1/* k_cosf.c -- float version of k_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#if defined(LIBM_SCCS) && !defined(lint)
17static char rcsid[] = "$NetBSD: k_cosf.c,v 1.4 1995/05/10 20:46:23 jtc Exp $";
18#endif
19
20#include <math.h>
21#include <math_private.h>
22
23static const float
24one = 1.0000000000e+00, /* 0x3f800000 */
25C1 = 4.1666667908e-02, /* 0x3d2aaaab */
26C2 = -1.3888889225e-03, /* 0xbab60b61 */
27C3 = 2.4801587642e-05, /* 0x37d00d01 */
28C4 = -2.7557314297e-07, /* 0xb493f27c */
29C5 = 2.0875723372e-09, /* 0x310f74f6 */
30C6 = -1.1359647598e-11; /* 0xad47d74e */
31
32float __kernel_cosf(float x, float y)
33{
34 float a,hz,z,r,qx;
35 int32_t ix;
36 GET_FLOAT_WORD(ix,x);
37 ix &= 0x7fffffff; /* ix = |x|'s high word*/
38 if(ix<0x32000000) { /* if x < 2**27 */
39 if(((int)x)==0) return one; /* generate inexact */
40 }
41 z = x*x;
42 r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
43 if(ix < 0x3e99999a) /* if |x| < 0.3 */
44 return one - ((float)0.5*z - (z*r - x*y));
45 else {
46 if(ix > 0x3f480000) { /* x > 0.78125 */
47 qx = (float)0.28125;
48 } else {
49 SET_FLOAT_WORD(qx,ix-0x01000000); /* x/4 */
50 }
51 hz = (float)0.5*z-qx;
52 a = one-qx;
53 return a - (hz - (z*r-x*y));
54 }
55}
56