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_sin(double x); 35*25c28e83SPiotr Jasiukajtis * kernel (float) sin 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 * Method: Let z = x * x, then 39*25c28e83SPiotr Jasiukajtis * S(x) = x(S0 + S1*z)(S2 + S3*z + z*z) 40*25c28e83SPiotr Jasiukajtis * where 41*25c28e83SPiotr Jasiukajtis * S0 = 1.85735322054308378716204874632872525989806770558e-0003, 42*25c28e83SPiotr Jasiukajtis * S1 = -1.95035094218403635082921458859320791358115801259e-0004, 43*25c28e83SPiotr Jasiukajtis * S2 = 5.38400550766074785970952495168558701485841707252e+0002, 44*25c28e83SPiotr Jasiukajtis * S3 = -3.31975110777873728964197739157371509422022905947e+0001, 45*25c28e83SPiotr Jasiukajtis * 46*25c28e83SPiotr Jasiukajtis * The remez error is bound by |(sin(x) - S(x))/x| < 2**(-28.2) 47*25c28e83SPiotr Jasiukajtis * 48*25c28e83SPiotr Jasiukajtis * Constants: 49*25c28e83SPiotr Jasiukajtis * The hexadecimal values are the intended ones for the following constants. 50*25c28e83SPiotr Jasiukajtis * The decimal values may be used, provided that the compiler will convert 51*25c28e83SPiotr Jasiukajtis * from decimal to binary accurately enough to produce the hexadecimal values 52*25c28e83SPiotr Jasiukajtis * shown. 53*25c28e83SPiotr Jasiukajtis */ 54*25c28e83SPiotr Jasiukajtis /* INDENT ON */ 55*25c28e83SPiotr Jasiukajtis 56*25c28e83SPiotr Jasiukajtis static const double q[] = { 57*25c28e83SPiotr Jasiukajtis /* S0 = */ 1.85735322054308378716204874632872525989806770558e-0003, 58*25c28e83SPiotr Jasiukajtis /* S1 = */ -1.95035094218403635082921458859320791358115801259e-0004, 59*25c28e83SPiotr Jasiukajtis /* S2 = */ 5.38400550766074785970952495168558701485841707252e+0002, 60*25c28e83SPiotr Jasiukajtis /* S3 = */ -3.31975110777873728964197739157371509422022905947e+0001, 61*25c28e83SPiotr Jasiukajtis }; 62*25c28e83SPiotr Jasiukajtis 63*25c28e83SPiotr Jasiukajtis #define S0 q[0] 64*25c28e83SPiotr Jasiukajtis #define S1 q[1] 65*25c28e83SPiotr Jasiukajtis #define S2 q[2] 66*25c28e83SPiotr Jasiukajtis #define S3 q[3] 67*25c28e83SPiotr Jasiukajtis 68*25c28e83SPiotr Jasiukajtis float 69*25c28e83SPiotr Jasiukajtis __k_sinf(double x) { 70*25c28e83SPiotr Jasiukajtis float ft; 71*25c28e83SPiotr Jasiukajtis double z; 72*25c28e83SPiotr Jasiukajtis int hx; 73*25c28e83SPiotr Jasiukajtis 74*25c28e83SPiotr Jasiukajtis hx = ((int *) &x)[HIWORD]; /* hx = leading x */ 75*25c28e83SPiotr Jasiukajtis if ((hx & ~0x80000000) < 0x3f100000) { /* if |x| < 2**-14 */ 76*25c28e83SPiotr Jasiukajtis ft = (float) x; 77*25c28e83SPiotr Jasiukajtis if ((int) x == 0) /* raise inexact if x != 0 */ 78*25c28e83SPiotr Jasiukajtis return (ft); 79*25c28e83SPiotr Jasiukajtis } 80*25c28e83SPiotr Jasiukajtis z = x * x; 81*25c28e83SPiotr Jasiukajtis ft = (float) ((x * (S0 + z * S1)) * (S2 + z * (S3 + z))); 82*25c28e83SPiotr Jasiukajtis return (ft); 83*25c28e83SPiotr Jasiukajtis } 84