1*2fe8fb19SBen Gras /* k_cosf.c -- float version of k_cos.c
2*2fe8fb19SBen Gras * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*2fe8fb19SBen Gras */
4*2fe8fb19SBen Gras
5*2fe8fb19SBen Gras /*
6*2fe8fb19SBen Gras * ====================================================
7*2fe8fb19SBen Gras * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*2fe8fb19SBen Gras *
9*2fe8fb19SBen Gras * Developed at SunPro, a Sun Microsystems, Inc. business.
10*2fe8fb19SBen Gras * Permission to use, copy, modify, and distribute this
11*2fe8fb19SBen Gras * software is freely granted, provided that this notice
12*2fe8fb19SBen Gras * is preserved.
13*2fe8fb19SBen Gras * ====================================================
14*2fe8fb19SBen Gras */
15*2fe8fb19SBen Gras
16*2fe8fb19SBen Gras #include <sys/cdefs.h>
17*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
18*2fe8fb19SBen Gras __RCSID("$NetBSD: k_cosf.c,v 1.7 2002/05/26 22:01:53 wiz Exp $");
19*2fe8fb19SBen Gras #endif
20*2fe8fb19SBen Gras
21*2fe8fb19SBen Gras #include "math.h"
22*2fe8fb19SBen Gras #include "math_private.h"
23*2fe8fb19SBen Gras
24*2fe8fb19SBen Gras static const float
25*2fe8fb19SBen Gras one = 1.0000000000e+00, /* 0x3f800000 */
26*2fe8fb19SBen Gras C1 = 4.1666667908e-02, /* 0x3d2aaaab */
27*2fe8fb19SBen Gras C2 = -1.3888889225e-03, /* 0xbab60b61 */
28*2fe8fb19SBen Gras C3 = 2.4801587642e-05, /* 0x37d00d01 */
29*2fe8fb19SBen Gras C4 = -2.7557314297e-07, /* 0xb493f27c */
30*2fe8fb19SBen Gras C5 = 2.0875723372e-09, /* 0x310f74f6 */
31*2fe8fb19SBen Gras C6 = -1.1359647598e-11; /* 0xad47d74e */
32*2fe8fb19SBen Gras
33*2fe8fb19SBen Gras float
__kernel_cosf(float x,float y)34*2fe8fb19SBen Gras __kernel_cosf(float x, float y)
35*2fe8fb19SBen Gras {
36*2fe8fb19SBen Gras float a,hz,z,r,qx;
37*2fe8fb19SBen Gras int32_t ix;
38*2fe8fb19SBen Gras GET_FLOAT_WORD(ix,x);
39*2fe8fb19SBen Gras ix &= 0x7fffffff; /* ix = |x|'s high word*/
40*2fe8fb19SBen Gras if(ix<0x32000000) { /* if x < 2**27 */
41*2fe8fb19SBen Gras if(((int)x)==0) return one; /* generate inexact */
42*2fe8fb19SBen Gras }
43*2fe8fb19SBen Gras z = x*x;
44*2fe8fb19SBen Gras r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
45*2fe8fb19SBen Gras if(ix < 0x3e99999a) /* if |x| < 0.3 */
46*2fe8fb19SBen Gras return one - ((float)0.5*z - (z*r - x*y));
47*2fe8fb19SBen Gras else {
48*2fe8fb19SBen Gras if(ix > 0x3f480000) { /* x > 0.78125 */
49*2fe8fb19SBen Gras qx = (float)0.28125;
50*2fe8fb19SBen Gras } else {
51*2fe8fb19SBen Gras SET_FLOAT_WORD(qx,ix-0x01000000); /* x/4 */
52*2fe8fb19SBen Gras }
53*2fe8fb19SBen Gras hz = (float)0.5*z-qx;
54*2fe8fb19SBen Gras a = one-qx;
55*2fe8fb19SBen Gras return a - (hz - (z*r-x*y));
56*2fe8fb19SBen Gras }
57*2fe8fb19SBen Gras }
58