1 /* s_cosl.c -- long double version of s_cos.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 cosine function of x.
20 * __kernel_sinl ... sine function on [-pi/4,pi/4]
21 * __kernel_cosl ... cosine 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
48 #include "math_private.h"
49 #include <math_ldbl_opt.h>
52 long double __cosl(long double x
)
58 long double y
[2],z
=0.0L;
62 GET_LDOUBLE_MSW64(ix
,x
);
65 ix
&= 0x7fffffffffffffffLL
;
66 if(ix
<= 0x3fe921fb54442d18LL
)
67 return __kernel_cosl(x
,z
);
69 /* cos(Inf or NaN) is NaN */
70 else if (ix
>=0x7ff0000000000000LL
)
73 /* argument reduction needed */
75 n
= __ieee754_rem_pio2l(x
,y
);
78 return __kernel_cosl(y
[0],y
[1]);
80 return -__kernel_sinl(y
[0],y
[1],1);
82 return -__kernel_cosl(y
[0],y
[1]);
84 return __kernel_sinl(y
[0],y
[1],1);
88 long_double_symbol (libm
, __cosl
, cosl
);