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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include "libm.h"
/* INDENT OFF */
/*
* float __k_sin(double x);
* kernel (float) sin function on [-pi/4, pi/4], pi/4 ~ 0.785398164
* Input x is in double and assumed to be bounded by ~pi/4 in magnitude.
*
* Method: Let z = x * x, then
* S(x) = x(S0 + S1*z)(S2 + S3*z + z*z)
* where
* S0 = 1.85735322054308378716204874632872525989806770558e-0003,
* S1 = -1.95035094218403635082921458859320791358115801259e-0004,
* S2 = 5.38400550766074785970952495168558701485841707252e+0002,
* S3 = -3.31975110777873728964197739157371509422022905947e+0001,
*
* The remez error is bound by |(sin(x) - S(x))/x| < 2**(-28.2)
*
* Constants:
* The hexadecimal values are the intended ones for the following constants.
* The decimal values may be used, provided that the compiler will convert
* from decimal to binary accurately enough to produce the hexadecimal values
* shown.
*/
/* INDENT ON */
static const double q[] = {
/* S0 = */ 1.85735322054308378716204874632872525989806770558e-0003,
/* S1 = */ -1.95035094218403635082921458859320791358115801259e-0004,
/* S2 = */ 5.38400550766074785970952495168558701485841707252e+0002,
/* S3 = */ -3.31975110777873728964197739157371509422022905947e+0001,
};
#define S0 q[0]
#define S1 q[1]
#define S2 q[2]
#define S3 q[3]
float
__k_sinf(double x) {
float ft;
double z;
int hx;
hx = ((int *) &x)[HIWORD]; /* hx = leading x */
if ((hx & ~0x80000000) < 0x3f100000) { /* if |x| < 2**-14 */
ft = (float) x;
if ((int) x == 0) /* raise inexact if x != 0 */
return (ft);
}
z = x * x;
ft = (float) ((x * (S0 + z * S1)) * (S2 + z * (S3 + z)));
return (ft);
}
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