diff options
Diffstat (limited to 'libm/src/k_cosf.c')
-rw-r--r-- | libm/src/k_cosf.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/libm/src/k_cosf.c b/libm/src/k_cosf.c new file mode 100644 index 0000000..ff08d5f --- /dev/null +++ b/libm/src/k_cosf.c @@ -0,0 +1,47 @@ +/* k_cosf.c -- float version of k_cos.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. + * ==================================================== + */ + +#ifndef INLINE_KERNEL_COSDF +#ifndef lint +static char rcsid[] = "$FreeBSD: src/lib/msun/src/k_cosf.c,v 1.15 2005/11/30 11:51:17 bde Exp $"; +#endif +#endif + +#include "math.h" +#include "math_private.h" + +/* |cos(x) - c(x)| < 2**-34.1 (~[-5.37e-11, 5.295e-11]). */ +static const double +one = 1.0, +C0 = -0x1ffffffd0c5e81.0p-54, /* -0.499999997251031003120 */ +C1 = 0x155553e1053a42.0p-57, /* 0.0416666233237390631894 */ +C2 = -0x16c087e80f1e27.0p-62, /* -0.00138867637746099294692 */ +C3 = 0x199342e0ee5069.0p-68; /* 0.0000243904487962774090654 */ + +#ifdef INLINE_KERNEL_COSDF +extern inline +#endif +float +__kernel_cosdf(double x) +{ + double r, w, z; + + /* Try to optimize for parallel evaluation as in k_tanf.c. */ + z = x*x; + w = z*z; + r = C2+z*C3; + return ((one+z*C0) + w*C1) + (w*z)*r; +} |