1 /* s_cosl.c -- long double version of s_sin.c.
2 * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz.
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
13 * ====================================================
17 * Return sine function of x.
20 * __kernel_sinl ... sine function on [-pi/4,pi/4]
21 * __kernel_cosl ... cose function on [-pi/4,pi/4]
22 * __ieee754_rem_pio2l ... argument reduction routine
25 * Let S,C and T denote the sin, cos and tan respectively on
26 * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
27 * in [-pi/4 , +pi/4], and let n = k mod 4.
30 * n sin(x) cos(x) tan(x)
31 * ----------------------------------------------------------
36 * ----------------------------------------------------------
39 * Let trig be any of sin, cos, or tan.
40 * trig(+-INF) is NaN, with signals;
41 * trig(NaN) is that NaN;
44 * TRIG(x) returns trig(x) nearly rounded
57 long double cosl(long double x)
59 long double y[2],z=0.0L;
63 if(x >= -0.7853981633974483096156608458198757210492 &&
64 x <= 0.7853981633974483096156608458198757210492)
65 return kernel_cosl(x, z);
67 /* sinl(Inf or NaN) is NaN, sinl(0) is 0 */
68 else if ((x + x == x && x != 0.0) || x != x)
71 /* argument reduction needed */
73 n = ieee754_rem_pio2l(x,y);
75 case 0: return kernel_cosl(y[0],y[1]);
76 case 1: return -kernel_sinl(y[0],y[1],1);
77 case 2: return -kernel_cosl(y[0],y[1]);
79 return kernel_sinl(y[0],y[1],1);
88 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492));
89 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *29));
90 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *2));
91 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *30));
92 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *4));
93 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *32));
94 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *2/3));
95 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *4/3));