xref: /netbsd-src/lib/libm/src/s_sinf.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
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 1.6 1999/07/02 15:37:43 simonb Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 #ifdef __STDC__
25 	float sinf(float x)
26 #else
27 	float sinf(x)
28 	float x;
29 #endif
30 {
31 	float y[2],z=0.0;
32 	int32_t n, ix;
33 
34 	GET_FLOAT_WORD(ix,x);
35 
36     /* |x| ~< pi/4 */
37 	ix &= 0x7fffffff;
38 	if(ix <= 0x3f490fd8) return __kernel_sinf(x,z,0);
39 
40     /* sin(Inf or NaN) is NaN */
41 	else if (ix>=0x7f800000) return x-x;
42 
43     /* argument reduction needed */
44 	else {
45 	    n = __ieee754_rem_pio2f(x,y);
46 	    switch(n&3) {
47 		case 0: return  __kernel_sinf(y[0],y[1],1);
48 		case 1: return  __kernel_cosf(y[0],y[1]);
49 		case 2: return -__kernel_sinf(y[0],y[1],1);
50 		default:
51 			return -__kernel_cosf(y[0],y[1]);
52 	    }
53 	}
54 }
55