1*25c28e83SPiotr Jasiukajtis /* 2*25c28e83SPiotr Jasiukajtis * CDDL HEADER START 3*25c28e83SPiotr Jasiukajtis * 4*25c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the 5*25c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License"). 6*25c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License. 7*25c28e83SPiotr Jasiukajtis * 8*25c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9*25c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing. 10*25c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions 11*25c28e83SPiotr Jasiukajtis * and limitations under the License. 12*25c28e83SPiotr Jasiukajtis * 13*25c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each 14*25c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15*25c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the 16*25c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying 17*25c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner] 18*25c28e83SPiotr Jasiukajtis * 19*25c28e83SPiotr Jasiukajtis * CDDL HEADER END 20*25c28e83SPiotr Jasiukajtis */ 21*25c28e83SPiotr Jasiukajtis 22*25c28e83SPiotr Jasiukajtis /* 23*25c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24*25c28e83SPiotr Jasiukajtis */ 25*25c28e83SPiotr Jasiukajtis /* 26*25c28e83SPiotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 27*25c28e83SPiotr Jasiukajtis * Use is subject to license terms. 28*25c28e83SPiotr Jasiukajtis */ 29*25c28e83SPiotr Jasiukajtis 30*25c28e83SPiotr Jasiukajtis #include "libm.h" 31*25c28e83SPiotr Jasiukajtis #include "longdouble.h" 32*25c28e83SPiotr Jasiukajtis 33*25c28e83SPiotr Jasiukajtis /* 34*25c28e83SPiotr Jasiukajtis * exp10l(x) 35*25c28e83SPiotr Jasiukajtis * n = nint(x*(log10/log2)) ; 36*25c28e83SPiotr Jasiukajtis * exp10(x) = 10**x = exp(x*ln(10)) = exp(n*ln2+(x*ln10-n*ln2)) 37*25c28e83SPiotr Jasiukajtis * = 2**n*exp(ln10*(x-n*log2/log10))) 38*25c28e83SPiotr Jasiukajtis * If x is an integer <= M then use repeat multiplication. For 39*25c28e83SPiotr Jasiukajtis * 10**M is the largest representable integer, where 40*25c28e83SPiotr Jasiukajtis * M = 10 single precision (24 bits) 41*25c28e83SPiotr Jasiukajtis * M = 22 double precision (53 bits) 42*25c28e83SPiotr Jasiukajtis * M = 48 quadruple precision (113 bits) 43*25c28e83SPiotr Jasiukajtis */ 44*25c28e83SPiotr Jasiukajtis 45*25c28e83SPiotr Jasiukajtis #define TINY 1.0e-20L /* single: 1e-5, double: 1e-10, quad: 1e-20 */ 46*25c28e83SPiotr Jasiukajtis #define LG10OVT 4933.L /* single: 39, double: 309, quad: 4933 */ 47*25c28e83SPiotr Jasiukajtis #define LG10UFT -4966.L /* single: -45, double: -323, quad: -4966 */ 48*25c28e83SPiotr Jasiukajtis #define M 48 49*25c28e83SPiotr Jasiukajtis /* logt2hi : last 32 bits is zero for quad prec */ 50*25c28e83SPiotr Jasiukajtis #define LOGT2HI 0.30102999566398119521373889472420986034688L 51*25c28e83SPiotr Jasiukajtis #define LOGT2LO 2.831664213089468167896664371953e-31L 52*25c28e83SPiotr Jasiukajtis 53*25c28e83SPiotr Jasiukajtis static const long double 54*25c28e83SPiotr Jasiukajtis zero = 0.0L, 55*25c28e83SPiotr Jasiukajtis tiny = TINY * TINY, 56*25c28e83SPiotr Jasiukajtis one = 1.0L, 57*25c28e83SPiotr Jasiukajtis lg10 = 3.321928094887362347870319429489390175865e+0000L, 58*25c28e83SPiotr Jasiukajtis ln10 = 2.302585092994045684017991454684364207601e+0000L, 59*25c28e83SPiotr Jasiukajtis logt2hi = LOGT2HI, 60*25c28e83SPiotr Jasiukajtis logt2lo = LOGT2LO, 61*25c28e83SPiotr Jasiukajtis lg10ovt = LG10OVT, 62*25c28e83SPiotr Jasiukajtis lg10uft = LG10UFT; 63*25c28e83SPiotr Jasiukajtis 64*25c28e83SPiotr Jasiukajtis long double 65*25c28e83SPiotr Jasiukajtis exp10l(long double x) { 66*25c28e83SPiotr Jasiukajtis long double t, tenp; 67*25c28e83SPiotr Jasiukajtis int k; 68*25c28e83SPiotr Jasiukajtis 69*25c28e83SPiotr Jasiukajtis if (!finitel(x)) { 70*25c28e83SPiotr Jasiukajtis if (isnanl(x) || x > zero) 71*25c28e83SPiotr Jasiukajtis return (x + x); 72*25c28e83SPiotr Jasiukajtis else 73*25c28e83SPiotr Jasiukajtis return (zero); 74*25c28e83SPiotr Jasiukajtis } 75*25c28e83SPiotr Jasiukajtis if (fabsl(x) < tiny) 76*25c28e83SPiotr Jasiukajtis return (one + x); 77*25c28e83SPiotr Jasiukajtis if (x <= lg10ovt) 78*25c28e83SPiotr Jasiukajtis if (x >= lg10uft) { 79*25c28e83SPiotr Jasiukajtis k = (int) x; 80*25c28e83SPiotr Jasiukajtis tenp = 10.0L; 81*25c28e83SPiotr Jasiukajtis /* x is a small +integer */ 82*25c28e83SPiotr Jasiukajtis if (0 <= k && k <= M && (long double) k == x) { 83*25c28e83SPiotr Jasiukajtis t = one; 84*25c28e83SPiotr Jasiukajtis if (k & 1) 85*25c28e83SPiotr Jasiukajtis t *= tenp; 86*25c28e83SPiotr Jasiukajtis k >>= 1; 87*25c28e83SPiotr Jasiukajtis while (k) { 88*25c28e83SPiotr Jasiukajtis tenp *= tenp; 89*25c28e83SPiotr Jasiukajtis if (k & 1) 90*25c28e83SPiotr Jasiukajtis t *= tenp; 91*25c28e83SPiotr Jasiukajtis k >>= 1; 92*25c28e83SPiotr Jasiukajtis } 93*25c28e83SPiotr Jasiukajtis return (t); 94*25c28e83SPiotr Jasiukajtis } 95*25c28e83SPiotr Jasiukajtis t = anintl(x * lg10); 96*25c28e83SPiotr Jasiukajtis return (scalbnl(expl(ln10 * ((x - t * logt2hi) - 97*25c28e83SPiotr Jasiukajtis t * logt2lo)), (int) t)); 98*25c28e83SPiotr Jasiukajtis } else 99*25c28e83SPiotr Jasiukajtis return (scalbnl(one, -50000)); /* underflow */ 100*25c28e83SPiotr Jasiukajtis else 101*25c28e83SPiotr Jasiukajtis return (scalbnl(one, 50000)); /* overflow */ 102*25c28e83SPiotr Jasiukajtis } 103