693 Opensource replacement of sunwlibm

Reviewed by: Igor Kozhukhov ikozhukhov@gmail.com
Reviewed by: Keith M Wesolowski <keith.wesolowski@joyent.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Dan McDonald <danmcd@omniti.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/usr/src/lib/libm/common/Q/asinl.c b/usr/src/lib/libm/common/Q/asinl.c
new file mode 100644
index 0000000000..8594a2195b
--- /dev/null
+++ b/usr/src/lib/libm/common/Q/asinl.c
@@ -0,0 +1,78 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#if defined(ELFOBJ)
+#pragma weak asinl = __asinl
+#endif
+
+/*
+ *	asinl(x) = atan2l(x,sqrt(1-x*x));
+ *
+ * For better accuracy, 1-x*x is computed as follows
+ *	1-x*x                     if x <  0.5,
+ *	2*(1-|x|)-(1-|x|)*(1-|x|) if x >= 0.5.
+ *
+ * Special cases:
+ *	if x is NaN, return x itself;
+ *	if |x|>1, return NaN with invalid signal.
+ */
+
+#include "libm.h"
+
+static const long double zero = 0.0L, small = 1.0e-20L, half = 0.5L, one = 1.0L;
+#ifndef lint
+static const long double big = 1.0e+20L;
+#endif
+
+long double
+asinl(long double x) {
+	long double t, w;
+	volatile long double dummy;
+
+	w = fabsl(x);
+	if (isnanl(x))
+		return (x + x);
+	else if (w <= half) {
+		if (w < small) {
+#ifndef lint
+			dummy = w + big;
+							/* inexact if w != 0 */
+#endif
+			return (x);
+		} else
+			return (atanl(x / sqrtl(one - x * x)));
+	} else if (w < one) {
+		t = one - w;
+		w = t + t;
+		return (atanl(x / sqrtl(w - t * t)));
+	} else if (w == one)
+		return (atan2l(x, zero));	/* asin(+-1) =  +- PI/2 */
+	else
+		return (zero / zero);		/* |x| > 1: invalid */
+}