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 32*25c28e83SPiotr Jasiukajtis /* INDENT OFF */ 33*25c28e83SPiotr Jasiukajtis /* 34*25c28e83SPiotr Jasiukajtis * float __k_tan(double x); 35*25c28e83SPiotr Jasiukajtis * kernel (float) tan function on [-pi/4, pi/4], pi/4 ~ 0.785398164 36*25c28e83SPiotr Jasiukajtis * Input x is in double and assumed to be bounded by ~pi/4 in magnitude. 37*25c28e83SPiotr Jasiukajtis * 38*25c28e83SPiotr Jasiukajtis * Constants: 39*25c28e83SPiotr Jasiukajtis * The hexadecimal values are the intended ones for the following constants. 40*25c28e83SPiotr Jasiukajtis * The decimal values may be used, provided that the compiler will convert 41*25c28e83SPiotr Jasiukajtis * from decimal to binary accurately enough to produce the hexadecimal values 42*25c28e83SPiotr Jasiukajtis * shown. 43*25c28e83SPiotr Jasiukajtis */ 44*25c28e83SPiotr Jasiukajtis 45*25c28e83SPiotr Jasiukajtis static const double q[] = { 46*25c28e83SPiotr Jasiukajtis /* one */ 1.0, 47*25c28e83SPiotr Jasiukajtis /* P0 */ 4.46066928428959230679140546271810308098793029785e-0003, 48*25c28e83SPiotr Jasiukajtis /* P1 */ 4.92165316309189027066395283327437937259674072266e+0000, 49*25c28e83SPiotr Jasiukajtis /* P2 */ -7.11410648161473480044492134766187518835067749023e-0001, 50*25c28e83SPiotr Jasiukajtis /* P3 */ 4.08549808374053391446523164631798863410949707031e+0000, 51*25c28e83SPiotr Jasiukajtis /* P4 */ 2.50411070398050927821032018982805311679840087891e+0000, 52*25c28e83SPiotr Jasiukajtis /* P5 */ 1.11492064560251158411574579076841473579406738281e+0001, 53*25c28e83SPiotr Jasiukajtis /* P6 */ -1.50565540968422650891511693771462887525558471680e+0000, 54*25c28e83SPiotr Jasiukajtis /* P7 */ -1.81484378878349295050043110677506774663925170898e+0000, 55*25c28e83SPiotr Jasiukajtis /* T0 */ 3.333335997532835641297409611782510896641e-0001, 56*25c28e83SPiotr Jasiukajtis /* T1 */ 2.999997598248363761541668282006867229939e+00, 57*25c28e83SPiotr Jasiukajtis }; 58*25c28e83SPiotr Jasiukajtis /* INDENT ON */ 59*25c28e83SPiotr Jasiukajtis 60*25c28e83SPiotr Jasiukajtis #define one q[0] 61*25c28e83SPiotr Jasiukajtis #define P0 q[1] 62*25c28e83SPiotr Jasiukajtis #define P1 q[2] 63*25c28e83SPiotr Jasiukajtis #define P2 q[3] 64*25c28e83SPiotr Jasiukajtis #define P3 q[4] 65*25c28e83SPiotr Jasiukajtis #define P4 q[5] 66*25c28e83SPiotr Jasiukajtis #define P5 q[6] 67*25c28e83SPiotr Jasiukajtis #define P6 q[7] 68*25c28e83SPiotr Jasiukajtis #define P7 q[8] 69*25c28e83SPiotr Jasiukajtis #define T0 q[9] 70*25c28e83SPiotr Jasiukajtis #define T1 q[10] 71*25c28e83SPiotr Jasiukajtis 72*25c28e83SPiotr Jasiukajtis float 73*25c28e83SPiotr Jasiukajtis __k_tanf(double x, int n) { 74*25c28e83SPiotr Jasiukajtis float ft = 0.0; 75*25c28e83SPiotr Jasiukajtis double z, w; 76*25c28e83SPiotr Jasiukajtis int ix; 77*25c28e83SPiotr Jasiukajtis 78*25c28e83SPiotr Jasiukajtis ix = ((int *) &x)[HIWORD] & ~0x80000000; /* ix = leading |x| */ 79*25c28e83SPiotr Jasiukajtis /* small argument */ 80*25c28e83SPiotr Jasiukajtis if (ix < 0x3f800000) { /* if |x| < 0.0078125 = 2**-7 */ 81*25c28e83SPiotr Jasiukajtis if (ix < 0x3f100000) { /* if |x| < 2**-14 */ 82*25c28e83SPiotr Jasiukajtis if ((int) x == 0) { /* raise inexact if x != 0 */ 83*25c28e83SPiotr Jasiukajtis ft = n == 0 ? (float) x : (float) (-one / x); 84*25c28e83SPiotr Jasiukajtis } 85*25c28e83SPiotr Jasiukajtis return (ft); 86*25c28e83SPiotr Jasiukajtis } 87*25c28e83SPiotr Jasiukajtis z = (x * T0) * (T1 + x * x); 88*25c28e83SPiotr Jasiukajtis ft = n == 0 ? (float) z : (float) (-one / z); 89*25c28e83SPiotr Jasiukajtis return (ft); 90*25c28e83SPiotr Jasiukajtis } 91*25c28e83SPiotr Jasiukajtis z = x * x; 92*25c28e83SPiotr Jasiukajtis w = ((P0 * x) * (P1 + z * (P2 + z)) * (P3 + z * (P4 + z))) 93*25c28e83SPiotr Jasiukajtis * (P5 + z * (P6 + z * (P7 + z))); 94*25c28e83SPiotr Jasiukajtis ft = n == 0 ? (float) w : (float) (-one / w); 95*25c28e83SPiotr Jasiukajtis return (ft); 96*25c28e83SPiotr Jasiukajtis } 97