125c28e83SPiotr Jasiukajtis /*
225c28e83SPiotr Jasiukajtis * CDDL HEADER START
325c28e83SPiotr Jasiukajtis *
425c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the
525c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License").
625c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License.
725c28e83SPiotr Jasiukajtis *
825c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
925c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing.
1025c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions
1125c28e83SPiotr Jasiukajtis * and limitations under the License.
1225c28e83SPiotr Jasiukajtis *
1325c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each
1425c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
1525c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the
1625c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying
1725c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner]
1825c28e83SPiotr Jasiukajtis *
1925c28e83SPiotr Jasiukajtis * CDDL HEADER END
2025c28e83SPiotr Jasiukajtis */
2125c28e83SPiotr Jasiukajtis
2225c28e83SPiotr Jasiukajtis /*
2325c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
2425c28e83SPiotr Jasiukajtis */
2525c28e83SPiotr Jasiukajtis /*
2625c28e83SPiotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
2725c28e83SPiotr Jasiukajtis * Use is subject to license terms.
2825c28e83SPiotr Jasiukajtis */
2925c28e83SPiotr Jasiukajtis
30*ddc0e0b5SRichard Lowe #pragma weak __logbl = logbl
3125c28e83SPiotr Jasiukajtis
3225c28e83SPiotr Jasiukajtis #include "libm.h"
3325c28e83SPiotr Jasiukajtis #include "xpg6.h" /* __xpg6 */
3425c28e83SPiotr Jasiukajtis #define _C99SUSv3_logb _C99SUSv3_logb_subnormal_is_like_ilogb
3525c28e83SPiotr Jasiukajtis
3625c28e83SPiotr Jasiukajtis #if defined(__sparc)
3725c28e83SPiotr Jasiukajtis #define ISNORMALL(k, x) (k != 0x7fff) /* assuming k != 0 */
3825c28e83SPiotr Jasiukajtis #define X86PDNRM(k, x)
3925c28e83SPiotr Jasiukajtis #define XSCALE_OFFSET 0x406f /* 0x3fff + 112 */
4025c28e83SPiotr Jasiukajtis static const long double xscale = 5192296858534827628530496329220096.0L;
4125c28e83SPiotr Jasiukajtis /* 2^112 */
4225c28e83SPiotr Jasiukajtis #elif defined(__x86)
4325c28e83SPiotr Jasiukajtis /*
4425c28e83SPiotr Jasiukajtis * if pseudo-denormal, replace by the equivalent normal
4525c28e83SPiotr Jasiukajtis */
4625c28e83SPiotr Jasiukajtis #define X86PDNRM(k, x) if (k == 0 && (((int *) &x)[1] & 0x80000000) != 0) \
4725c28e83SPiotr Jasiukajtis ((int *) &x)[2] |= k = 1
4825c28e83SPiotr Jasiukajtis #if defined(HANDLE_UNSUPPORTED) /* assuming k != 0 */
4925c28e83SPiotr Jasiukajtis #define ISNORMALL(k, x) (k != 0x7fff && (((int *) &x)[1] & 0x80000000) != 0)
5025c28e83SPiotr Jasiukajtis #else
5125c28e83SPiotr Jasiukajtis #define ISNORMALL(k, x) (k != 0x7fff)
5225c28e83SPiotr Jasiukajtis #endif
5325c28e83SPiotr Jasiukajtis #define XSCALE_OFFSET 0x403e /* 0x3fff + 63 */
5425c28e83SPiotr Jasiukajtis static const long double xscale = 9223372036854775808.0L; /* 2^63 */
5525c28e83SPiotr Jasiukajtis #endif
5625c28e83SPiotr Jasiukajtis
5725c28e83SPiotr Jasiukajtis static long double
raise_division(long double v)5825c28e83SPiotr Jasiukajtis raise_division(long double v) {
5925c28e83SPiotr Jasiukajtis #pragma STDC FENV_ACCESS ON
6025c28e83SPiotr Jasiukajtis static const long double zero = 0.0L;
6125c28e83SPiotr Jasiukajtis return (v / zero);
6225c28e83SPiotr Jasiukajtis }
6325c28e83SPiotr Jasiukajtis
6425c28e83SPiotr Jasiukajtis long double
logbl(long double x)6525c28e83SPiotr Jasiukajtis logbl(long double x) {
6625c28e83SPiotr Jasiukajtis int k = XBIASED_EXP(x);
6725c28e83SPiotr Jasiukajtis
6825c28e83SPiotr Jasiukajtis X86PDNRM(k, x);
6925c28e83SPiotr Jasiukajtis if (k == 0) {
7025c28e83SPiotr Jasiukajtis if (ISZEROL(x))
7125c28e83SPiotr Jasiukajtis return (raise_division(-1.0L));
7225c28e83SPiotr Jasiukajtis else if ((__xpg6 & _C99SUSv3_logb) != 0) {
7325c28e83SPiotr Jasiukajtis x *= xscale; /* scale up by 2^112 or 2^63 */
7425c28e83SPiotr Jasiukajtis return (long double) (XBIASED_EXP(x) - XSCALE_OFFSET);
7525c28e83SPiotr Jasiukajtis } else
7625c28e83SPiotr Jasiukajtis return (-16382.L);
7725c28e83SPiotr Jasiukajtis } else if (ISNORMALL(k, x))
7825c28e83SPiotr Jasiukajtis return ((long double) (k - 0x3fff));
7925c28e83SPiotr Jasiukajtis else
8025c28e83SPiotr Jasiukajtis return (x * x);
8125c28e83SPiotr Jasiukajtis }
82