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. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Berkeley and its contributors. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)sincos.c 8.1 (Berkeley) 6/4/93"; 38 #endif 39 #endif /* not lint */ 40 41 #define _LIBM_DECLARE 42 #include "mathimpl.h" 43 #include "trig.h" 44 45 double 46 sin(double x) 47 { 48 double a,c,z; 49 50 if(!finite(x)) /* sin(NaN) and sin(INF) must be NaN */ 51 return x-x; 52 x=drem(x,PI2); /* reduce x into [-PI,PI] */ 53 a=copysign(x,__one); 54 if (a >= PIo4) { 55 if(a >= PI3o4) /* ... in [3PI/4,PI] */ 56 x = copysign((a = PI-a),x); 57 else { /* ... in [PI/4,3PI/4] */ 58 a = PIo2-a; /* rtn. sign(x)*C(PI/2-|x|) */ 59 z = a*a; 60 c = cos__C(z); 61 z *= __half; 62 a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c)); 63 return copysign(a,x); 64 } 65 } 66 67 if (a < __small) { /* rtn. S(x) */ 68 z = __big+a; 69 return x; 70 } 71 return x+x*sin__S(x*x); 72 } 73 74 float 75 sinf(float x) 76 { 77 return sin(x); 78 } 79 80 double 81 cos(double x) 82 { 83 double a,c,z,s = 1.0; 84 85 if(!finite(x)) /* cos(NaN) and cos(INF) must be NaN */ 86 return x-x; 87 x=drem(x,PI2); /* reduce x into [-PI,PI] */ 88 a=copysign(x,__one); 89 if (a >= PIo4) { 90 if (a >= PI3o4) { /* ... in [3PI/4,PI] */ 91 a = PI-a; 92 s = __negone; 93 } 94 else { /* ... in [PI/4,3PI/4] */ 95 a = PIo2-a; 96 return a+a*sin__S(a*a); /* rtn. S(PI/2-|x|) */ 97 } 98 } 99 if (a < __small) { 100 z = __big+a; 101 return s; /* rtn. s*C(a) */ 102 } 103 z = a*a; 104 c = cos__C(z); 105 z *= __half; 106 a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c)); 107 return copysign(a,s); 108 } 109 110 float 111 cosf(float x) 112 { 113 return cos(x); 114 } 115