Update.
[glibc.git] / sysdeps / libm-ieee754 / k_cosf.c
blobb232cab11f580200e2eb6b4d8503aa3a5d1c55d0
1 /* k_cosf.c -- float version of k_cos.c
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 * ====================================================
16 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: k_cosf.c,v 1.4 1995/05/10 20:46:23 jtc Exp $";
18 #endif
20 #include "math.h"
21 #include "math_private.h"
23 #ifdef __STDC__
24 static const float
25 #else
26 static float
27 #endif
28 one = 1.0000000000e+00, /* 0x3f800000 */
29 C1 = 4.1666667908e-02, /* 0x3d2aaaab */
30 C2 = -1.3888889225e-03, /* 0xbab60b61 */
31 C3 = 2.4801587642e-05, /* 0x37d00d01 */
32 C4 = -2.7557314297e-07, /* 0xb493f27c */
33 C5 = 2.0875723372e-09, /* 0x310f74f6 */
34 C6 = -1.1359647598e-11; /* 0xad47d74e */
36 #ifdef __STDC__
37 float __kernel_cosf(float x, float y)
38 #else
39 float __kernel_cosf(x, y)
40 float x,y;
41 #endif
43 float a,hz,z,r,qx;
44 int32_t ix;
45 GET_FLOAT_WORD(ix,x);
46 ix &= 0x7fffffff; /* ix = |x|'s high word*/
47 if(ix<0x32000000) { /* if x < 2**27 */
48 if(((int)x)==0) return one; /* generate inexact */
50 z = x*x;
51 r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
52 if(ix < 0x3e99999a) /* if |x| < 0.3 */
53 return one - ((float)0.5*z - (z*r - x*y));
54 else {
55 if(ix > 0x3f480000) { /* x > 0.78125 */
56 qx = (float)0.28125;
57 } else {
58 SET_FLOAT_WORD(qx,ix-0x01000000); /* x/4 */
60 hz = (float)0.5*z-qx;
61 a = one-qx;
62 return a - (hz - (z*r-x*y));