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 * ====================================================
22 * Return sine function of x.
25 * __kernel_sinl ... sine function on [-pi/4,pi/4]
26 * __kernel_cosl ... cose function on [-pi/4,pi/4]
27 * __ieee754_rem_pio2l ... argument reduction routine
30 * Let S,C and T denote the sin, cos and tan respectively on
31 * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
32 * in [-pi/4 , +pi/4], and let n = k mod 4.
35 * n sin(x) cos(x) tan(x)
36 * ----------------------------------------------------------
41 * ----------------------------------------------------------
44 * Let trig be any of sin, cos, or tan.
45 * trig(+-INF) is NaN, with signals;
46 * trig(NaN) is that NaN;
49 * TRIG(x) returns trig(x) nearly rounded
58 long double cosl(long double x)
60 long double y[2],z=0.0L;
63 /* cosl(NaN) is NaN */
68 if(x >= -0.7853981633974483096156608458198757210492 &&
69 x <= 0.7853981633974483096156608458198757210492)
70 return kernel_cosl(x, z);
72 /* cosl(Inf) is NaN, cosl(0) is 1 */
73 else if (x + x == x && x != 0.0)
76 /* argument reduction needed */
78 n = ieee754_rem_pio2l(x,y);
80 case 0: return kernel_cosl(y[0],y[1]);
81 case 1: return -kernel_sinl(y[0],y[1],1);
82 case 2: return -kernel_cosl(y[0],y[1]);
84 return kernel_sinl(y[0],y[1],1);
93 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492));
94 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *29));
95 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *2));
96 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *30));
97 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *4));
98 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *32));
99 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *2/3));
100 printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *4/3));