__cosf.c revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
/*
* 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
* 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_cos(double x);
* kernel (float) cos 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
* C(x) = (C0 + C1*z + C2*z*z) * (C3 + C4*z + z*z)
* where
* C0 = 1.09349482127188401868272000389539985058873853699e-0003
* C1 = -5.03324285989964979398034700054920226866107675091e-0004
* C2 = 2.43792880266971107750418061559602239831538067410e-0005
* C3 = 9.14499072605666582228127405245558035523741471271e+0002
* C4 = -3.63151270591815439197122504991683846785293207730e+0001
*
* The remez error is bound by |cos(x) - C(x)| < 2**(-34.2)
*
* 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[] = {
/* C0 = */ 1.09349482127188401868272000389539985058873853699e-0003,
/* C1 = */ -5.03324285989964979398034700054920226866107675091e-0004,
/* C2 = */ 2.43792880266971107750418061559602239831538067410e-0005,
/* C3 = */ 9.14499072605666582228127405245558035523741471271e+0002,
/* C4 = */ -3.63151270591815439197122504991683846785293207730e+0001,
};
#define C0 q[0]
#define C1 q[1]
#define C2 q[2]
#define C3 q[3]
#define C4 q[4]
float
__k_cosf(double x) {
float ft;
double z;
int hx;
ft = (float) 1;
if (((int) x) == 0) /* raise inexact if x != 0 */
return (ft);
}
z = x * x;
return (ft);
}