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[] = "$FreeBSD$"; 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 } 48