/* 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; }