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Diffstat (limited to 'gnulib/lib/cosl.c')
m--------- | gnulib | 0 | ||||
-rw-r--r-- | gnulib/lib/cosl.c | 116 |
2 files changed, 116 insertions, 0 deletions
diff --git a/gnulib b/gnulib deleted file mode 160000 -Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1 diff --git a/gnulib/lib/cosl.c b/gnulib/lib/cosl.c new file mode 100644 index 0000000..a3eaf39 --- /dev/null +++ b/gnulib/lib/cosl.c @@ -0,0 +1,116 @@ +/* s_cosl.c -- long double version of s_sin.c. + * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz. + */ + +/* + * ==================================================== + * 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 <config.h> + +/* Specification. */ +#include <math.h> + +#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE + +long double +cosl (long double x) +{ + return cos (x); +} + +#else + +/* sinl(x) + * Return sine function of x. + * + * kernel function: + * __kernel_sinl ... sine function on [-pi/4,pi/4] + * __kernel_cosl ... cose function on [-pi/4,pi/4] + * __ieee754_rem_pio2l ... argument reduction routine + * + * Method. + * Let S,C and T denote the sin, cos and tan respectively on + * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2 + * in [-pi/4 , +pi/4], and let n = k mod 4. + * We have + * + * n sin(x) cos(x) tan(x) + * ---------------------------------------------------------- + * 0 S C T + * 1 C -S -1/T + * 2 -S -C T + * 3 -C S -1/T + * ---------------------------------------------------------- + * + * Special cases: + * Let trig be any of sin, cos, or tan. + * trig(+-INF) is NaN, with signals; + * trig(NaN) is that NaN; + * + * Accuracy: + * TRIG(x) returns trig(x) nearly rounded + */ + +# include "trigl.h" + +long double +cosl (long double x) +{ + long double y[2],z=0.0L; + int n; + + /* cosl(NaN) is NaN */ + if (isnanl (x)) + return x; + + /* |x| ~< pi/4 */ + if (x >= -0.7853981633974483096156608458198757210492 + && x <= 0.7853981633974483096156608458198757210492) + return kernel_cosl(x, z); + + /* cosl(Inf) is NaN, cosl(0) is 1 */ + else if (x + x == x && x != 0.0) + return x - x; /* NaN */ + + /* argument reduction needed */ + else + { + n = ieee754_rem_pio2l (x, y); + switch (n & 3) + { + case 0: + return kernel_cosl (y[0], y[1]); + case 1: + return -kernel_sinl (y[0], y[1], 1); + case 2: + return -kernel_cosl (y[0], y[1]); + default: + return kernel_sinl (y[0], y[1], 1); + } + } +} + +#endif + +#if 0 +int +main (void) +{ + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *29)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *2)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *30)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *4)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *32)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *2/3)); + printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *4/3)); +} +#endif |