lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 137 insertions, 0 deletions

diff --git a/lib/mlibc/options/ansi/generic/complex/csqrt.c b/lib/mlibc/options/ansi/generic/complex/csqrt.c
new file mode 100644
index 0000000..b144b7c
--- /dev/null
+++ b/lib/mlibc/options/ansi/generic/complex/csqrt.c
@@ -0,0 +1,137 @@
+/* $NetBSD: csqrt.c,v 1.1 2007/08/20 16:01:37 drochner 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.
+ *
+ * imported and modified include for newlib 2010/10/03 
+ * Marco Atzeri <marco_atzeri@yahoo.it>
+ */
+
+/*
+FUNCTION
+        <<csqrt>>, <<csqrtf>>---complex square root
+
+INDEX
+        csqrt
+INDEX
+        csqrtf
+
+ANSI_SYNOPSIS
+       #include <complex.h>
+       double complex csqrt(double complex <[z]>);
+       float complex csqrtf(float complex <[z]>);
+
+
+DESCRIPTION
+        These functions compute the complex square root of <[z]>, with 
+        a branch cut along the negative real axis. 
+
+        <<csqrtf>> is identical to <<csqrt>>, except that it performs
+        its calculations on <<floats complex>>.
+
+RETURNS
+        The csqrt functions return the complex square root value, in 
+        the range of the right halfplane (including the imaginary axis).
+
+PORTABILITY
+        <<csqrt>> and <<csqrtf>> are ISO C99
+
+QUICKREF
+        <<csqrt>> and <<csqrtf>> are ISO C99
+
+*/
+
+
+#include <complex.h>
+#include <math.h>
+
+double complex
+csqrt(double complex z)
+{
+	double complex w;
+	double x, y, r, t, scale;
+
+	x = creal (z);
+	y = cimag (z);
+
+	if (y == 0.0) {
+		if (x == 0.0) {
+			w = 0.0 + y * I;
+		} else {
+			r = fabs(x);
+			r = sqrt(r);
+			if (x < 0.0) {
+				w = 0.0 + r * I;
+			} else {
+				w = r + y * I;
+			}
+		}
+		return w;
+	}
+	if (x == 0.0) {
+		r = fabs(y);
+		r = sqrt(0.5 * r);
+		if (y > 0)
+			w = r + r * I;
+		else
+			w = r - r * I;
+		return w;
+	}
+	/* Rescale to avoid internal overflow or underflow.  */
+	if ((fabs(x) > 4.0) || (fabs(y) > 4.0)) {
+		x *= 0.25;
+		y *= 0.25;
+		scale = 2.0;
+	} else {
+#if 1
+		x *= 1.8014398509481984e16;  /* 2^54 */
+		y *= 1.8014398509481984e16;
+		scale = 7.450580596923828125e-9; /* 2^-27 */
+#else
+		x *= 4.0;
+		y *= 4.0;
+		scale = 0.5;
+#endif
+	}
+	w = x + y * I;
+	r = cabs(w);
+	if (x > 0) {
+		t = sqrt(0.5 * r + 0.5 * x);
+		r = scale * fabs((0.5 * y) / t );
+		t *= scale;
+	} else {
+		r = sqrt(0.5 * r - 0.5 * x);
+		t = scale * fabs((0.5 * y) / r);
+		r *= scale;
+	}
+	if (y < 0)
+		w = t - r * I;
+	else
+		w = t + r * I;
+	return w;
+}