lib/libm/noieee_src/n_sincos.c

   1 /*      $NetBSD: n_sincos.c,v 1.5 2002/06/23 21:54:37 matt 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 double
  42 sin(double x)
  43 {
  44         double a,c,z;
  45
  46         if(!finite(x))          /* sin(NaN) and sin(INF) must be NaN */
  47                 return x-x;
  48         x=drem(x,PI2);          /* reduce x into [-PI,PI] */
  49         a=copysign(x,__one);
  50         if (a >= PIo4) {
  51                 if(a >= PI3o4)          /* ... in [3PI/4,PI] */
  52                         x = copysign((a = PI-a),x);
  53                 else {                  /* ... in [PI/4,3PI/4]  */
  54                         a = PIo2-a;             /* rtn. sign(x)*C(PI/2-|x|) */
  55                         z = a*a;
  56                         c = cos__C(z);
  57                         z *= __half;
  58                         a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c));
  59                         return copysign(a,x);
  60                 }
  61         }
  62
  63         if (a < __small) {              /* rtn. S(x) */
  64                 z = __big+a;
  65                 return x;
  66         }
  67         return x+x*sin__S(x*x);
  68 }
  69
  70 float
  71 sinf(float x)
  72 {
  73         return sin(x);
  74 }
  75
  76 double
  77 cos(double x)
  78 {
  79         double a,c,z,s = 1.0;
  80
  81         if(!finite(x))          /* cos(NaN) and cos(INF) must be NaN */
  82                 return x-x;
  83         x=drem(x,PI2);          /* reduce x into [-PI,PI] */
  84         a=copysign(x,__one);
  85         if (a >= PIo4) {
  86                 if (a >= PI3o4) {       /* ... in [3PI/4,PI] */
  87                         a = PI-a;
  88                         s = __negone;
  89                 }
  90                 else {                  /* ... in [PI/4,3PI/4] */
  91                         a = PIo2-a;
  92                         return a+a*sin__S(a*a); /* rtn. S(PI/2-|x|) */
  93                 }
  94         }
  95         if (a < __small) {
  96                 z = __big+a;
  97                 return s;               /* rtn. s*C(a) */
  98         }
  99         z = a*a;
 100         c = cos__C(z);
 101         z *= __half;
 102         a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c));
 103         return copysign(a,s);
 104 }
 105
 106 float
 107 cosf(float x)
 108 {
 109         return cos(x);
 110 }