xref: /netbsd-src/lib/libm/src/s_sinf.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /* s_sinf.c -- float version of s_sin.c.
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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 #include <sys/cdefs.h>
17 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: s_sinf.c,v 1.7 2002/05/26 22:01:58 wiz Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 float
25 sinf(float x)
26 {
27 	float y[2],z=0.0;
28 	int32_t n, ix;
29 
30 	GET_FLOAT_WORD(ix,x);
31 
32     /* |x| ~< pi/4 */
33 	ix &= 0x7fffffff;
34 	if(ix <= 0x3f490fd8) return __kernel_sinf(x,z,0);
35 
36     /* sin(Inf or NaN) is NaN */
37 	else if (ix>=0x7f800000) return x-x;
38 
39     /* argument reduction needed */
40 	else {
41 	    n = __ieee754_rem_pio2f(x,y);
42 	    switch(n&3) {
43 		case 0: return  __kernel_sinf(y[0],y[1],1);
44 		case 1: return  __kernel_cosf(y[0],y[1]);
45 		case 2: return -__kernel_sinf(y[0],y[1],1);
46 		default:
47 			return -__kernel_cosf(y[0],y[1]);
48 	    }
49 	}
50 }
51