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n_sincos.c revision 1.9 
      1 /*	$NetBSD: n_sincos.c,v 1.9 2022/08/27 09:56:21 christos 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 #ifndef lint
     32 #if 0
     33 static char sccsid[] = "@(#)sincos.c	8.1 (Berkeley) 6/4/93";
     34 #endif
     35 #endif /* not lint */
     36 
     37 #define _LIBM_DECLARE
     38 #include "mathimpl.h"
     39 #include "trig.h"
     40 
     41 #ifdef __weak_alias
     42 __weak_alias(_sinl, sin);
     43 __weak_alias(_cosl, cos);
     44 #endif
     45 
     46 double
     47 sin(double x)
     48 {
     49 	double a,c,z;
     50 
     51         if(!finite(x))		/* sin(NaN) and sin(INF) must be NaN */
     52 		return x-x;
     53 	x=drem(x,PI2);		/* reduce x into [-PI,PI] */
     54 	a=copysign(x,__one);
     55 	if (a >= PIo4) {
     56 		if(a >= PI3o4)		/* ... in [3PI/4,PI] */
     57 			x = copysign((a = PI-a),x);
     58 		else {			/* ... in [PI/4,3PI/4]  */
     59 			a = PIo2-a;		/* rtn. sign(x)*C(PI/2-|x|) */
     60 			z = a*a;
     61 			c = cos__C(z);
     62 			z *= __half;
     63 			a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c));
     64 			return copysign(a,x);
     65 		}
     66 	}
     67 
     68 	if (a < __small) {		/* rtn. S(x) */
     69 		z = __big+a;
     70 		return x;
     71 	}
     72 	return x+x*sin__S(x*x);
     73 }
     74 
     75 float
     76 sinf(float x)
     77 {
     78 	return sin(x);
     79 }
     80 
     81 double
     82 cos(double x)
     83 {
     84 	double a,c,z,s = 1.0;
     85 
     86 	if(!finite(x))		/* cos(NaN) and cos(INF) must be NaN */
     87 		return x-x;
     88 	x=drem(x,PI2);		/* reduce x into [-PI,PI] */
     89 	a=copysign(x,__one);
     90 	if (a >= PIo4) {
     91 		if (a >= PI3o4) {	/* ... in [3PI/4,PI] */
     92 			a = PI-a;
     93 			s = __negone;
     94 		}
     95 		else {			/* ... in [PI/4,3PI/4] */
     96 			a = PIo2-a;
     97 			return a+a*sin__S(a*a);	/* rtn. S(PI/2-|x|) */
     98 		}
     99 	}
    100 	if (a < __small) {
    101 		z = __big+a;
    102 		return s;		/* rtn. s*C(a) */
    103 	}
    104 	z = a*a;
    105 	c = cos__C(z);
    106 	z *= __half;
    107 	a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c));
    108 	return copysign(a,s);
    109 }
    110 
    111 float
    112 cosf(float x)
    113 {
    114 	return cos(x);
    115 }
    116 
    117 void
    118 sincos(double x, double *s, double *c)
    119 {
    120 	*s = sin(x);
    121 	*c = cos(x);
    122 }
    123 
    124 void
    125 sincosf(float x, float *s, float *c)
    126 {
    127 	*s = sinf(x);
    128 	*c = cosf(x);
    129 }
    130