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, 65 insertions, 0 deletions

diff --git a/usr/src/lib/libm/common/C/floor.c b/usr/src/lib/libm/common/C/floor.c
new file mode 100644
index 0000000000..6c3a612c21
--- /dev/null
+++ b/usr/src/lib/libm/common/C/floor.c
@@ -0,0 +1,65 @@
+/*
+ * 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 floor = __floor
+
+/*
+ * floor(x) returns the biggest integral value less than or equal to x.
+ * NOTE: floor(x) returns result with the same sign as x's, including 0.
+ *
+ * Modified 8/4/04 for performance.
+ */
+
+#include "libm.h"
+
+static const double
+	zero = 0.0,
+	one = 1.0,
+	two52 = 4503599627370496.0;
+
+double
+floor(double x) {
+	double	t, w;
+	int	hx, lx, ix;
+
+	hx = ((int *)&x)[HIWORD];
+	lx = ((int *)&x)[LOWORD];
+	ix = hx & ~0x80000000;
+	if (ix >= 0x43300000)	/* return x if |x| >= 2^52, or x is NaN */
+		return (x * one);
+	t = (hx >= 0)? two52 : -two52;
+	w = x + t;
+	t = w - t;
+	if (ix < 0x3ff00000) {
+		if ((ix | lx) == 0)
+			return (x);
+		else
+			return ((hx < 0)? -one : zero);
+	}
+	return ((t <= x)? t : t - one);
+}