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 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 23 */ 24 /* 25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 29 #pragma weak __sinh = sinh 30 31 /* INDENT OFF */ 32 /* 33 * sinh(x) 34 * Code originated from 4.3bsd. 35 * Modified by K.C. Ng for SUN 4.0 libm. 36 * Method : 37 * 1. reduce x to non-negative by sinh(-x) = - sinh(x). 38 * 2. 39 * 40 * expm1(x) + expm1(x)/(expm1(x)+1) 41 * 0 <= x <= lnovft : sinh(x) := -------------------------------- 42 * 2 43 * lnovft <= x < INF : sinh(x) := exp(x-1024*ln2)*2**1023 44 * 45 * 46 * Special cases: 47 * sinh(x) is x if x is +INF, -INF, or NaN. 48 * only sinh(0)=0 is exact for finite argument. 49 * 50 */ 51 /* INDENT ON */ 52 53 #include "libm.h" 54 55 static const double 56 ln2hi = 6.93147180369123816490e-01, 57 ln2lo = 1.90821492927058770002e-10, 58 lnovft = 7.09782712893383973096e+02; 59 60 double 61 sinh(double x) { 62 double ox, r, t; 63 64 ox = x; 65 r = fabs(x); 66 if (!finite(x)) 67 return (x * r); 68 if (r < lnovft) { 69 t = expm1(r); 70 r = copysign((t + t / (1.0 + t)) * 0.5, x); 71 } else { 72 if (r < 1000.0) 73 x = copysign(exp((r - 1024 * ln2hi) - 1024 * ln2lo), x); 74 r = scalbn(x, 1023); 75 } 76 if (!finite(r)) 77 r = _SVID_libm_err(ox, ox, 25); 78 return (r); 79 } 80