1 /* @(#)s_sin.c 5.1 93/09/24 */
2 /* $FreeBSD: head/lib/msun/src/s_sin.c 218509 2011-02-10 07:37:50Z das $ */
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
7 * Developed at SunPro, a Sun Microsystems, Inc. business.
8 * Permission to use, copy, modify, and distribute this
9 * software is freely granted, provided that this notice
11 * ====================================================
15 * Return sine function of x.
18 * __kernel_sin ... sine function on [-pi/4,pi/4]
19 * __kernel_cos ... cose function on [-pi/4,pi/4]
20 * __ieee754_rem_pio2 ... argument reduction routine
23 * Let S,C and T denote the sin, cos and tan respectively on
24 * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
25 * in [-pi/4 , +pi/4], and let n = k mod 4.
28 * n sin(x) cos(x) tan(x)
29 * ----------------------------------------------------------
34 * ----------------------------------------------------------
37 * Let trig be any of sin, cos, or tan.
38 * trig(+-INF) is NaN, with signals;
39 * trig(NaN) is that NaN;
42 * TRIG(x) returns trig(x) nearly rounded
48 #define INLINE_REM_PIO2
49 #include "math_private.h"
50 #include "e_rem_pio2.c"
63 if(ix <= 0x3fe921fb) {
64 if(ix<0x3e500000) /* |x| < 2**-26 */
65 {if((int)x==0) return x;} /* generate inexact */
66 return __kernel_sin(x,z,0);
69 /* sin(Inf or NaN) is NaN */
70 else if (ix>=0x7ff00000) return x-x;
72 /* argument reduction needed */
74 n = __ieee754_rem_pio2(x,y);
76 case 0: return __kernel_sin(y[0],y[1],1);
77 case 1: return __kernel_cos(y[0],y[1]);
78 case 2: return -__kernel_sin(y[0],y[1],1);
80 return -__kernel_cos(y[0],y[1]);
85 #if (LDBL_MANT_DIG == 53)
86 __weak_reference(sin, sinl);