lib/libm/noieee_src/n_sincos.c

   1 /*      $NetBSD: n_sincos.c,v 1.7 2014/10/10 20:58:09 martin 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 }