1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24 */ 25 /* 26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 #pragma weak __acoshl = acoshl 31 32 #include "libm.h" 33 34 static const long double 35 zero = 0.0L, 36 ln2 = 6.931471805599453094172321214581765680755e-0001L, 37 one = 1.0L, 38 big = 1.e+20L; 39 40 long double 41 acoshl(long double x) { 42 long double t; 43 44 if (isnanl(x)) 45 return (x + x); 46 else if (x > big) 47 return (logl(x) + ln2); 48 else if (x > one) { 49 t = sqrtl(x - one); 50 return (log1pl(t * (t + sqrtl(x + one)))); 51 } else if (x == one) 52 return (zero); 53 else 54 return ((x - x) / (x - x)); 55 } 56