| The Android Open Source Project | a27d2ba | 2008-10-21 07:00:00 -0700 | [diff] [blame^] | 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 | #ifndef lint |
| 19 | static char rcsid[] = "$FreeBSD: src/lib/msun/src/k_cosf.c,v 1.15 2005/11/30 11:51:17 bde Exp $"; |
| 20 | #endif |
| 21 | #endif |
| 22 | |
| 23 | #include "math.h" |
| 24 | #include "math_private.h" |
| 25 | |
| 26 | /* |cos(x) - c(x)| < 2**-34.1 (~[-5.37e-11, 5.295e-11]). */ |
| 27 | static const double |
| 28 | one = 1.0, |
| 29 | C0 = -0x1ffffffd0c5e81.0p-54, /* -0.499999997251031003120 */ |
| 30 | C1 = 0x155553e1053a42.0p-57, /* 0.0416666233237390631894 */ |
| 31 | C2 = -0x16c087e80f1e27.0p-62, /* -0.00138867637746099294692 */ |
| 32 | C3 = 0x199342e0ee5069.0p-68; /* 0.0000243904487962774090654 */ |
| 33 | |
| 34 | #ifdef INLINE_KERNEL_COSDF |
| 35 | extern inline |
| 36 | #endif |
| 37 | float |
| 38 | __kernel_cosdf(double x) |
| 39 | { |
| 40 | double r, w, z; |
| 41 | |
| 42 | /* Try to optimize for parallel evaluation as in k_tanf.c. */ |
| 43 | z = x*x; |
| 44 | w = z*z; |
| 45 | r = C2+z*C3; |
| 46 | return ((one+z*C0) + w*C1) + (w*z)*r; |
| 47 | } |