1 /* @(#)s_sin.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
13 #include <sys/cdefs.h>
14 __FBSDID("$FreeBSD$");
17 * Return sine function of x.
20 * __kernel_sin ... sine function on [-pi/4,pi/4]
21 * __kernel_cos ... cose function on [-pi/4,pi/4]
22 * __ieee754_rem_pio2 ... 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
50 #define INLINE_REM_PIO2
51 #include "math_private.h"
52 #include "e_rem_pio2.c"
65 if(ix <= 0x3fe921fb) {
66 if(ix<0x3e500000) /* |x| < 2**-26 */
67 {if((int)x==0) return x;} /* generate inexact */
68 return __kernel_sin(x,z,0);
71 /* sin(Inf or NaN) is NaN */
72 else if (ix>=0x7ff00000) return x-x;
74 /* argument reduction needed */
76 n = __ieee754_rem_pio2(x,y);
78 case 0: return __kernel_sin(y[0],y[1],1);
79 case 1: return __kernel_cos(y[0],y[1]);
80 case 2: return -__kernel_sin(y[0],y[1],1);
82 return -__kernel_cos(y[0],y[1]);
87 #if (LDBL_MANT_DIG == 53)
88 __weak_reference(sin, sinl);