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 } 116