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
sin(double x)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
sinf(float x)76 sinf(float x)
77 {
78 return sin(x);
79 }
80
81 double
cos(double x)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
cosf(float x)112 cosf(float x)
113 {
114 return cos(x);
115 }
116