| /* origin: FreeBSD /usr/src/lib/msun/src/k_cosf.c */ |
| /* |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| * Debugged and optimized by Bruce D. Evans. |
| */ |
| /* |
| * ==================================================== |
| * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| * |
| * Developed at SunPro, a Sun Microsystems, Inc. business. |
| * Permission to use, copy, modify, and distribute this |
| * software is freely granted, provided that this notice |
| * is preserved. |
| * ==================================================== |
| */ |
| |
| #include "libm.h" |
| |
| /* |cos(x) - c(x)| < 2**-34.1 (~[-5.37e-11, 5.295e-11]). */ |
| static const double |
| C0 = -0x1ffffffd0c5e81.0p-54, /* -0.499999997251031003120 */ |
| C1 = 0x155553e1053a42.0p-57, /* 0.0416666233237390631894 */ |
| C2 = -0x16c087e80f1e27.0p-62, /* -0.00138867637746099294692 */ |
| C3 = 0x199342e0ee5069.0p-68; /* 0.0000243904487962774090654 */ |
| |
| float __cosdf(double x) |
| { |
| double_t r, w, z; |
| |
| /* Try to optimize for parallel evaluation as in __tandf.c. */ |
| z = x*x; |
| w = z*z; |
| r = C2+z*C3; |
| return ((1.0+z*C0) + w*C1) + (w*z)*r; |
| } |
