1 /* $NetBSD: n_sincos.c,v 1.11 2024/07/16 14:53:17 riastradh 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 #include <sys/cdefs.h> 32 __RCSID("$NetBSD: n_sincos.c,v 1.11 2024/07/16 14:53:17 riastradh Exp $"); 33 34 #ifndef lint 35 #if 0 36 static char sccsid[] = "@(#)sincos.c 8.1 (Berkeley) 6/4/93"; 37 #endif 38 #endif /* not lint */ 39 40 #define _LIBM_DECLARE 41 #include "namespace.h" 42 #include "mathimpl.h" 43 #include "trig.h" 44 45 __weak_alias(sinl, _sinl) 46 __strong_alias(_sinl, _sin) 47 48 __weak_alias(cosl, _cosl) 49 __strong_alias(_cosl, _cos) 50 51 __weak_alias(sin, _sin) 52 double 53 sin(double x) 54 { 55 double a,c,z; 56 57 if(!finite(x)) /* sin(NaN) and sin(INF) must be NaN */ 58 return x-x; 59 x=drem(x,PI2); /* reduce x into [-PI,PI] */ 60 a=copysign(x,__one); 61 if (a >= PIo4) { 62 if(a >= PI3o4) /* ... in [3PI/4,PI] */ 63 x = copysign((a = PI-a),x); 64 else { /* ... in [PI/4,3PI/4] */ 65 a = PIo2-a; /* rtn. sign(x)*C(PI/2-|x|) */ 66 z = a*a; 67 c = cos__C(z); 68 z *= __half; 69 a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c)); 70 return copysign(a,x); 71 } 72 } 73 74 if (a < __small) { /* rtn. S(x) */ 75 z = __big+a; 76 return x; 77 } 78 return x+x*sin__S(x*x); 79 } 80 81 __weak_alias(sinf, _sinf) 82 float 83 sinf(float x) 84 { 85 return sin(x); 86 } 87 88 __weak_alias(cos, _cos) 89 double 90 cos(double x) 91 { 92 double a,c,z,s = 1.0; 93 94 if(!finite(x)) /* cos(NaN) and cos(INF) must be NaN */ 95 return x-x; 96 x=drem(x,PI2); /* reduce x into [-PI,PI] */ 97 a=copysign(x,__one); 98 if (a >= PIo4) { 99 if (a >= PI3o4) { /* ... in [3PI/4,PI] */ 100 a = PI-a; 101 s = __negone; 102 } 103 else { /* ... in [PI/4,3PI/4] */ 104 a = PIo2-a; 105 return a+a*sin__S(a*a); /* rtn. S(PI/2-|x|) */ 106 } 107 } 108 if (a < __small) { 109 z = __big+a; 110 return s; /* rtn. s*C(a) */ 111 } 112 z = a*a; 113 c = cos__C(z); 114 z *= __half; 115 a = (z >= thresh ? __half-((z-__half)-c) : __one-(z-c)); 116 return copysign(a,s); 117 } 118 119 __weak_alias(cosf, _cosf) 120 float 121 cosf(float x) 122 { 123 return cos(x); 124 } 125