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, 73 insertions, 0 deletions

diff --git a/usr/src/lib/libm/common/C/scalb.c b/usr/src/lib/libm/common/C/scalb.c
new file mode 100644
index 0000000000..ea5555266a
--- /dev/null
+++ b/usr/src/lib/libm/common/C/scalb.c
@@ -0,0 +1,73 @@
+/*
+ * 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 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma weak scalb = __scalb
+#pragma weak _scalb = __scalb
+
+#include "libm.h"
+
+double
+scalb(double x, double fn) {
+	int	hn, in, n;
+	double	z;
+
+	if (isnan(x) || isnan(fn))
+		return (x * fn);
+
+	in = ((int *)&fn)[HIWORD];
+	hn = in & ~0x80000000;
+	if (hn == 0x7ff00000)	/* fn is inf */
+		return (_SVID_libm_err(x, fn, 47));
+
+	/* see if fn is an integer without raising inexact */
+	if (hn >= 0x43300000) {
+		/* |fn| >= 2^52, so it must be an integer */
+		n = (in < 0)? -65000 : 65000;
+	} else if (hn < 0x3ff00000) {
+		/* |fn| < 1, so it must be zero or non-integer */
+		return ((fn == 0.0)? x : (x - x) / (x - x));
+	} else if (hn < 0x41400000) {
+		/* |fn| < 2^21 */
+		if ((hn & ((1 << (0x413 - (hn >> 20))) - 1))
+		    | ((int *)&fn)[LOWORD])
+			return ((x - x) / (x - x));
+		n = (int)fn;
+	} else {
+		if (((int *)&fn)[LOWORD] & ((1 << (0x433 - (hn >> 20))) - 1))
+			return ((x - x) / (x - x));
+		n = (in < 0)? -65000 : 65000;
+	}
+	z = scalbn(x, n);
+	if (z != x) {
+		if (z == 0.0)
+			return (_SVID_libm_err(x, fn, 33));
+		if (!finite(z))
+			return (_SVID_libm_err(x, fn, 32));
+	}
+	return (z);
+}