1 /* s_cosl.c -- long double version of s_cos.c.
5 * ====================================================
6 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 * Developed at SunPro, a Sun Microsystems, Inc. business.
9 * Permission to use, copy, modify, and distribute this
10 * software is freely granted, provided that this notice
12 * ====================================================
16 * Return cosine function of x.
19 * __kernel_sinl ... sine function on [-pi/4,pi/4]
20 * __kernel_cosl ... cosine function on [-pi/4,pi/4]
21 * __ieee754_rem_pio2l ... argument reduction routine
24 * Let S,C and T denote the sin, cos and tan respectively on
25 * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
26 * in [-pi/4 , +pi/4], and let n = k mod 4.
29 * n sin(x) cos(x) tan(x)
30 * ----------------------------------------------------------
35 * ----------------------------------------------------------
38 * Let trig be any of sin, cos, or tan.
39 * trig(+-INF) is NaN, with signals;
40 * trig(NaN) is that NaN;
43 * TRIG(x) returns trig(x) nearly rounded
48 #include <math_private.h>
49 #include <libm-alias-ldouble.h>
51 _Float128
__cosl(_Float128 x
)
57 GET_LDOUBLE_MSW64(ix
,x
);
60 ix
&= 0x7fffffffffffffffLL
;
61 if(ix
<= 0x3ffe921fb54442d1LL
)
62 return __kernel_cosl(x
,z
);
64 /* cos(Inf or NaN) is NaN */
65 else if (ix
>=0x7fff000000000000LL
) {
66 if (ix
== 0x7fff000000000000LL
) {
67 GET_LDOUBLE_LSW64(n
,x
);
74 /* argument reduction needed */
76 n
= __ieee754_rem_pio2l(x
,y
);
78 case 0: return __kernel_cosl(y
[0],y
[1]);
79 case 1: return -__kernel_sinl(y
[0],y
[1],1);
80 case 2: return -__kernel_cosl(y
[0],y
[1]);
82 return __kernel_sinl(y
[0],y
[1],1);
86 libm_alias_ldouble (__cos
, cos
)