1 /* k_cosf.c -- float version of k_cos.c
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 * Debugged and optimized by Bruce D. Evans.
4 */
5
6 /*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17 #ifndef INLINE_KERNEL_COSDF
18 #include <sys/cdefs.h>
19 __FBSDID("$FreeBSD$");
20 #endif
21
22 #include "math.h"
23 #include "math_private.h"
24
25 /* |cos(x) - c(x)| < 2**-34.1 (~[-5.37e-11, 5.295e-11]). */
26 static const double
27 one = 1.0,
28 C0 = -0x1ffffffd0c5e81.0p-54, /* -0.499999997251031003120 */
29 C1 = 0x155553e1053a42.0p-57, /* 0.0416666233237390631894 */
30 C2 = -0x16c087e80f1e27.0p-62, /* -0.00138867637746099294692 */
31 C3 = 0x199342e0ee5069.0p-68; /* 0.0000243904487962774090654 */
32
33 #ifdef INLINE_KERNEL_COSDF
34 static __inline
35 #endif
36 float
__kernel_cosdf(double x)37 __kernel_cosdf(double x)
38 {
39 double r, w, z;
40
41 /* Try to optimize for parallel evaluation as in k_tanf.c. */
42 z = x*x;
43 w = z*z;
44 r = C2+z*C3;
45 return ((one+z*C0) + w*C1) + (w*z)*r;
46 }
47