[newlib-cygwin] Importing casinl.c from NetBSD.

[newlib-cygwin] Importing casinl.c from NetBSD.

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=a168d244c6e76f92b7f9d3ffd4335b0d71691f55

commit a168d244c6e76f92b7f9d3ffd4335b0d71691f55
Author: Aditya Upadhyay <aadit0402@gmail.com>
Date:   Thu Jun 29 01:38:01 2017 +0530

    Importing casinl.c from NetBSD.

Diff:
---
 newlib/libm/complex/Makefile.am |   2 +-
 newlib/libm/complex/casinl.c    | 120 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 121 insertions(+), 1 deletion(-)

diff --git a/newlib/libm/complex/Makefile.am b/newlib/libm/complex/Makefile.am
index ff651eb..3af9f65 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
+       cephes_subrl.c cacosl.c ccosl.c casinl.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/casinl.c b/newlib/libm/complex/casinl.c
new file mode 100755
index 0000000..4884889
--- /dev/null
+++ b/newlib/libm/complex/casinl.c
@@ -0,0 +1,120 @@
+/* $NetBSD: casinl.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>
+
+#ifdef __weak_alias
+__weak_alias(casinl, _casinl)
+#endif
+
+long double complex
+casinl(long double complex z)
+{
+	long double complex w;
+	long double complex ca, ct, zz, z2;
+	long double x, y;
+
+	x = creall(z);
+	y = cimagl(z);
+
+#if 0 /* MD: test is incorrect, casin(>1) is defined */
+	if (y == 0.0L) {
+		if (fabsl(x) > 1.0L) {
+			w = M_PI_2L + 0.0L * I;
+#if 0
+			mtherr ("casinl", DOMAIN);
+#endif
+		} else {
+			w = asinl(x) + 0.0L * I;
+		}
+		return w;
+	}
+#endif
+
+/* Power series expansion */
+/*
+b = cabsl(z);
+if( b < 0.125L )
+{
+z2.r = (x - y) * (x + y);
+z2.i = 2.0L * x * y;
+
+cn = 1.0L;
+n = 1.0L;
+ca.r = x;
+ca.i = y;
+sum.r = x;
+sum.i = y;
+do
+	{
+	ct.r = z2.r * ca.r  -  z2.i * ca.i;
+	ct.i = z2.r * ca.i  +  z2.i * ca.r;
+	ca.r = ct.r;
+	ca.i = ct.i;
+
+	cn *= n;
+	n += 1.0;
+	cn /= n;
+	n += 1.0;
+	b = cn/n;
+
+	ct.r *= b;
+	ct.i *= b;
+	sum.r += ct.r;
+	sum.i += ct.i;
+	b = fabsl(ct.r) + fabsl(ct.i);
+	}
+while( b > MACHEPL );
+w->r = sum.r;
+w->i = sum.i;
+return;
+}
+*/
+
+
+	ca = x + y * I;
+	ct = ca * I;
+	/* sqrtl( 1 - z*z) */
+	/* cmull( &ca, &ca, &zz ) */
+	/*x * x  -  y * y */
+	zz = (x - y) * (x + y) + (2.0L * x * y) * I;
+
+	zz = 1.0L - creall(zz) - cimagl(zz) * I;
+	z2 = csqrtl(zz);
+
+	zz = ct + z2;
+	zz = clogl(zz);
+	/* multiply by 1/i = -i */
+	w = zz * (-1.0L * I);
+	return w;
+}
+