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Diffstat (limited to 'newlib/libm/ld128/k_cosl.c')
-rw-r--r-- | newlib/libm/ld128/k_cosl.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/newlib/libm/ld128/k_cosl.c b/newlib/libm/ld128/k_cosl.c new file mode 100644 index 000000000..680787307 --- /dev/null +++ b/newlib/libm/ld128/k_cosl.c @@ -0,0 +1,59 @@ +/* From: @(#)k_cos.c 1.3 95/01/18 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * Copyright (c) 2008 Steven G. Kargl, David Schultz, Bruce D. Evans. + * + * Developed at SunSoft, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * ld128 version of k_cos.c. See ../src/k_cos.c for most comments. + */ + +#include "math_private.h" + +/* + * Domain [-0.7854, 0.7854], range ~[-1.17e-39, 1.19e-39]: + * |cos(x) - c(x))| < 2**-129.3 + * + * 113-bit precision requires more care than 64-bit precision, since + * simple methods give a minimax polynomial with coefficient for x^2 + * that is 1 ulp below 0.5, but we want it to be precisely 0.5. See + * ../ld80/k_cosl.c for more details. + */ +static const double +one = 1.0; +static const long double +C1 = 4.16666666666666666666666666666666667e-02L, +C2 = -1.38888888888888888888888888888888834e-03L, +C3 = 2.48015873015873015873015873015446795e-05L, +C4 = -2.75573192239858906525573190949988493e-07L, +C5 = 2.08767569878680989792098886701451072e-09L, +C6 = -1.14707455977297247136657111139971865e-11L, +C7 = 4.77947733238738518870113294139830239e-14L, +C8 = -1.56192069685858079920640872925306403e-16L, +C9 = 4.11031762320473354032038893429515732e-19L, +C10= -8.89679121027589608738005163931958096e-22L, +C11= 1.61171797801314301767074036661901531e-24L, +C12= -2.46748624357670948912574279501044295e-27L; + +long double +__kernel_cosl(long double x, long double y) +{ + long double hz,z,r,w; + + z = x*x; + r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*(C6+z*(C7+ + z*(C8+z*(C9+z*(C10+z*(C11+z*C12))))))))))); + hz = 0.5*z; + w = one-hz; + return w + (((one-w)-hz) + (z*r-x*y)); +} |