1/* s_sinl.c -- long double version of s_sin.c.
2 * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
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
12 * is preserved.
13 * ====================================================
14 */
15
16/* sinl(x)
17 * Return sine function of x.
18 *
19 * kernel function:
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
23 *
24 * Method.
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.
28 * We have
29 *
30 * n sin(x) cos(x) tan(x)
31 * ----------------------------------------------------------
32 * 0 S C T
33 * 1 C -S -1/T
34 * 2 -S -C T
35 * 3 -C S -1/T
36 * ----------------------------------------------------------
37 *
38 * Special cases:
39 * Let trig be any of sin, cos, or tan.
40 * trig(+-INF) is NaN, with signals;
41 * trig(NaN) is that NaN;
42 *
43 * Accuracy:
44 * TRIG(x) returns trig(x) nearly rounded
45 */
46
47#include <errno.h>
48#include <math.h>
49#include <math_private.h>
50
51_Float128 __sinl(_Float128 x)
52{
53 _Float128 y[2],z=0;
54 int64_t n, ix;
55
56 /* High word of x. */
57 GET_LDOUBLE_MSW64(ix,x);
58
59 /* |x| ~< pi/4 */
60 ix &= 0x7fffffffffffffffLL;
61 if(ix <= 0x3ffe921fb54442d1LL)
62 return __kernel_sinl(x,z,0);
63
64 /* sin(Inf or NaN) is NaN */
65 else if (ix>=0x7fff000000000000LL) {
66 if (ix == 0x7fff000000000000LL) {
67 GET_LDOUBLE_LSW64(n,x);
68 if (n == 0)
69 __set_errno (EDOM);
70 }
71 return x-x;
72 }
73
74 /* argument reduction needed */
75 else {
76 n = __ieee754_rem_pio2l(x,y);
77 switch(n&3) {
78 case 0: return __kernel_sinl(y[0],y[1],1);
79 case 1: return __kernel_cosl(y[0],y[1]);
80 case 2: return -__kernel_sinl(y[0],y[1],1);
81 default:
82 return -__kernel_cosl(y[0],y[1]);
83 }
84 }
85}
86weak_alias (__sinl, sinl)
87