1 /* s_cosf.c -- float version of s_cos.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16 #include <sys/cdefs.h>
17 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: s_cosf.c,v 1.9 2007/08/20 16:01:39 drochner Exp $");
19 #endif
20
21 #include "namespace.h"
22 #include "math.h"
23 #include "math_private.h"
24
25 #if 0 /* notyet */
26 #ifdef __weak_alias
27 __weak_alias(cosf, _cosf)
28 #endif
29 #endif
30
31 #if 0
32 static const float one=1.0;
33 #endif
34
35 float
cosf(float x)36 cosf(float x)
37 {
38 float y[2],z=0.0;
39 int32_t n,ix;
40
41 GET_FLOAT_WORD(ix,x);
42
43 /* |x| ~< pi/4 */
44 ix &= 0x7fffffff;
45 if(ix <= 0x3f490fd8) return __kernel_cosf(x,z);
46
47 /* cos(Inf or NaN) is NaN */
48 else if (ix>=0x7f800000) return x-x;
49
50 /* argument reduction needed */
51 else {
52 n = __ieee754_rem_pio2f(x,y);
53 switch(n&3) {
54 case 0: return __kernel_cosf(y[0],y[1]);
55 case 1: return -__kernel_sinf(y[0],y[1],1);
56 case 2: return -__kernel_cosf(y[0],y[1]);
57 default:
58 return __kernel_sinf(y[0],y[1],1);
59 }
60 }
61 }
62