1 files changed, 87 insertions, 0 deletions
diff --git a/usr/src/lib/libm/common/Q/ilogbl.c b/usr/src/lib/libm/common/Q/ilogbl.c
new file mode 100644
index 0000000000..bdbe2dbd0f
--- /dev/null
+++ b/usr/src/lib/libm/common/Q/ilogbl.c
@@ -0,0 +1,87 @@
+/*
+ * 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 ilogbl = __ilogbl
+#endif
+
+#include "libm.h"
+#include "xpg6.h"	/* __xpg6 */
+
+#if defined(__sparc)
+#define	ISNORMALL(k, x)	(k != 0x7fff)			/* assuming k != 0 */
+#define	X86PDNRM(k, x)
+#define	XSCALE_OFFSET	0x406f				/* 0x3fff + 112 */
+static const long double xscale = 5192296858534827628530496329220096.0L;
+								/* 2^112 */
+#elif defined(__x86)
+/*
+ * if pseudo-denormal, replace by the equivalent normal
+ */
+#define	X86PDNRM(k, x)	if (k == 0 && (((int *) &x)[1] & 0x80000000) != 0) \
+				((int *) &x)[2] |= k = 1
+#if defined(HANDLE_UNSUPPORTED)				/* assuming k != 0 */
+#define	ISNORMALL(k, x)	(k != 0x7fff && (((int *) &x)[1] & 0x80000000) != 0)
+#else
+#define	ISNORMALL(k, x)	(k != 0x7fff)
+#endif
+#define	XSCALE_OFFSET	0x403e				/* 0x3fff + 63 */
+static const long double xscale = 9223372036854775808.0L;	/* 2^63 */
+#endif
+
+static int
+raise_invalid(int v) {	/* SUSv3 requires ilogbl(0,+/-Inf,NaN) raise invalid */
+#ifndef lint
+	if ((__xpg6 & _C99SUSv3_ilogb_0InfNaN_raises_invalid) != 0) {
+		static const double zero = 0.0;
+		volatile double dummy;
+
+		dummy = zero / zero;
+	}
+#endif
+	return (v);
+}
+
+int
+ilogbl(long double x) {
+	int k = XBIASED_EXP(x);
+
+	X86PDNRM(k, x);
+	if (k == 0) {
+		if (ISZEROL(x))
+			return (raise_invalid(0x80000001));
+		else {
+			x *= xscale;		/* scale up by 2^112 or 2^63 */
+			return (XBIASED_EXP(x) - XSCALE_OFFSET);
+		}
+	} else if (ISNORMALL(k, x))
+		return (k - 0x3fff);
+	else
+		return (raise_invalid(0x7fffffff));
+}