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      1 /*	$NetBSD: n_sincos.c,v 1.11 2024/07/16 14:53:17 riastradh Exp $	*/
      2 /*
      3  * Copyright (c) 1987, 1993
      4  *	The Regents of the University of California.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. Neither the name of the University nor the names of its contributors
     15  *    may be used to endorse or promote products derived from this software
     16  *    without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 __RCSID("$NetBSD: n_sincos.c,v 1.11 2024/07/16 14:53:17 riastradh Exp $");
     33 
     34 #ifndef lint
     35 #if 0
     36 static char sccsid[] = "@(#)sincos.c	8.1 (Berkeley) 6/4/93";
     37 #endif
     38 #endif /* not lint */
     39 
     40 #define _LIBM_DECLARE
     41 #include "namespace.h"
     42 #include "mathimpl.h"
     43 #include "trig.h"
     44 
     45 __weak_alias(sinl, _sinl)
     46 __strong_alias(_sinl, _sin)
     47 
     48 __weak_alias(cosl, _cosl)
     49 __strong_alias(_cosl, _cos)
     50 
     51 __weak_alias(sin, _sin)
     52 double
     53 sin(double x)
     54 {
     55 	double a,c,z;
     56 
     57         if(!finite(x))		/* sin(NaN) and sin(INF) must be NaN */
     58 		return x-x;
     59 	x=drem(x,PI2);		/* reduce x into [-PI,PI] */
     60 	a=copysign(x,__one);
     61 	if (a >= PIo4) {
     62 		if(a >= PI3o4)		/* ... in [3PI/4,PI] */
     63 			x = copysign((a = PI-a),x);
     64 		else {			/* ... in [PI/4,3PI/4]  */
     65 			a = PIo2-a;		/* rtn. sign(x)*C(PI/2-|x|) */
     66 			z = a*a;
     67 			c = cos__C(z);
     68 			z *= __half;
     69 			a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c));
     70 			return copysign(a,x);
     71 		}
     72 	}
     73 
     74 	if (a < __small) {		/* rtn. S(x) */
     75 		z = __big+a;
     76 		return x;
     77 	}
     78 	return x+x*sin__S(x*x);
     79 }
     80 
     81 __weak_alias(sinf, _sinf)
     82 float
     83 sinf(float x)
     84 {
     85 	return sin(x);
     86 }
     87 
     88 __weak_alias(cos, _cos)
     89 double
     90 cos(double x)
     91 {
     92 	double a,c,z,s = 1.0;
     93 
     94 	if(!finite(x))		/* cos(NaN) and cos(INF) must be NaN */
     95 		return x-x;
     96 	x=drem(x,PI2);		/* reduce x into [-PI,PI] */
     97 	a=copysign(x,__one);
     98 	if (a >= PIo4) {
     99 		if (a >= PI3o4) {	/* ... in [3PI/4,PI] */
    100 			a = PI-a;
    101 			s = __negone;
    102 		}
    103 		else {			/* ... in [PI/4,3PI/4] */
    104 			a = PIo2-a;
    105 			return a+a*sin__S(a*a);	/* rtn. S(PI/2-|x|) */
    106 		}
    107 	}
    108 	if (a < __small) {
    109 		z = __big+a;
    110 		return s;		/* rtn. s*C(a) */
    111 	}
    112 	z = a*a;
    113 	c = cos__C(z);
    114 	z *= __half;
    115 	a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c));
    116 	return copysign(a,s);
    117 }
    118 
    119 __weak_alias(cosf, _cosf)
    120 float
    121 cosf(float x)
    122 {
    123 	return cos(x);
    124 }
    125