index de2fca9..e121ac5 100644
--- a/newlib/libm/complex/Makefile.am
+++ b/newlib/libm/complex/Makefile.am
@@ -12,7 +12,7 @@ src = cabs.c cacos.c cacosh.c carg.c casin.c casinh.c \
 
 lsrc = cabsl.c creall.c cimagl.c ccoshl.c cacoshl.c \ 
        clogl.c csqrtl.c cargl.c cprojl.c cexpl.c cephes_subrl.c\
-       cacosl.c ccosl.c
+       cacosl.c ccosl.c cpowl.c
 
 fsrc =	cabsf.c casinf.c ccosf.c cimagf.c cprojf.c  \
         csqrtf.c cacosf.c casinhf.c ccoshf.c clogf.c clog10f.c \
diff --git a/newlib/libm/complex/cpowl.c b/newlib/libm/complex/cpowl.c
new file mode 100644
index 0000000..85c2c20
--- /dev/null
+++ b/newlib/libm/complex/cpowl.c
@@ -0,0 +1,56 @@
+/* $NetBSD: cpowl.c,v 1.1 2014/10/10 00:48:18 christos Exp $ */
+
+/*-
+ * Copyright (c) 2007 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software written by Stephen L. Moshier.
+ * It is redistributed by the NetBSD Foundation by permission of the author.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <complex.h>
+#include <math.h>
+
+long double complex
+cpowl(long double complex a, long double complex z)
+{
+	long double complex w;
+	long double x, y, r, theta, absa, arga;
+
+	x = creall(z);
+	y = cimagl(z);
+	absa = cabsl(a);
+	if (absa == 0.0L) {
+		return (0.0L + 0.0L * I);
+	}
+	arga = cargl(a);
+	r = powl(absa, x);
+	theta = x * arga;
+	if (y != 0.0L) {
+		r = r * expl(-y * arga);
+		theta = theta + y * logl(absa);
+	}
+	w = r * cosl(theta) + (r * sinl(theta)) * I;
+	return w;
+}
-- 
2.7.4