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
__k_sinf(double x)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