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 __sinhl = sinhl 31 32 #include "libm.h" 33 #include "longdouble.h" 34 35 /* SINH(X) 36 * RETURN THE HYPERBOLIC SINE OF X 37 * 38 * Method : 39 * 1. reduce x to non-negative by SINH(-x) = - SINH(x). 40 * 2. 41 * 42 * EXPM1(x) + EXPM1(x)/(EXPM1(x)+1) 43 * 0 <= x <= lnovft : SINH(x) := -------------------------------- 44 * 2 45 * 46 * lnovft <= x < INF : SINH(x) := EXP(x-MEP1*ln2)*2**ME 47 * 48 * here 49 * lnovft logarithm of the overflow threshold 50 * = MEP1*ln2 chopped to machine precision. 51 * ME maximum exponent 52 * MEP1 maximum exponent plus 1 53 * 54 * Special cases: 55 * SINH(x) is x if x is +INF, -INF, or NaN. 56 * only SINH(0)=0 is exact for finite argument. 57 * 58 */ 59 60 static const long double C[] = { 61 0.5L, 62 1.0L, 63 1.135652340629414394879149e+04L, 64 7.004447686242549087858985e-16L 65 }; 66 67 #define half C[0] 68 #define one C[1] 69 #define lnovft C[2] 70 #define lnovlo C[3] 71 72 long double 73 sinhl(long double x) 74 { 75 long double r, t; 76 77 if (!finitel(x)) 78 return (x + x); /* x is INF or NaN */ 79 r = fabsl(x); 80 if (r < lnovft) { 81 t = expm1l(r); 82 r = copysignl((t + t / (one + t)) * half, x); 83 } else { 84 r = copysignl(expl((r - lnovft) - lnovlo), x); 85 r = scalbnl(r, 16383); 86 } 87 return (r); 88 } 89