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, 50 insertions, 0 deletions

diff --git a/usr/src/lib/libm/common/C/significand.c b/usr/src/lib/libm/common/C/significand.c
new file mode 100644
index 0000000000..4f2e3f95a6
--- /dev/null
+++ b/usr/src/lib/libm/common/C/significand.c
@@ -0,0 +1,50 @@
+/*
+ * 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 significand = __significand
+#endif
+
+#include "libm.h"
+
+double
+significand(double x) {
+	int ix = ((int *) &x)[HIWORD] & ~0x80000000;
+
+	/* weed out 0/+-Inf/NaN because C99 ilogb raises invalid on them */
+	if ((ix | ((int *) &x)[LOWORD]) == 0 || ix >= 0x7ff00000)
+#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
+		return ((ix & 0x80000) != 0 ? x : x + x);
+		/* assumes sparc-like QNaN */
+#else
+		return (x + x);
+#endif
+	else
+		return (scalbn(x, -ilogb(x)));
+}